Talk:Natural selection/Archive 8

Archive 5

Archive 6

Archive 7

Archive 8

Archive 9

Archive 10

Archive 11

Extinction and NatSel

Ok, this is getting interesting. Basically, when a species goes extinct because it is maladapted, it is not Natural Selection that is causing it, but other processes. That is just to weird... What are those processes and how are they different from NatSel. -- Kim van der Linde ^{at venus} 04:27, 9 July 2006 (UTC)

If we have a few children left in a sexually reproducing population and they are all eaten by a predator before reproductive age I fail to see how this could be drift. Since the predator didn´t select any particular children to eat, it just ate them all, it is arguably not selection either. — Axel147 14:00, 9 July 2006 (UTC)

Basic problems: 1) whatever natural selection is, we'll all agree that there is no intelligent designer behind it. So how does natural selection "know" whether there are only a few individiuals or just one individual or many? 2) how do we know the predator didn't select children to eat? Who should we ask? Gleng 21:26, 9 July 2006 (UTC)

Just some points of clarification. The reason I´m ruling rule out drift is because this occurs as a result of sampling. Extinction happens to an entire population rather than a sample of it so (unless we widen our use of drift to include random processes that can happen to entire populations) extinction cannot be explained by drift. Natural selection would also be ruled out if the children had equal fitness. However, I don't see any of this as problematical as (in a sense) extinction is not evolution: gene frequencies do not change from one value to another. Instead they 'change' to an undefined value, no value at all.

So drift cannot result in extinction of species, but it can lead to extinction of traits within a species. The liklihood of a trait surviving extinction (given enough time) depends on its starting frequency and its relative fitness. With a low population size starting frequency (drift) is the dominant factor, whereas in a large population relative fitness (natural selection) dominates. Despite this drift is still directionless in that it doesn't alter the expected frequency of the trait. (In a similar way I can still run out of money playing a gambling machine even if it is biased in my favour, but this is less likely to happen if I bet the same amount of money in small stakes.)

Just to check we are all on the same page here let's see what happens in this case. We have 10 phenotypically different individuals with equal fitness. 5 get eaten. Gene frequencies change and our population has evolved. Now is this caused by drift or natural selection? It has to be drift. Sure, some traits are preserved while other equally fit alternatives are eliminated. But differences in traits did not influence the process. Natural selection is the extent to which reproduction is biased by trait differences. But in this case there are no fitness differences, no traits have additonal use or confer additional benefits on our individuals. There is nothing for nature to choose between and therefore no natural selection. — Axel147 16:15, 10 July 2006 (UTC)

How do you know there are no fitness differences except by who survives?Gleng 20:23, 10 July 2006 (UTC)

Well biologists may only be able to measure fitness differences by looking at who survives. That doesn't mean we have to define natural selection in terms of a result. It is more like a starting point: is there anything to select? We can imagine a predator looking for 5 who were easier to kill. They all happened to have the same overall fitness even though some were slower but stronger. So it just ate 5 at random. (I´m simplifying a bit here to illustrate the point.)

Let´s do an analogy with artificial selection. Imagine I have a bag of 10 balls: 6 red and 4 green. If I pick 3 green balls this is artifical selection. But instead if I pick 3 ´red or green´ balls each ball has equal chance of coming up. This is no longer artificial selection but random sampling. (And either colour may become ´extinct´.) — Axel147 23:16, 10 July 2006 (UTC)

Maybe. But we don't know and can't know. You're trying to define natural selection as some separate force, some metaphysical power that has a special meaning, in ways that can be taken as ascribing it some purpose reflecting some underlying direction or intelligence, or as something that only some overseeing intelligence can divine. There is a clear danger of "deifying" concepts, and this brings problems. Look at your answer above. Fitness is not an absolute, because it depends on the environment in its most broad sense - an organism might be well fitted to one environment but badly adapted for another, and the environment constantly changes - not least because in part the environment includes all the other individuals present within it. So it isn't really true to think of fitness as something independent of survival and reproduction - in the end that's all there is - fitness is survival and reproduction, there's nothing else. We can measure the contribution of a trait to fitness by estimating its value for survival and reproduction if we have enough representatives of the trait and enough data. But if we can't measure these because we don't have enough data or the sample is too small, it doesn't make sense to say that there is some different force acting or some different explanation. Gleng 09:54, 11 July 2006 (UTC)

I am most certainly not trying to define natural selection as a 'metaphysical power that has special meaning'! And I think you are wrong about fitness. Fitness is certainly different from actual survival and reproductive success. It is like life expectancy. I may have a high life expectancy but could get hit by a bus tomorrow. In terms of measurement I said the definition of natural selection should hold firm irrespective of man´s difficulties in measuring it. — Axel147 12:17, 11 July 2006 (UTC)

Don't mean to imply that you're intending this consequence. I was just trying to brutally exclude any sense in which there is someone or something that "does" the natural selecting. The argument about fitness is a universal problem about defining probabilities. Probabilities are estimates of the likelihood of an event happening. After the event there are no probabilities, only certainties. So we can talk about the probability of Italy winning the world cup only before; after, it no longer makes sense. So if you see fitness as probability, like life expectancy, it is an imperfect estimate based on incomplete knowledge; with complete knowledge, there would be no probability, only certainty, the certainties of who will survive and who won't. So I don't think you can ever separate fitness from how it's measured; the estimate will change depending on how much knowledge is available to you.Gleng 13:16, 11 July 2006 (UTC)

Italy´s probability of winning the world cup before the final was 56% (according to the odds on betfair). That still has explanatory value even now: it helps explain why they won. (It is just that it no longer has predictive value.) — Axel147 14:43, 11 July 2006 (UTC)

This is what I'm trying to avoid; it doesn't explain anything - as an explanation it is irretrievably circular; it reduces to they won because they were more likely to win Gleng 15:57, 11 July 2006 (UTC)

I think you're trapped in endless paradoxes. If you want to keep natural selection as meaning the theory of evolution by natural selection, OK, this may be common useage. But if so, don't try to use this also as a rigorous definition that you can use coherently in a logical argument. Gleng 09:54, 11 July 2006 (UTC)

I´m not trapped in endless paradoxes and, believe it or not, I´m no longer arguing the definitional point about inheritance. In these arguments I am using standard phenotypic defintions e.g. non-random differential reproduction.

Returning to my example I was suggesting the predator was performing the role of nature single-handedly. Let's imagine instead that 5 of the individuals get fat. Say this increases their risk of predation but at the same time reduces their susceptibility to disease, in such a way that overall fitness is unchanged. The predator decides to have a meal of 3 individuals, while disease kills 2. Now of course it is true to say the predator was likely to have eaten fat individuals. Similiary the disease is more likely to have killed thin ones. We could say the predator selected fat individuals, while disease selected thin ones. (Observation lifted from Sober.) But overall there were no fitness differences. 'Nature' overall did not do any selecting with respect to overall reproductive success. There was nothing to choose between these individuals in terms of overall reproductive success. As such there is no natural selection.

Note that unless we have this distinction it does not make sense to think of natural selection as one mechanism of evolution and genetic drift as a different one. Natural selection would subsume genetic drift. (I wouldn't have a problem with this view but genetic drift would then become the stochastic component of natural selection. I don't think this is standard?) — Axel147 12:17, 11 July 2006 (UTC)

Seems to be how drift is defined in WP.Gleng 13:16, 11 July 2006 (UTC)

Adam and Eve

Suppose we have two individuals in a population. Let´s call them Adam and Eve (just to play devil´s, or god´s, advocate). The point I am making is whether they go extinct or have children has nothing to do with natural selection. But is what happens next caused by divine intervention? No, of course it isn´t, I haven´t suddenly turned creationist — it is just evolution by a different mechanism!

If Adam and Eve´s reproductive success are tied together they must both have equal fitness. (And this is true even if Eve is susceptible to disease and Adam is not.) So Adam and Eve and all their traits have equal chance of reproducing. Natural selection cannot occur because it has no material to act on. There is no variation. It is only when they have children that fitness differences arise.

Clearly what happens does depend on the liklihood of Adam and Eve surviving the prevailing conditions and that is influenced by their characteristics. But we are not forced to label all natural processes that impinge upon reproductive success as 'natural selection'.

Natural selection requires variation in fitness before it can occur at all (and it requires heritable variation in fitness for it to produce evolutionary response).

(I realise we could puncture this argument by trying to 'force' fitness differences. We could argue Adam is fitter because he might reproduce with his daughter. Or we could talk about cheating during meiosis. But this is not the point. The point is that we are not obliged to name all process that influence reproductive success as 'natural selection'. Natural selection is the set of processes that bias reproductive success according to phenotypic differences.) — Axel147 14:43, 11 July 2006 (UTC)

"Natural selection requires variation in fitness before it can occur at all" I think we've probably played this out, and it has been fun :) As a last riposte I'd just say that natural selection requires that some survive and some do not, and fitness simply is an estimate of who is likely to survive. If we had enough knowledge, our estimate would be certain knowledge of who would survive and who would not; as our knowledge is imperfect we can only make a guess, and the value we give to fitness depends on how much knowledge we have. For Adam and Eve, their fitness is 1 or 0. Now while we know that there are only Adam and Eve, they don't know that - and for all we know there might have been a million others who somehow failed to find the apple. Now my only point is that you cannot sensibly describe what happens to them as natural selection or not depending on whether there are many others or no others. What happens and why it happens to them is the same, unless you think that the mere existence of other people somewhere in the garden alters the nature of the influences on A and E. So I'd say that natural selection is simply to be understood as the absence of artificial selection - it is the assertion of the absence of a God, a designer, a directing intelligence. It is whatever happens that means that some die and some don't. And that this, this absence of direction, this absence of intelligence, when there is variation and heritability, is enough to result in adaptive evolution, is the radical ideaGleng 15:57, 11 July 2006 (UTC)

The problem we are faced with (Kim´s orginal concern I think) is that if a lion happens to eat one of a species it probably doesn't know or care whether it is the last one. From its perspective the process is the same whether or not it causes extinction. The only answer I have to this is that from nature´s perspective there is no choice to make between individuals of the same species if we are down to just one. (One way round this problem is by dropping the word 'process' out of the definition as many authors do e.g. Futyama. But I not suggesting we do this.)

I agree that in a sense nature is still 'selecting' whether an individual survives or not, but I don´t think this is what we mean by 'natural selection'. The distinction is important to separate (conceptually at least) processes that may change gene frequencies in a predictable direction, from those which alter gene frequencies at random. Here is a published view on this. Once again Sober p159:

Natural selection is one mechansim that can destroy variation. For it to act at all, there must exist variation (in fitness). But once a selection process begins it gradually destroys the conditions needed for its continued operation. Selection eliminates variation in fitness, and thereby brings itself to a halt.

— Axel147 17:42, 12 July 2006 (UTC)

"Selection eliminates variation in fitness, and thereby brings itself to a halt." This may be Sober´s POV and perhaps there is a place for it but I do not think it is a fair representation of mainstream theory of evolution and natural selection. Sober´s claim (in this one sentence at least) is simply not true. It would be true only if one sees variation as a precondition and in static terms. This is consistent with creationism (we start out with all the species God created, though some are now extinct). Darwin understood that there must be constant forces generating variation, even though he did not know that they are. in other words, variation is not a chronological precondition for NS, it is a conceptual precondition. Variation itself is not static, it is not that there "was" variation at one point in time. Just as there are selective forces, there are mechanisms that lead to variation. it is a constant process. user:Slrubenstein

For particular alleles, and for everything but balancing selection, this is true, though. Selection produces fixation, which means there is no variation in fitness any more - at that particular site. Graft 19:16, 14 July 2006 (UTC)

Just to clarify the context, Sober is talking about natural selection acting by itself here. Of course in practice there are mechanisms to generate and preserve variation. For a population of phenotypes (and this applies at site level in Graft´s balancing selection case)

1. Natural selection does its job of eliminating the unfit
2. ´Mendelism´ does the job of re-creating variation (in fitness)

So although in theory natural selection could grind to a halt (if everyone had equal fitness), it would soon be up and running again as soon as individuals reproduce (assuming no extinction). — Axel147 23:22, 14 July 2006 (UTC)

For completeness I suppose I should add that if one considers 'differential speciation' to be a form of higher level natural selection e.g. Gould, extinction could count as a form of natural selection after all! (If we have more than one species.) — Axel147 13:19, 22 July 2006 (UTC)

Yeah, you know, there are reasons why Gould's reputation among theorists is not quite the same as it is in the general public/popular press. Pete.Hurd 18:10, 22 July 2006 (UTC)

Inconsistent use of the word 'trait'

According to Wiki 'In biology, a trait or character is a genetically inherited feature of an organism.' If this is true why does the article say 'but only the heritable component of a trait will be passed on to the offspring'. Which is correct? Is a trait by definition heritable? — Axel147 20:20, 16 July 2006 (UTC)

We are using trait in the original, normal language definition, as a distinguishing characteristic of an individual rather than the more recent more specialised sense. Science has a way of hi-jacking common words; I've no idea what we should do - maybe a footnote?Gleng 20:42, 16 July 2006 (UTC)

I corrected the article on that point. [1] Traits can be fully or partly genetic, or not at all. Hence QTL analysis - carried out when the inheritance of the trait is not exactly known. - Samsara (talk • contribs) 08:17, 17 July 2006 (UTC)

Good, what corrrection are you putting in? Maybe I'm just being pedantic here, but we also using trait inconsistently in another respect: in the opening line but not elsewhere it refers to the state or 'value' of a feature (e.g. brown vs. eye colour). Also suggestions traits can be decomposed into parts some of which are heritable - different saying a trait as a single entity has different extents to which it is heritable. — Axel147 08:32, 17 July 2006 (UTC)

Unfortunately, trait is not used consistently in genetics. The Stansfield dictionary equates trait with character and phenotype (as does Hartl's old Human Genetics text). Some people use trait to refer to carriers, such as talking about individuals who are sickle-cell carriers as having sickle trait (vs. sickle-cell disease for homozygotes). Still others (myself included) use trait to refer to the gene, with characteristic as the phenotype (I don't know when I picked that up. It may have been when I was teaching Human Genetics). Ted^Talk/_{Contributions} 13:47, 18 July 2006 (UTC)

Fitness and Ecological Selection

In the fitness entry we still have the other use! 'If differences in individual genotypes affect fitness, then the frequencies of the genotypes will change over generations; the genotypes with higher fitness become more common. This process is called natural selection.'

Similarly, ecological selection (commonly natural selection excluding sexual selection)....

1. Ecological refers to strictly ecological processes that operate on a species' inherited traits without reference to mating or secondary sex characteristics (Ecological selection)
2. Ecological selection occurs when organisms that survive and reproduce increase the frequency of their genes in the gene pool over those that do not survive. (Evolution)
3. Ecological selection covers any mechanism of selection as a result of the environment. (Natural selection)

These articles seem stable but inconsistent. I am no longer fresh to this so don't know if it's important to do anything about it! — Axel147 17:08, 10 August 2006 (UTC)

Natural selection does not include sexual selection, they are different. Slrubenstein | Talk 19:10, 10 August 2006 (UTC)

This has always been my understanding as well. The relevant WP entries have always (since I started paying attention, [2]) maintained that SL is a subset of NL. It would be nice if someone went and fixed and referenced this. Pete.Hurd 19:38, 10 August 2006 (UTC)

Darwin considered sexual selection a subset of natural selection, and this distinction would seem to be upheld in that we do not count sexual selection as a fifth microevolutionary force. Mate choice and competition evolve as a result of natural selection, so how can they not be a subset? - Samsara (talk • contribs) 20:19, 10 August 2006 (UTC)

Samsara, perhaps I was mistaken. I thought Darwin made this distinction in OoS. I defer to you and others, Slrubenstein | Talk 20:27, 10 August 2006 (UTC)

Hmmm, my students seem to have wandered off with the best references, but they've left Helena Cronin behind, and she has a chapter on this, Ch 10. It begins "For classical Darwinism sexual selection was an oddity, entirely different from natural selection and generally opposed to it..." then documents the shift, over time, to incorporating intraspecific selection pressures (ie sexual selection) into "natural selection". Like I say, it's my impression that the view that SS is not a subset of NS is quite common (at least among the sexual selection crowd). Cronin seems to suggest that this view is still held by a minority. I'd be happier with references documenting the taxonomy of selection types presented in the selection article than an argument by pure logic. Because, even if this is the current view, it was not always that way. Pete.Hurd 21:29, 10 August 2006 (UTC)

Well, you're right about the direction of effects and the feeling that it was an oddity, but from my reading of The Descent of Man, and Selection in Relation to Sex (note the title!), there was no doubt in Darwin's mind that at the bottom of it was natural selection. - Samsara (talk • contribs) 21:35, 10 August 2006 (UTC)

Hmmm, ok, I'm wrong(ish) yet again. Endler's Natural selection in the wild replicates the taxonomy, but calls what selection has as "ecological selection" "narrow sense natural selection" and then has "narrow sense NS" + SS = NATURAL SELECTION. Endler presents a nice review... Endler says "Darwin (1859, p88; 1871) made a careful distinction between natural selection and sexual selection ..." my copies are (of course) elsewhere but it would be interesting to see what he says. Pete.Hurd 21:41, 10 August 2006 (UTC)

Sorry, Sexual selection is a integral part of Natural selection. The contrast is with artificial selection. -- Kim van der Linde ^{at venus} 03:44, 11 August 2006 (UTC)

Yes, I agree sexual selection is a subset of natural selection. But this is not in contrast with artificial selection: artificial selection (providing we are talking about differential reproduction of some biological entity) is also part of natural selection. I think this selection diagram is wrong. — Axel147 12:52, 11 August 2006 (UTC)

Sigh, artificial selection is not natural selection, even darwin makes that clear. -- Kim van der Linde ^{at venus} 17:24, 11 August 2006 (UTC)

Hmm... that distinction is a bit out of date, isn't it? I'm thinking about artificial selection in the 19th century, which wasn't much different from humans being domesticated from the savannah (EEA) into the metropolital environment, vs. today's breeding efforts using best linear unbiased predictors (BLUP) and QTL analysis, which is an entirely different kettle of fish. I see it more as something that Darwin used as an explanatory tool. Darwin, of course, saw the two as closely analogous, enacting the same process. I would say that sexual selection can be as much affected by bringing creatures into captivity as "ecological selection" can. I do wonder what textbooks say on this. - Samsara (talk • contribs) 13:31, 11 August 2006 (UTC)

The only difference between artificial selection and natural selection is that one is performed by something with a sense of agency (i.e. humans) while the other is not. Darwin invoked artificial selection because its powers of transformation over the form and function of the organism were well known in his day. The "natural" element is just Darwin saying, "OK, you know how people breed horses, right? Well imagine that nature is breeding the horses, just by the fact of its day-to-day existence!" It is, in the end, a difficult distinction in many cases, I think, for the same reasons we have trouble in identifying what exactly separates human agency from non-human agency (i.e. a human builds something and we call it agency; a beaver builds something and we call it an extended phenotype). --Fastfission 17:40, 11 August 2006 (UTC)

Yes. No need for Kim to sigh! Artificial selection is a special case of natural selection as long as biological entities are differentially reproducing. Sober agrees anyway...

Artificial selection is not selection that takes places outside of nature, but selection that occurs within a particular niche found in nature. The [Waddington] experiment involved the interaction of members of one species with members of another. The fact that one of those species happens to have been Homo sapiens sapiens does not affect the point. Artificial selection is a variety of natural selection; the relation is one of set inclusion, not disjointness.

— Axel147 18:12, 11 August 2006 (UTC)

So *all* selection is natural selection, and the word "natural" means nothing? Endler (1986) flat-out contradicts Sober's view. Pete.Hurd 20:07, 11 August 2006 (UTC)

Oh. What does Endler say? (I've only got the 1st chapter that you sent before.) What happens if I'm hungry and I go into the woods and shoot an animal. Is it natural selection? Does it make a difference if I eat it, kill it for fun or as an experiment? — Axel147 20:30, 11 August 2006 (UTC)

"Does it make a difference if I eat it, kill it for fun or as an experiment?" Hairsplitting sophistry. You're saying that there is no such thing as articifial selection, that the term is meaningless? Pete.Hurd 20:45, 11 August 2006 (UTC)

He's just saying that if you treat humans as part of the natural world then there is technically no ontological difference, since the distance between humans and the natural world is just a story humans like to tell themselves. But the term clearly has meaning, even if that meaning is largely as a heuristic—emphasizing the difference between active intelligent agency and un-guided natural operations maintains its usefulness in thinking about evolution, even if one doubts that human intelligence is removed from the sphere of the natural. --Fastfission 20:56, 11 August 2006 (UTC)

I agree with Fastfission here. — Axel147 21:00, 11 August 2006 (UTC)

The word 'natural' means something in that 'nature' is, metaphorically, the agent doing the selection. This from Wallace to Darwin is partly relevant and interesting anyway (abridged)...

My dear Darwin,— I have been so repeatedly struck by the utter inability of number of intelligent persons to see clearly, or at all, the self-acting and necessary effects of Natural Selection, that I am led to conclude that the term itself, and your mode of illustrating it however beautiful to many of us, are yet not the best adapted to impress it on the general naturalistic public...I think [the difficulty in understanding] arises almost entirely from your choice of the term Natural Selection, and so constantly comparing it in its effects to man's selection, and also to your so frequently personifying nature as 'selecting', as 'preferring', 'as seeking only the good of the species', etc., etc. To the few this is as clear as daylight, and beautifully suggestive, but to many it is evidently a stumbling block....I wish, therefore to suggest to you the possibility of entirely avoiding this source of misconception in your great work (if now not too late)...by adopting Spencer's term viz. 'Survival of the Fittest'. This term is a plain expression of the fact; 'Natural Selection' is a metaphorical expression of it, and to a certain degree indirect and incorrect, since, even personifying Nature, she does not so much select special variations as exterminate the most unfavourable ones.

— Axel147 21:00, 11 August 2006 (UTC)

There is a critically important distinction between artificial selection and natural selection, which I think is fundamental and essential not to blur. In Darwin's sense artificial selection involved design, directed intent. Natural selection does not. Gleng 19:22, 12 August 2006 (UTC)

Yes, I know what you mean. But I'm saying (like Sober) artificial selection is a special case of natural selection. It is still important to clearly identify what that special case is. 'Design, directed intent' do seem to be at the heart of it. I'm struggling with the exact boundary. Maybe one animal can kill another through intelligence or 'directed intent'? Maybe all selection involving man should be classified as 'artificial'? The more serious point is I think the opening sentence 'Natural selection is the process by which individual organisms with favorable traits are more likely to survive and reproduce' is correct. But you seem to be suggesting we need to qualify this with 'except if they are killed in experiments by man!' — Axel147 21:58, 12 August 2006 (UTC)

It's not ideal. It was and is obvious that artificial selection can change the form of species, but this process involves intent to produce that particular change, it is a deliberate exploitation of variation and inheritance by an intelligent designer. Darwin's insight was that no intent is necessary. I agree with you, that in the broad scheme of things then artificial selection is just part of our extended phenotype, but appreciating this requires both subtlety and rewriting Darwin even more extensively. I thnk it's important not to blur Darwin's insight that no designer is needed, so the distinction between artificial selection and natural selection is a useful one. Take away this and you don't need the word "natural" . Gleng 07:57, 14 August 2006 (UTC)

Yes, fair enough. I wonder if anyone thinks the Wiki artificial selection has got it wrong by including 'unintentional modification of a species through human actions'? If artificial selection is not a form of natural selection, this suggests an absurdity: man has evolved principally through artificial selection rather than natural selection! (In my view the meaning of natural selection does not depend how we define artificial selection so I'm not so concerned!) Maybe I'm just being pedantic, if so sorry! — Axel147 16:45, 14 August 2006 (UTC)

I hadn't seen that, and I agree with you; I think it is just silly not to see humans as part of the natural world.Gleng 14:08, 15 August 2006 (UTC)

I think insisting that artificial selection is a subset of natural selection through some reducio ad absurdium argument about humans not being "natural" airbrushes out a long, historically relevant, debate about teleology in selection. Pete.Hurd 17:22, 15 August 2006 (UTC)

i agree, hadn't meant to imply that I agreed that artifial selection should be classed in this way, but was agreeing that the definition of artificial selection appeared to be too broadGleng 17:37, 15 August 2006 (UTC)

Whups, I've made a misunderstanding, the comment was directed more at Axel, my bad. Pete.Hurd 18:48, 15 August 2006 (UTC)

No such airbrushing is needed! It is perfectly coherent to say artificial selection is a special case that requires intelligent manipulation, whereas natural selection in general does not. The point is natural selection can occur without intelligent manipulation, not that it always has to. Isn't the antibiotic resistance example to some degree artificial? — Axel147 12:09, 16 August 2006 (UTC)

Vandalism

The last time that I read this article, some idiot had written something about the new Kim Possible season. If the vandal is reading this, please note that we don't care about Kim Possible and that this page is about NATURAL SELECTION, just in case you haven't noticed that already. --71.140.114.12 19:45, 11 February 2007 (UTC)

Nominate for FA?

Guys, seeing how little the article has changed in recent weeks, and noting that it is well referenced and well illustrated, and also noting that my recent experience of peer review shows it to be much less active, and therefore much less useful, than FAC, can I ask you all whether you consider that FA status is desirable for this article, and would therefore like to apply for it? (FA has ups and downs - it will bring more people wanting to "improve" the article, but it also carries prestige...)

Many thanks,

Samsara (talk • contribs) 14:48, 16 August 2006 (UTC)

Personally I think that this article is clear and interesting, looking at it now with fairly fresh eyes some time after my last edit; there could usefully be some more illustrations perhaps, certainly a lead figure at the beginning? Maybe the lead picture should show the results of artificial selection that inspired Darwin - think it was the diversity of pigeons if I remember well, which I probably don't, paralleled with finch diversity? Gleng 20:54, 16 August 2006 (UTC)

I seem to remember seeing plates of finch beaks in biology textbooks. Maybe a free example exists or could be created. Unfortunately, drawing is not one of my strengths. I don't recall ever seeing an illustration of domestic pigeon diversification. We could try to polish the antibiotic illustration into something more tangible - many bacteria do have a distinct, recognisable shape. - Samsara (talk • contribs) 21:45, 17 August 2006 (UTC)

On page 18 of The Beak of the Finch are four finches drawn by Darwin from his journals. I don't know if these qualify as PD by now via this route, but I'm with Glen, Finches and Pigeons are the ideal candidates for illustrating this article. Pete.Hurd 22:33, 17 August 2006 (UTC)

If they're his original figures, then yes, c.f. Image:Darwins first tree.jpg. Seeing that you seem to have a copy of the book, could you scan and upload the figure? - Samsara (talk • contribs) 14:21, 18 August 2006 (UTC)

Is it this image? --Fastfission 17:05, 18 August 2006 (UTC)

Aye, that's the one Pete.Hurd 20:09, 18 August 2006 (UTC)

Now all it needs is a compelling caption. - Samsara (talk • contribs) 13:50, 19 August 2006 (UTC)

I was thinking it would be nice to have some text dealing with character displacement, sympatric and allopatric species and beak shape etc. It would make the figure all the more worthwhile, and would probably work best as another example section. What do you think? Pete.Hurd 14:39, 19 August 2006 (UTC)

Sounds good. Would also like to see adaptive radiation mentioned. I was intrigued by the fact that there are 13 main islands in the Galapagos archipelago, and 13 species of finch. I don't know the literature on these finches at all, so I'll leave it at that lest I embarrass myself. - Samsara (talk • contribs) 14:54, 19 August 2006 (UTC)

Actually, no, the speciation is much more complex, and each island has different species, and the interactions between the species is crucial to explain the variation in beak size. -- Kim van der Linde ^{at venus} 15:10, 14 September 2006 (UTC)

My thoughts what need to be done before considering FA:

1. references, more references and even more references. Most of it comes straight out of my mind, but there are references for it.
2. Lead section. To short, slightly incorrect. Individuals -> unit of selection, requires a mind warp to get that right as it becomes mind-numbing complex but needs to be accessable for lay people (that is why I skirted it when I rewrote it). Needs to include more of the main points of the main text.
3. Definition section needs to be rewritten.
4. Aspects like character displacement and adaptive radiation are nice additions to the evolution by means of Natrual selection section. If you want to do NatSel with that, it should be about how changes in the seed size between years affects the fitness of individuals and results in a changed beaksize in the next generation. You can make really perty graphs with that.

maybe I come up with some more things, but this is it for now. -- Kim van der Linde ^{at venus} 15:10, 14 September 2006 (UTC)

embryology

would sympathtic editors consider a positive vote here? [3]Slrubenstein | Talk 15:34, 23 August 2006 (UTC)

definition of natural selection and bacteria example

I apologize for the improper posting, I'm new to this. This whole section of a definition is lacking. I know of no definition that a majority of scientist would agree upon. Natural selection is measured as an outcome of reproductive success of genetic traits or genomic elements. Natural selection is a black box that should be filled with ecological contributions, population biology, neuroethology-animal behavior, proteogenomic interactions, and random chance. It may be better to state that is a measured outcome and the variables that produce it are complex and entail the aforementioned. GetAgrippa 12:48, 30 August 2006 (UTC) AFter closer scrutiny I think this is addressed.GetAgrippa 01:31, 31 August 2006 (UTC)

The bacteria example is too simplestic. Antibiotic resistance can occur by altering phenotypic expression in genetically identical strains, and by inhibition of growth-non-inheritable change so not evolution per se. Horizontal transfer also appears to be a source of antibiotic resistance from the huge reservoir of antibiotic resistance in soil bacteria, so it is not a mutation but gene gain. Science. 2006 Apr 28;312(5773):529.Science. 2006 Apr 28;312(5773):529. Science. 2006 Jan 20;311(5759):342-3. Science 15 April 1994 264: 375-382 [DOI: 10.1126/science.8153624] (in Articles) Science 10 September 2004 305: 1578-1579 [DOI: 10.1126/science.1103077] (in Perspectives GetAgrippa 13:25, 30 August 2006 (UTC)

Natural selection can occur with any mechanism that introduces new variation, or simply on pre-existing variation. In the example is it HGT or other mutations — presumably both? But I don't think it really matters so much from the point of view of giving a simple example of natural selection accessible to the layman. Maybe a slight tweak needed? — Axel147 19:09, 30 August 2006 (UTC)

After reading the reference to phenotypic natural selection ,then I guess the bacteria example holds even if it is just penotypic expression of a subpopulation or inhibition of growth could explain it without a mutation. . HGT is inheritable but an example of gene gain or gene network alteration. I have to admit phenotypic evolution personally bothers me from a developmental biology viewpoint and the fact that inheritable genomic change has historically been a mainstay of evolution theory, but that's personal so Get A grippa!! Hee, Hee. It maybe worthwhile to add that bacteria can acquire antibiotic tolerance by HGT from the soil genomic reservoir and that mutations are not the only mechanism. You could also link phenotypic modulation and non-heritable evolution. That maybe too confusing, but it demonstrates the many pathways of evolution. Axel maybe you could recommend a slight tweak that would be meaningful and cohesive witht the rest? I agree with simple examples, but they should also be complete and true to what is known (maybe a HGT reference?), but I can see how it could create confusion if taken too far. GetAgrippa 11:41, 31 August 2006 (UTC)

In order to make my stance more clear I provide these abstracts for quick review: Five point mutations in a particular ß-lactamase allele jointly increase bacterial resistance to a clinically important antibiotic by a factor of 100,000. In principle, evolution to this high-resistance ß-lactamase might follow any of the 120 mutational trajectories linking these alleles. However, we demonstrate that 102 trajectories are inaccessible to Darwinian selection and that many of the remaining trajectories have negligible probabilities of realization, because four of these five mutations fail to increase drug resistance in some combinations. Pervasive biophysical pleiotropy within the ß-lactamase seems to be responsible, and because such pleiotropy appears to be a general property of missense mutations, we conclude that much protein evolution will be similarly constrained. This implies that the protein tape of life may be largely reproducible and even predictable. Science, Vol. 312, Issue 5770, 111-114. 2006.

The emergence of multidrug-resistant bacteria is a phenomenon of concern to the clinician and the pharmaceutical industry, as it is the major cause of failure in the treatment of infectious diseases. The most common mechanism of resistance in pathogenic bacteria to antibiotics of the aminoglycoside, beta-lactam (penicillins and cephalosporins), and chloramphenicol types involves the enzymic inactivation of the antibiotic by hydrolysis or by formation of inactive derivatives. Such resistance determinants most probably were acquired by pathogenic bacteria from a pool of resistance genes in other microbial genera, including antibiotic-producing organisms. The resistance gene sequences were subsequently integrated by site-specific recombination into several classes of naturally occurring gene expression cassettes (typically "integrons") and disseminated within the microbial population by a variety of gene transfer mechanisms. Although bacterial conjugation once was believed to be restricted in host range, it now appears that this mechanism of transfer permits genetic exchange between many different bacterial genera in nature. Science, Vol 264, Issue 5157, 375-382.1994.

When research labs began churning out the genome sequences of a multitude of microbes in the late 1990s, microbiologists got a big surprise: Many organisms seem to be swapping genes with abandon from strain to strain, even across species. Astonishingly, for example, about 25% of the genome of the gut bacterium Escherichia coli turns out to have been acquired from other species. The realization that gene swapping, or horizontal gene transfer as it is called, is a common phenomenon has thrown the field into a tizzy. The implications, says microbiologist Matthew Kane of the National Science Foundation in Arlington, Virginia, "are very, very broad." Borrowed genes can spread antibiotic resistance from one pathogen to another or help an organism survive new or stressful conditions. And it happens often enough to alter the dynamics of microbial communities and even affect the course of evolution……Science, Vol 305, Issue 5682, 334-335.2004.

Microbial resistance to antibiotics currently spans all known classes of natural and synthetic compounds. It has not only hindered our treatment of infections but also dramatically reshaped drug discovery, yet its origins have not been systematically studied. Soil-dwelling bacteria produce and encounter a myriad of antibiotics, evolving corresponding sensing and evading strategies. They are a reservoir of resistance determinants that can be mobilized into the microbial community. Study of this reservoir could provide an early warning system for future clinically relevant antibiotic resistance mechanisms. Science, Vol. 311. Issue 5759 374-377. 2006

It would seem that HGT should be mentioned as a significant factor or the major factor in antibiotic resistance.GetAgrippa 12:27, 31 August 2006 (UTC)

I think you are right that HGT deserves a mention. But I'm not sure about the spin! Evolution by natural selection is the idea that successful organisms will transmit (some of) their characteristics to other organisms more often than unsuccessful rivals. This is true whether this happens 'horizontally' or 'vertically'. But admittedly if genes can jump freely from one organism to another this might undermine the individual bacterium as the unit of selection in this case. We would have to replace 'differential reproduction' with 'differential transmission'. Or, more sensibly, view this as an example of natural selection of (ultra) selfish genes.

Maybe HGT should be mentioned briefly (so as not to detract from the main point of the example) or the example should be changed? I wonder if anyone else has a view on this, before proposing anything. — Axel147 18:14, 31 August 2006 (UTC)

Thank you Axel for your perspective. The more I read it seems HGT is the prevaling thought, however I agree it would undermine the example to a degree. It should be just a simple straightforward example. The example is accurate and occurs, but the interest in HGT is growing and appears to be significant. I'm like you, it would be nice for some others to chime in. Perhaps I should follow the motto "Keep it simple stupid" and just forget it, or mention HGT further down in a separate area and specifically mention bacteria and HGT antibiotic resistance as new concern?GetAgrippa 19:34, 31 August 2006 (UTC)

I went ahead and added my thoughts on HGT in antibiotic resistance. I stated that mutations ocurr in nature and the significance ,and then went on to mention HGT as a growing reality in nature.GetAgrippa 08:41, 3 September 2006 (UTC)

Phenotypic natural selection

Phenotypic plasiticity is heritable in birds and insects as I recollect from more recent studies. I'll find references.GetAgrippa 19:50, 3 September 2006 (UTC)

Some are phenotypes are heritable and some are not, so "forget about it". GetAgrippa 18:45, 4 September 2006 (UTC)

Grin, selection on phentotypic plasticity can even be phenotypically plastic, just to make it even more complex. In the end, phenotypic plasticity is just a version of an GxE interaction. A good article dealing with this is: Schlichting, C. D. and H. Smith (2002). "Phenotypic plasticity: linking molecular mechanisms with evolutionary outcomes." Evolutionary Ecology 16(3): 189-211. -- Kim van der Linde ^{at venus} 14:57, 14 September 2006 (UTC)

Is the example too technical?

I feel the example has now become too technical and is likely to put off non-biologists. (HGT etc. are subtleties not really key to natural selection). Does anyone else agree? — Axel147 17:51, 11 September 2006 (UTC)

Maybe there is a better example? Antibiotic resistance can be from mutations, phenotypic plasticity exists in genetically identical strains that acquire antibiotic resistance, a hindrance of cell division until the antibiotic environment stops is another mechanism, and HGT a growing and perhaps the major mechanism of antiobiotic resistance so I disagree it is a subtlety. There is not a bacterial genome to date not riddled with HGT sequence events. It is still natural selection- the reproductive success of insertion elements. Why not something like peppered moths, Darwin's finches has numerous examples of natural selection, Ectodysplasin Alleles in stickleback fish, insecticide resistance in drosophila populations, or maybe a yeast example. GetAgrippa 18:58, 11 September 2006 (UTC)

I didn't mean to play down HGT. I just didn't want to scare off the layperson. Maybe it should be mentioned additionally elsewhere in the article? But I don't think the organismic trait 'ability to receive insertion elements' is generally favourable for reproductive success. Insertion elements are preserved, I think, not just because of the reproductive advantage they confer on organisms in which they are housed; they are preserved (partly at least) because of their ability to jump. In other words this is no longer a clear cut example of natural selection acting at the level of the individual phenotype (of the organism). And as such not a clear example of natural selection as described in the opening paragraph? — Axel147 19:55, 11 September 2006 (UTC)

Aye, finches would be my pick. I wish I had time, but I don't. Best Regards, Pete.Hurd 19:30, 11 September 2006 (UTC)

My updates

I have updated my stored version to improve the introduction (see User:KimvdLinde/Natural selection. Feel free to use what you want. I do not care anymore about this article due to the continued fighting about definitions, but I did not want that my rewrite legacy at my own page was substandard. I will probably improve the defintion section of my own version as well by adding some operational definitions as used by specific disciplines (for example the 'differential reproduction of genotypes' definition as used by population genetisists). The current article is not featured article quality, it has a way to short lead section, the definition section is substandard, the additions to the antibiotic section are overkill, and there is a gross lack of appropriate references. The additions to the antibiotics example are true, but are better suited in the article about antibiotic resistance as the purpose of that section is solely to illustrate Natural selection to a general lay public, not to repeat how antibiotic resistance under all conditions arrises. If it ever reaches featured status, please update my list of articles on my user page to reflect that. -- Kim van der Linde ^{at venus} 03:22, 14 September 2006 (UTC)

I agree with your comments on my anal penchant for accuracy concerning the bacteria example. It is a occupational necessity. For that reason I have decided to only edit and write concerns in discusion and never write or directly modify an article. I forget it needs to be a simple encyclopedia. The old adage "Keep it simple stupid" needs to be my personal mantra. I believe like AdamRetchless that expertise is a hindrance to writing a simple, balanced, and informative article. You seemed to be angered over the situation. I hope I have not contributed to that.GetAgrippa 11:59, 14 September 2006 (UTC)

I think most have missed my point in the addition. I was trying to indicate how in the prokaryote world and in plants to some degree that HGT is probably more a source of evolutionary change than mutations. I think mutations are often emphasized too much and fails to recognize the growing contributions from other sources that comparative genomics is demonstrating in all life. GetAgrippa 12:06, 14 September 2006 (UTC)

Ho, stop, take it easy. You do not have to appologize. This is how article development goes, and it was just my thoughts that I expressed (a bit to harsh, my applogies). My frustration is with wikipedia as a whole, the anti-expert atmosphere, the POV-pushers, and the increadable amount of time that you sometimes have to spend to get something fixed. The page was a declared disaster in the past and it was only resolved by me rewriting the page together with Gleng in my userspace. Since then, it has been relative stable. I have always been someone who tries to write for lay people. It is a challenge, but one that I think academics can benifit greatly from if they can master that. I always step back, and ask myself if my mother would understand this (if she could read English). She is not stupid, but uneducated, and it is at times for me a challange to explain her things that I do for work. If anyting at all, before you can write something complex in a simple way, you have to know every detail of your system, and most people do not.

As for leaving, unless there are some good changes in that it becomes much easier to correct POV-pushing and things alike, and in which pages can be concerved and only changed by experts who know where they are talking about, I might come back. But the atmophere here at WP is way to anti-expert, and even when you have written something, it just gets slowly demolished by passer-by's who think they know more than an expert on the details of complex concepts like natural selection. -- Kim van der Linde ^{at venus} 13:56, 14 September 2006 (UTC)

I agree with the anti-expert comment to a degree. It reminds me of teaching an introductory biology course (which I haven't done in years as I have been primarily research). You often present information that you know is not exactly correct or upto date. Such is the nature of the beast as most text are out of date in some areas. I like your comment of would your mother get it. In that regard, would an adolescent get it also. Maybe every article should be divided by age or maturity, so one section would be simple enough for children and another complicated enough for a college student. GetAgrippa 14:39, 14 September 2006 (UTC)

What I always try, and I think this is general practise, is to start with a lead that is general, and if possible, understandable by a large number of people. That has resulted in the current, slightly incorrect lead. The lead rewrite of my preserved version is a first atempt to fix that. It is not yet perfect, but the thinking process is going again. After that, you build up in complexity. Many people do not realise how complex the concept of NatSel actually is, and that is why I (better Gleng and I) have choosen to use an example (which allows you to leave out many of the mind-numbing details) instead of trying to explain the whole concept conceptually correct to a general public. If you look aroudn at the internet, and even in text books, this is how it is done often, precisely because of the complexity of the concept. After having satisfied the general public, the article can run free in complexity. -- Kim van der Linde ^{at venus} 14:53, 14 September 2006 (UTC)

Good advice!!!! GetAgrippa 15:01, 14 September 2006 (UTC)

I think KimLinde is slightly disingenuous in saying she doesn't care about the article due to fighting over definitions. I think she is pushing a slight POV on this and is happy as long as the article is her way. Why (if she knows her stuff) does she say 'Phenotypic selection is a term I never heard yet beyond Endler' and then a few weeks later provide a crucial extract from Lande with the sentence 'Animal and plant breeders routinely distinguish phenotypic selection from evolutionary response to selection (Mayo 1980, Falconer 1981).'?

Sober (who I previously granted as a backer of the phenotypic view) now seems happy with the conventional definition. Sober and Wilson, Unto Others 1998: 'The process of natural selection requires three basic ingredients: (a) phenotypic variation among units, (b) heritability, and (c) differences in survival and reproduction that correlate with phenotypic differences.' — Axel147 15:54, 14 September 2006 (UTC)

Whatever. You had the chance for many weeks to rewrite the horrible article that it was at that time (I even invited you explicitly), but you never did. Finally I did it and it seem to stand solidly until now. Feel free to change it to fit your definition, that is the nature of wikpedia. I have my own conserved version for people who ask me about NatSel. -- Kim van der Linde ^{at venus} 16:08, 14 September 2006 (UTC)

I am not familiar with your discussion. I tried to make a point with the bacterial example, but decided to drop it and removed it. Don't even get me started on the Natural Selection or Evoluton articles. I have decided to avoid these articles, because most comments go on deaf ears despite providing literature to support a point. It would be interesting to have Ernst or Gould if they were alive, or Dawkins to comment on the articles. I doubt there critiques would be welcomed either. However, their arguments shouldn't be welcomed because of their strong POV. It is better to let the article evolve and would probably best be written by someone who has never even heard of either topic. GetAgrippa 16:11, 14 September 2006 (UTC)

It was a very long discussion, see the archives. It has worn me out, and it is part of the reason for me to leave wikipedia. I do not need to get sneers like if she knows her stuff. And to answer that question of Axel: I shared an office with Lande in the past and discussed a lot of these thinsg with him (and other for that matter); Futuyama does not use that term; and I only digged up the exact quote when I really needed it. -- Kim van der Linde ^{at venus} 16:24, 14 September 2006 (UTC)

Omission

There is no mention of what the selection pressures are. I thought it is the fact that organisms tend to expand in size, putting a selection pressure due to an unchanged amount of food.—The preceding unsigned comment was added by 86.20.185.217 (talk • contribs) 18:41, 4 October 2006 (UTC)

Picture

The picture of the peacock contradicts the peacock article which states in the gallery "The White Peacock is frequently mistaken for an albino, but it is a colour variety of Indian Blue Peacock"

The file name has it as an albino. - Samsara (talk • contribs) 21:43, 10 October 2006 (UTC)

Just a theory

It does not state anywhere in the article that this is just a theory and that it has never been proven. That is why I put the weasel word tempelate on it. Everything in the article speaks as if all this is fact and proven when it really has not been proven yet. 69.22.216.252 02:30, 5 November 2006 (UTC)

It isn't just a theory, whatever you mean by that. The scientific evidence for the scientific facts of natural selection are well presented in the article. It would appear that you have a mis-understanding of science - or are simply trying to push some religeous POV? Weasel tag goes as it's placement amounts to little more than vandalism. Vsmith 02:44, 5 November 2006 (UTC)

Actually there are a huge number of studies demonstrating natural selection, so natural selection is a fact. You could argue is it significant in evolution. There are a large number of studies correlating natural selection with evolution, however there are studies indicating other factors can come into play and/or evolution can be unpredictable.GetAgrippa 19:41, 10 November 2006 (UTC)

With all due respect, Vsmith and GA, you are allowing a nobody to waste our time. The article itself explains these things. I would say that any registered Wikipedia editor should have no qualms simply reverting nonsense edits from anonymous users who clearly have neither read nor understood the article itself. Let's save this talk page for talk among people who are serious and deserve to be taken seriously. For me, actually having read the article is an obvious minimum standard. Slrubenstein | Talk 13:42, 12 November 2006 (UTC)

Natural selection is a theoretical deduction of perceived evolutionary changes in species.

We must, however, remember that correlation does not imply causation. Moreover, the correlation evident between species does not specifically imply causation. And until natural selection, and more importantly, macroevolution can be proven in the laboratory, they will both remain theoretical.

Science is the pursuit of causes, both natural and unnatural [intelligent]. To completely disregard the possibility of intelligent causes is negligent. This article should not present this concept as if it were completely 100 percent proven. I fear no change will be made by the evidently biased authors/administrators of this article that are bent on making this science appear as if it has been fully observed. Remember, due to certain lapses in knowledge, even the scientific process makes certain presuppositions that requires philosophy/faith. Futuremore, we're not just primordial slime, meaning cannot be fomented through evolution.

Nothingness to Ameba to Brain through time, which only leads to entropy. Come on, every worldview is exclusive and closeminded.

Nope, it isn't just correlational, there's experimental and mechanistic support. Guettarda 20:53, 22 February 2007 (UTC)

Just from the use of "just a", it would be fair to dismiss this anonymous user. If it were a hypothesis, then perhaps yes. But that is not the case. I suggest that you pay a visit to TalkOrigins if you are unsure of terminology or the current standing of evolutionary theory.--THobern 12:50, 13 June 2007 (UTC)

rv - line "Who is Charles Darwin?"

( Who is Charles Darwin?) Appeared after a heading resulting in the heading not displaying correctly. The line seems meaningless so I removed it Paul Hjul 10:00, 5 December 2006 (UTC)

Lead Section

I think that the lead section is pretty good but needs to be simplified a bit.

---

Natural selection is the process by which individual organisms with favorable traits are more likely to survive and reproduce than those with unfavorable traits.

• not bad

In so far as there is genetic variability for the trait under selection, the genotypes associated with the favored traits will increase in frequency in the next generation.

• In so far???? genotype???? This sentence is too long.

Given enough time, this passive process results in adaptations and speciation (see evolution).

• not defined. One has to look these big words up which is not good for an introductory paragraph.

Natural selection is one of the cornerstones of modern biology. The term was introduced by Charles Darwin in his 1859 book The Origin of Species, by analogy with artificial selection, by which a farmer selects his breeding stock.

• pretty good, except I am not sure about the last phrase. I would reword "by which a farmer selects his breeding stock". Sounds too technical. I would make it simpler.--Filll 14:55, 13 December 2006 (UTC)

Yes, a sentence beginning 'in so far' seems to me to be at least as awkward as the one it replaced. And is it correct? Doesn't a genotype refer to the genetic makeup of the whole individual, not the units that might get passed on? And isn't this a probabilistic process, with no guarantee that favourable genes will increase? (And doesn't this presuppose somthing about mapping between genes and phenotypic trait: in cases of pleiotropy genes associated with favoured traits may NOT have a tendency to increase in frequency in the next generation — if they are also correlated with other unfavourable traits.) — Axel147 15:49, 13 December 2006 (UTC)

You are welcome to improve the wording. However, remember this is an introduction. There is no need to get bogged down in exceptions and nuances. At some level of simplification, the statements should be true (which they are). There is no way that you can write a few simple sentences that incorporate epistasis, cytoplasmic inheritance, genetic maternal effect, imprinting, balancing selection, drift, etc. Those topics can be discussed in the remainder of the article. Genetics411 16:44, 13 December 2006 (UTC)

Another nuance if you like is that you've removed the word heritable. Heritability is key. One problem is that it is possible for traits to have a genetic basis without being heritable. Another is that some authors prefer not to limit the concept of heritability to genetic mechanisms. So I'm not suggesting anything complex — just reverting to the original sentence I think (which I didn't write myself). But I'm interested to see what other people think... — Axel147 02:28, 14 December 2006 (UTC)

I understand that Wikipedia has different conventions than normal, so I may be way off. An introduction should serve three basic purposes:

1. It should serve as a summary of the field for people who will only read the introduction. It should give them an accurate "flavor" for the field, but not get bogged down in details or exceptions. It should be something that any intelligent reader of whatever (scientific) background can understand and come away feeling they know a little bit.
2. It should serve as a teaser for the main body of the article, to entice the reader to read more.
3. It should be true to the field so that experts don't automatically reject the entire thing. On the other hand, it should also be uncontroversial -- there is time for that later. This should also include a hint of criticism, if there is significant amounts.

Now, what is it that you want people to come away with if the introduction is the only thing they will read? Really, the original version was pretty bad. If nothing else, it uses heritable in two different ways in the same sentence, one of which is absolutely incorrect. Is the difference between genetic and heritable essential for an elementary understanding of natural selection? Is that how we want to spend valuable introduction space, particularly if it has to be spelled out for the non-expert? I am probably way off base for Wikipedia. My apologies. Genetics411 03:15, 14 December 2006 (UTC)

The criteria above are fine, I'm not disputing those. But the original sentence has received good consensus if you look through the history of this talk so I was wondering if it could be tweaked if you're not happy with it? How about 'It works on the whole individual, but only heritable traits will be passed on to the offspring, with the result that favorable heritable traits tend to become more common in the next generation' ? Anyway that would be my vote. — Axel147 04:34, 14 December 2006 (UTC)

Can we just introduce the first paragraph with the following sentence: "Natural selection is the process in which heritable characters which affect survival and reproductive success will be differentially propagated within a population of reproducing individuals" ? We could leave much of the present paragraph as an explanation of this succint definition. In modern treatises, natural selection is very much understood as the process of differential transmission of characters, rather than as the processes which affect the survival or reproductive success of individuals (and thereby cause differential character transmission). At the extreme, Dawkins define natural selection as "the process through which genes out-replicate each other", but we need not go there in an introduction.

I personally think the path of wisdom is to leave the first paragraph alone and improve the rest of the article, particularly with references. Samsara (talk • contribs) 13:07, 18 December 2006 (UTC)

Yeah, but you weren't arguing this before Genetics411 change. What makes 'heritable' jargon and 'genetic variability' not jargon? — Axel147 19:05, 18 December 2006 (UTC)

Evolution without natural selection

I began to write a section about the effects of natural selection not taking place, but I realized some of the examples I intended to use were natural selection. Here I'm talking about situations where natural selection has little impact on a trait due to it being of neutral fitness contribution. One example I planned to use was the eyes of moles - how they have diminished due to lack of use. Really it's more a case here of natural selection favoring the removal of the eye as 1) It can be infected by all the dirt and debris in the mole's environment, and to a lesser extent 2) Construction and maintenance of the organ uses up precious energy (here a much weaker force than that of infection, no doubt). However, even without these forces of natural selection favoring the absence of the eye, there is still the force of entropy which simply tends to favor randomness - general loss of orderly arrangement. Even without natural selection there is a tendency to break down progress made in a certain direction, so for example mutations of the eye that were not injurious in other ways would make no difference to the survival rate and hence the careful order of the eye would tend to break down over time without any selective forces acting on it.

(Another force I've neglected to mention is sexual selection, which would act as a backup against the forces of entropy because animals seldom choose partners with strange mutations, even if they aren't deleterious to the species).

I'll try to compose a better section when I have some time, hopefully with some more examples. Comments on the topic are most welcome. Richard001 09:39, 2 January 2007 (UTC)

Agree in principle, but please don't equate entropy with randomness: as the linked article states, "Spontaneous changes tend to smooth out differences in temperature, pressure, density, and chemical potential that may exist in a system, and entropy is thus a measure of how far this smoothing-out process has progressed." The "orderly arrangement" is part of a nineteenth century analogy attempting to visualise the motion of energetic molecules as "disorder", and is completely superseded by quantum mechanics. .. dave souza, talk 11:00, 2 January 2007 (UTC)

Be careful of introducing material the "seems" correct, but isn't. It turns out that in lab colonies of Drosophila, at least, there is mate selection favoring the oddballs. I have not looked for other examples of this phenomenon, so cannot say how common it is. Genetics411 15:10, 3 January 2007 (UTC)

I don't really agree in principle. By defintion this is not natural selection but evolution by another mechanism. I think it is better to cover this in the evolution page rather than here. — Axel147 13:21, 8 January 2007 (UTC)

Removed from the article

However, Stephen Wolfram claims to have shown simple rules of cellular automata create complex forms, which organisms evolve outwardly, filling all the possible forms available to them by the initial rule set. Natural selection then becomes both unnecessary and impossible for paring down evolution to robust forms. "Complexity is destiny—and Darwin becomes a footnote. "I've come to believe," says Wolfram, "that natural selection is not all that important." By showing this trend towards complexity in natural systems, Wolfram believes he has not only shown the limits of selection, but also that complexity and order both can both appear in natural systems as a simple matter of reproduction with no other influences.

I've removed the preceding passage from the article because of undue weight; it is represents a tiny minority view. Wolfram's ANKOS (A New Kind Of Science) has not been well received in the scientific community at all: [http://www.math.usf.edu/~eclark/ANKOS_reviews.html A Collection of Reviews of ANKOS and Links to Related Work]. FeloniousMonk 17:04, 14 January 2007 (UTC)

It was added again. I have removed it, again. The Times review on 20 May 2002 puts this book in its proper perspective, "Cranks are an occupational hazard that every scientist eventually faces. Fortunately, these characters are usually easy to spot. If someone claims to have a grand theory that overturns centuries of scientific knowledge—especially when the theory spans unrelated fields like physics and biology and economics—the odds are good that he or she is a crank. If the author publishes not in standard scientific journals but in a book for general readers, watch out. And if the book is issued by the author rather than a conventional publisher, the case is pretty much airtight." Since the peer review didn't occur before publication, we'll have to see how it fares after publication. Genetics411 01:36, 20 January 2007 (UTC)

Gene flow effects on speciation

"The evolutionary process of divergence, which ultimately leads to the generation of new species, is thought to occur usually without any gene exchange between the diverging populations. However, until the recent growth of multi-locus datasets, and the development of new population genetic methods, it has been very difficult to assess whether or not closely related species have, or have not, exchanged genes during their divergence. Several recent studies have found significant signals of gene flow during species formation, calling into question the conventional wisdom that gene flow is absent during speciation."Curr Opin Genet Dev. 2006 Dec;16(6):592-6. Epub 2006 Oct 19. Recent advances in assessing gene flow between diverging populations and species.Hey J. Further while I agree gene flow is homogenizing, it can be useful as gene loss is significant in many examples of speciation and HGT and Hybridization can rejuvenate a genome and generate novelty and speciation. The last year has been a boom for HGT and hybridization studies. I guess we need to address this for NPOV. GetAgrippa 20:46, 15 January 2007 (UTC)

Information Theory

Before you remove Wolfram again, be aware that there is a 3 revert rule in effect. Enough of the nonsense that Wolfram hasn't been peer reviewed for he has been and I've provided the link. Furthermore, though his views might not be popular with some biologists, his views are popular in other circles (bioinformatics for example). Also recall that the views of Darwin himself, have not been popular in the past. If you can show that Wolfram has been misquoted, or that his views of natural selection have been proven wrong, you may remove my contribution under Information theory.

Why are Wolfram's views noteworthy and worthy of inclusion here? Wolfram's criticisms of Natural Selection are noteworthy because few other scientists have been successful in critiquing the problems with the theories of Natural Selection but he has not only exposed errors in the field (such as the ones he showed about Stephen Jay Gould's work), but he has also presented a fairly detailed criticism of natural selection which has to date gone unanswered. It possible Wolfram's views go furthest in finding the weakness with natural selection, but his counter suggestion, shows that complexity and diversity arise by mechanisms other than natural selection and also make it possible to formulate abstract theories about evolution apart from natural selection! The only way this would not be worth noting in this article would be if Wolfram was wrong, or if there is more incentive to hold old ideas rather than adopt new.

He notes that traditional mathematical models have never even come close to capturing the kind of complexity found in biological systems, as a result biologists have treated evolution through natural selection as the foundation of this complexity. He notes that the theory of natural selection has implied complexity in biological systems, but has never actually showed exactly how natural selection requires it. This is a very significant criticism indeed, and if true more than noteworthy except by some who do not welcome debate. Searching the literature of the field - I think his criticism holds, and certainly no biologists has responded.

True. Wolfram's mathematical views of complexity have been criticized. Specifically his theory of the Equivalence of Computational Complexity have met with the most resistance and debate, but that does not undermine in any way his response to natural selection, and for this reason, I have restored his criticism. WikiRat1 17:23, 20 January 2007 (UTC)

The place you have put this is inappropriate for the material, even if it is true. You have completely swamped a section on information theory with criticism of natural selection in general. Genetics411 17:30, 20 January 2007 (UTC)

Ok. I don't object to that, but instead of removing it, put it where you want it to go. It looks like you are trying to censor Wolfram's views, and I'm sure that isn't your purpose. WikiRat1 17:39, 20 January 2007 (UTC)

Complexity is not the primary focus of natural selection, and Wolfram's "opinion" is obviously a controversial fringe idea at present as well as appearing to be essentially off-topic. An uncritical account of his assertion has ho place here: it appears to be notable enough to justify an article on its own, which could be briefly mentioned and linked from here. .. dave souza, talk 17:55, 20 January 2007 (UTC)

Wolfram has published in respected journals in Particle Physics, General Physics, Cosmology, Mathematics, Computer Science, Computational Theory, Complexity Theory, and Technical Computing. How exactly is Wolfram fringe? His Work

In examining Complexity (an topic that interests him) Wolfram has undermined all of Natural Selection. In examining a part, he has undermined the entire theory. Complexity might not be of interest to this article, but the integrity of the theory itself might be.

WikiRat1 18:08, 20 January 2007 (UTC)

<reduce indent> He's hardly undermined the theory – he appears to have shown a possible source of variation for natural selection to act on. Try writing an article that covers his ideas on their own, citing relevant critiques. .. dave souza, talk 18:30, 20 January 2007 (UTC)

Look this is all debate about the idea - which shows its significance. If it is true that adherence to simple rules can result in diversity, than "Natural Selection" is unnecessary. He says as much.

Regardless of whether or not you believe Wolfram, his criticism is levelled clearly at Natural Selection and therefore belongs here. If you disagree, ask for third opinions and take this to arbitration. Personally, I would think that any valid suggestion that Natural Selection is wrong would be worthy of attention.

He does not present his views of Natural Selection as their own theory, rather he presents them as explanations for the exact same observations that Natural Selection is an explanation for. He clearly articulates his criticisms, as well as a counter explanations. To date it is the most sever criticism natural selection has faced. His work includes a review of the work of some of the big names in this field (I mention Stephen Jay Gould for example who was shown by Wolfram to be wrong) and not only exposed errors in their work on Natural Selection, but showed problems with their conclusions.

It may be too early to see what will come of Wolframs views, but it not too early to recognize his criticism for what they are. I cannot understand why, if natural selection is valid, this article cannot include 3 paragraphs on its criticisms. If the criticism itself is weak and Wolfram wrong, don't censor it, let Wolfram's opponents do that. However, these criticisms, and its originator are credible peer reviewed scientists, and noteworthy WRT this topic.

WikiRat1 19:01, 20 January 2007 (UTC)

You're presenting a brief quote from a popular book taken out of context, and adding to this a great deal of your own opinion that this is a noteworthy criticism of the tenets of natural selection. This looks very much like original research. How does it bear on organisms being fitted to their environment? A mathematical explanation of complexity arising from simple sources overcomes a common objection to natural selection rather than overthrowing its tenets – if "complexity and order both can both appear in natural systems as a simple matter of reproduction with no other influences", that provides the variation for selection. However his mathematics also appear to need a great deal of work to become generally useful in the field – your statements imply that it's unused. What you call "his competing explanation of diversity through simple rules" could some day provide useful support and development of natural selection theory, but we need to see your assertion being made by reliable sources and not just your interpretation of his theory of everything. ... dave souza, talk 20:17, 20 January 2007 (UTC)

Mathematical approaches to biological systems is a daunting task. For every rule in biology there is always an exception. While I agree with self replicating systems and mathematical derived complexity that in no way invalidates biological natural selection. Creating mathematical models using simple rules may mimick natural selection, but does not begin to approach the complexity of nature in the process of natural selection or evolution by natural selection. Cooperation as a principal also leads to complexity and diversity. GetAgrippa 20:40, 20 January 2007 (UTC)

Umm, dave souza have you read Wolfram's criticisms yourself? Or peoples response to it? I suggest you do so before "accusing me of taking a brief quote out of context". He makes all of his work available on line here and his views are hardly brief, or lacking in justification. Futhermore, I agree that it is "original research", but it is Wolfram. Since I am not Wolfram, I should be permitted to present his ideas. I suspect we all agree that Wolfram is controversial, but it is not his theory of Computational Equivalence that I am adding - that would be too much. Rather it is rejection of Natural Selection I am adding.

How about we try this theory instead - his views contradict the popular notion in Natural Selection is solely responsible for the survival of traits and genetic diversity - instead he argues that living things are capable of self organization. Now this isn't a pseudo science - its testable assertion. Because this notion refutes natural selection should it be censored? Is this some type dogmatic issued Wolfram is arrogant or people find the debate is objectionable?

There is a bigger debate going on, not about Natural Selection, but about Bioinformatics vs Biology, and I would argue that Wolfram is not the issue. For example check out Lila Kari's work which is suggestive of natures ability to solve problems uninfluenced. Here is a computer scientist who has shown that virii adhere to known computer science laws on compression, or who has shown the ability for DNA to solve problems. Lila Kari's work may not be advocating as Wolfram does, that natural systems are equivalent to computations, however her work is influencing biologists as well as bioinformaticists. In fact her work amongst others is contributing this paradigm shift I apparently am being denied the right to mention. These views of Wolfram's that I've presented apply only to Natural Selection, though they are reflective of this larger debate. WikiRat1 22:06, 20 January 2007 (UTC)

Interesting link, having read a bit before it demanded I register it looks pretty clear that Wolfram accepts and agrees with natural selection, but rejects misunderstandings about how it relates to complexity and the production of optimal solutions. Please show exactly where you think he rejects natural selection, with page number and preferably an adequate citation. Guess I'll try registering. Grr. .. dave souza, talk 22:41, 20 January 2007 (UTC)

A lot of articles on hybridization the last year seem to indicate the ability to generate diverse phenotypes adaptive to extreme environments, often the hybrids will survive in environments nothing like either parent species. Variation proposes and nature still disposes, but the novel variation from seemingly nowhere with no phenotypic history in either parent is fascinating. That is the problem with mathematical models mimicking nature by simple rules because nature will always change the rules.GetAgrippa 23:02, 20 January 2007 (UTC)

Has Wolfram published in biological journals more appropriate for the topic? Not much of a debate when you don't invite evolutionary biologist in peer review. Natural selection does not mean evolution. You have evolution by natural selection. Even if natural selection were proven completely in error (which it hasn't plenty of examples in nature) it does not disprove evolution and it would probably be replaced by a more comprehensive or refined mechanism that would deal with the complex multifaceted nature of biological systems. " Natural Selection is solely responsible for the survival of traits and genetic diversity - instead he argues that living things are capable of self organization." Self organization is already dealt with in the article. Natural selection is not solely responsible for the survival of traits or genetic diversity-facial patterns in humans is due to genetic drift and are completely neutral. GetAgrippa 00:20, 21 January 2007 (UTC)

I think anything more than a sentence on Wolfram's work in this article would be WP:Undue weight. At most, I think a link to A new kind of science, and the coverage of the debates over the merit and implications of the work on that page, accurately reflects, to overemphasizes, the perceived importance of that work to this topic by practitioners in the field. Pete.Hurd 00:51, 21 January 2007 (UTC)

Some Citations

dave souza, alright, this seems kind of desperate (for me to post a bunch of page numbers), but at your request here are some citations which you can check out yourself …

p.14 “Evolution Theory. The Darwinian theory of evolution by natural selection is often assumed to explain the complexity we see in biological systems – and in fact in recent years the theory has increasingly been applied outside of biology. But it has never been at all clear just why this theory should imply that complexity is generated. And indeed I will argue in this book that in many respects it tends to oppose complexity.…..”

p.383 – 432. Most of Chapter 8 starting with Fundamental Issues in Biology showing something other than Natural Selection as responsible for adaptations.

p.383 “… And in fact what I have come to believe is that many of the obvious examples of complexity in biological systems actually have very little to do with adaptation or natural selection. And instead ….”

p.391-392 “ … So why should this be? My guess is that in essence it reflects limitations associated with the process of natural selection. For while natural selection is often touted as a force of almost arbitrary power, I have increasingly come to believe that in fact its power is remarkably limited. And indeed, what I suspect is that in the end natural selection can only operate in a meaningful way on systems or parts of systems whose behaviour is in some sense quite simple. …”

He goes on to justify his belief natural selection is a force of limited power into the next pages arguing that natural selection is not sufficient to produce complexity we see in nature.

p.393 “In a sense it is not surprising that natural selection can achieve little when confronted with complex behaviour. ….”

“It has often been claimed that natural selection is what makes systems in biology able to exhibit so much more complexity than systems that we explicitly construct in engineering. But my strong suspicion is that in fact that main effect of natural selection is exactly the opposite: it tends to make biological systems avoid complexity and be more like systems in engineering.”

p.397 Criticism of Natural selection as a predictive theory … p.400 Constructing growing plants by means other than natural selection … p.402-404 Constructing the shape of leaves by means other than natural selection … p.408-410 Constructing the arrangement of leaves by means other than natural selection .. p. 411 Constructing plant geometries by means other than natural selection … p.414-417 Constructing the Shape of Shells by means other than natural selection …

Just a comment on Wolfram’s views of Biological Evolution found on p. 414-417: It was Stephen Jay Gould who argued in his doctoral thesis on shells that natural selection is necessary to pare down the evolution of thousands of potential shell shapes in the world to only about the half dozen that actually exist in shell forms. He used this as evidence of natural selection. In these 3 pages Wolfram proves mathematically that in fact there are only six possible shell shapes possible in the world, and all of them exist proving Gould wrong.

p.423-425 Constructing pigment patterns by means other than natural selection …

p.842 when a process repeatedly makes random modifications and then applies natural selection, only fairly simple aspects are yielded (i.e. diversity does not result).

p.861 Natural Selection is identified as the basis of many phenomena in biology …. But biology still continues to concentrate on very specific observations with no serious theoretical discussion on complexity.

You can see his above comment to be true by witnessing the resistance being applied to including a single criticism of Natural Selection in this article.

p.1001 In the history of Natural Selection (Fundamental Issues of Biology) Wolfram comments that continuing controversies with religious accounts of creation have caused biologist’s to adamantly refuse to consider anything other than natural selection in shaping biological systems.

We don’t see a touch of that here do we?

p.1001 cont. In the late 1980’s natural selection had become firmly enshrined as a force of practically unbounded power, assumed-through without specific evidence to be capable of solving almost any problem and producing almost any degree of complexity.

This sounds like it might be noteworthy in this article. A credible scientist placing limits on the value of a theory.

p.1002 Genetic programs: “… there is no uniform correspondence between sophistication of organism and length of genetic program …”

Ok he’s not directly criticising natural selection here, but its deficiency is implied.

p.1002 Natural Selection section suggests that more work needs to be done to map out the exact limits of the usefulness of the theory of natural selection.

p.1104 Growth in plants section asserts that diversity in plant growth patterns in best explained by rules (not natural selection)

p.1104 Branch patterns in plants suggests the same ….. p.1007 Shape of Cells, Symmetries in Nature, Isotropic growth …… p.1008 Shape of Antlers also ….. p.1008 Shapes of shells suggests the same again … p.1009 Embryonic Development …. p.1011 Growth of Tumours, Pollen, Animal Behaviour … p.1012 Pigmentation patterns does too …. Etc. through for hundreds of pages (not all dealing with natural selection)

1185 Molecular Biology: … DNA as biological artifacts having very simple origins .. (Same with some animals traits such as the mollusc shell, or the radiolarian skeletons etc)

I’ve provided at least some evidence that Wolfram is not glossing over natural selection. To be fair he is equally rigourous with other fields. Clearly, he was critically examining natural selection - and this makes his views pertinant. My point again, is that a credible scientist has raised criticisms about the value of, and placed limits on the subject of this article. Reading it over the not a single critical viewpoint is included. This is either because natural selection is beyond criticism or their are none. I don't know about the former, but I do now about the latter. So I suggest at least let us include Wolfram’s view as being possibly the only valid criticism raise so far.WikiRat1 03:48, 21 January 2007 (UTC)

Pages in what? Mathematical principals apply to biological systems because of physical laws-like the law of laplace in blood vessels or Murray's law in dividing blood vessels. I don't see that providing other possible mechanisms PROVES natural selection is wrong. It only proves that mathematical models can mimick natural selection. Of course work needs to be done in natural selection that is why the thirty year study of Darwin's finches showed evolution was unpredictable. Constructing pigment patterns is not based on mathematics but genetics and environment-phenotype. To say there is more than one way to achieve an end does not demonstrate which path is for real. Nothing against his work but I don't see that is appropriate for a encyclopedia article. As you state they are his views which is POV, and just cause a mathematical model can mimic natural selection it in no way proof of its existence or significance. There are numerous models for all kinds of biological phenomena just cause they may work does not prove significance. Has he designed experiments to test his hypotheses or is it just theoretical? I too have pushed lesser know areas of interest to be added to this article, but it is an encyclopedia and it just doesn't add to the subject so I backed off. Besides there are plenty of examples of the influence of the environment on developmental and phenotypic plasticity and stress induced mutagenesis. The influence of the environment on the development and life cycle of about every form of life you can think of has been demonstrated so it is difficult to deny the impact of the environment on molding life. Further complex behavior such that competition, predator-prey, etc. add another dimension of environmental influence. There is significance evidence to indicate that environmental change has influenced the tempo of evolution and speciation. GetAgrippa 04:49, 21 January 2007 (UTC)

This seems to be very much a strawman argument against alleged claims that natural selection creates complexity, rather than disputing fundamental tenets. There appear to be no such claims in this article. Wolfram’s view of natural selection promoting repeatable simplicity rather than maximum mathematical complexity, thus producing relatively simple engineering style contrivances, fits well with homology. Similarly his view that variability and complexity is greatest in features not subject to selective pressure accords with the theory as I understand it. Gould does not seem to be mentioned in the book, and in any case it would hardly be astonishing if modern computer based studies found flaws in work that Gould presumably did before 1967. Wolfram’s text is repeatedly qualified by terms such as "what I suspect" and "seems likely" – when Wolfram or someone using his approach produces peer reviewed papers on biology giving detailed clarification of these vague opinions, then the work will merit appropriate treatment in this overview of natural selection. However a balanced article incorporating Wolfram’s ideas together with relevant assessment or criticism could make a useful main article which could be linked from the Information theory section, and allow a suitably brief summary style mention here. .. dave souza, talk 10:27, 21 January 2007 (UTC)

Good call Dave, the article does belong in an Information theory article. Wolfram uses POV language in his book from what you were saying. Further Natural selection is said to encourage adaptive evolution not complexity. GetAgrippa 14:51, 21 January 2007 (UTC)

Just to clarify, I was thinking of an article about Information theory and evolution or something on these lines, to include more than Wolfram’s contribution. However that may be too closely associated with Information Theory and Creationism which isn't the aim, so the title needs some thought. .. dave souza, talk 18:25, 21 January 2007 (UTC)

I endorse Dave souza's suggestion of a "a suitably brief summary style mention" (I suggest c1 sentence) to link to another article (I suggest linking to A new kind of science, in the absence of an Information theory and evolution article, should such article come to be, then redir then, but I don't think a specific article needs to be created if the essence of the material exist in the A new kind of science article). Also note that GetAgrippa is correct in pointing out that there's nothing inherent in Nat Sel leading to greater complexity. Pete.Hurd 19:17, 21 January 2007 (UTC)

NPOV

I've put in NPOV until this issue is resolved. I recognize that the NPOV policy states that minority opinion doesn't necessarily have to be included in an article, but in this case there are no other views being represent which are critical of natural selection, and few others have gone into their criticism as deeply as Wolfram.

The NPOV policy does permit the minority opinion to be included when it provides balance, which I believe it does. Since the only critical view of natural selection is the minority position, it should be included. WikiRat1 04:05, 21 January 2007 (UTC)

Please don't remove the NPOV tag. You have other methods by which you can disagree.WikiRat1 04:07, 21 January 2007 (UTC)

I think it's pretty clear that Wolfram's views represent something less than what WP:NPOV calls "a significant minority" and is a lot closer to "an extremely small (or vastly limited) minority". Anything more than a sentence would be pushing your POV by WP:Undue_weight. Pete.Hurd 04:30, 21 January 2007 (UTC)

Wolfram's view represents one critical of Natural Selection. This article does not contain anything critical of the subject in question, therefore is biased. I'd be happy to research and include other scientists critical of Natural Selection if you'd care to point them out. Otherwise, in the interest of fairness, I think that unless you have specific scholars who refute Wolfram's view of diversity in nature or you can show how somehow Wolfram doesn't have anything meaningful to say on the matter I am restoring the NPOV tag until we can resolve the issue of bias in this article in a reasoned way. WikiRat1 06:43, 23 January 2007 (UTC)

Also, GetAgrippa If you want to deny me the right to raise Wolfram as a critic of Natural Selection in the interest of fairness, you don't go about it by disagreeing with Wolfram. You go about it by showing that either he isn't actually critical of the subject, or that I am misquoting him, or that his opinion isn't relative to the subject. I don't think you have done any of that. Your problem seems to be with the fact he is not a biologists, or you seem to disagree with his view of the source of diversity in living systems. Your disagreement with Wolfram isn't enough to deny me the right to include him here. You may disagree with him, but you must also allow for opinions you may not endorse for the sake of objectivity.

However, I agree that Wolfram uses POV language in is work. This is one of his shortcomings, and is rather unfortunate, because many cannot get past his ego when they read him. Other criticisms of Wolfram include that he worked for 2 decades without consulting his scientific peers, but so did Newton, Kepler (and Einstein, but not for 2 decades). I suspect though that had Wolfram published less in his book and more in academia, reaction to him would not be so fierce. Nonetheless, he was able to do in his book what others were not (for example, one of that things that he was able to to show not related to the topic at hand was that a Turing Machine with only two states and five possible colours could be a Universal Turing Machine. For forty years Computer Scientists thought that a Universal Turing Machine had to be more complex .) Despite his ego, and other faults his opinion is valid, and his views merit and deal directly with the subject of this article. Although you may disagree with his arguments professionally, that isn't reason enough to prevent his mention here.WikiRat1 06:54, 23 January 2007 (UTC)

Due mention given as requested. This is a general article about a large and complex field, any further detail can go in a linked article as suggested. .. dave souza, talk 08:55, 23 January 2007 (UTC)

WikiRat you are confused. I never said you misquoted Wolfram another editor did. I don't have a problem with Wolfram. I think his work will be useful for biologist and evolution modeling. I just don't think his ego and POV and a mathematical model discredit over a hundred years of biologist in every field demonstrating natural selection in thousands of publications. Further he may be a brilliant mathematician, but he has not engaged biologist or evolutionary biologist in peer review to debate the merits of his ideas or in a step wise fashion dismiss ALL the published evidence of natural selection. He has been mentioned in the article in an appropriate place and in context. GetAgrippa 14:35, 23 January 2007 (UTC)

I haven't read much of Wolfram I admit, but from quotes above he only says things such as "my guess is that ... it reflects limitations associated with the process of natural selection" and "my strong suspicion is that in fact that main effect of natural selection is exactly the opposite: it tends to make biological systems avoid complexity...". That on the face of it sounds like conjecture so is it supported by theory or evidence? Wolfram seems to claim he has a better way of looking at things: one which may provide more insight and additional explanation of functional design. This in itself does not undermine natural selection, and may happily co-exist with it. Whereas other times Wolfram seems to claim natural selection is oversold? At the moment I think there's insufficent weight. — Axel147 15:58, 23 January 2007 (UTC)

GetAgrippa, sorry you're right, it was another editor not you. I apologize for accusing you wrongfully. About his POV, I wouldn't say that it discredits natural selection. I've stated already that he accepts natural selection, but insists it has limited effect. What his POV does is provide a contradictory explanations for the evolution of individual traits in species, and a view of the differentiation of the species themselves that has exactly the opposite effect of natural selection (sort of natural selection on its head). I think that this is interesting. Assuming that the long term consequence of posing an alternative to natural selection as we know it now, is that we re-examine all of the processes we attribute to natural selection, some will no doubt remain clear evidence, while others may fall away, and instead be understood in terms of Wolfram's process. (I am assuming of course that he has indeed hit upon a valid evolutionary process, and that it is exactly as he describes it. I'm also assuming it's role in nature is opposite to natural selection since his process builds up rather than eliminates). WikiRat1 23:01, 23 January 2007 (UTC)

Well ok, but can you help out those who don't know much about this. How does Wolfram's process generate complexity? — Axel147 01:55, 24 January 2007 (UTC)

Wolfram studies complexity. In fact he practically invented complexity theory. What he was looking at was the assumption that complex things must have complex underpinnings (his first contributions were in particle physics and lord knows, particle physics is complex!). However, when he got looking at finite automata, which are really very simple basic machines, that don't do a whole lot other than obey a few simple deterministic rules, he happened across Rule 30 which was an automata that produced random, but structured unpredictable patterns such as the ones found in Conus and Cymbiola genus. As a mathematician, a physicist and as a computer scientist this screamed out a problem. How can a deterministic process, with absolutely simple initial conditions produce randomness and complexity. Rule 30 started out with 1 single black cell and 8 simple rules. Deterministic process are SUPPOSE to produce deterministic behaviour, and non-deterministic systems are SUPPOSE to produce non-deterministic behaviours. At least this is what we seem to see in nature. Also chaos theory says that although some systems have a sensitive dependence upon initial conditions, those systems almost always have complex initial conditions. But his automaton was 1 dimensional, with no simpler initial conditions than a single black cell and 8 rules. This lead him to discover that even simple conditions, with few rules can create unbelievable amounts of diversity/complexity. In fact the threshold for complexity didn't even seem to be that low (i.e. when he made more complex initial conditions, with more complex rules, he didn't see any greater complex behaviour.

Back to Natural Selection: Ok so all of this pretty much explains what he is on about, but how does it apply to living systems? Well if you compare this to the assumptions in natural selection, we assume that many more forms are possible in nature from one evolutionary step to another. Only those forms robust enough to survive do so, because selection eliminates the rest. However, in the specific examples that Wolfram has looked at (such as the shape of shells) ALL of the forms that are possible (mathematically at least) ARE STILL evident today, and in fact natural selection hasn't weeded any of them out at all. (Of course someone should look at his proof that only 6 basic forms of shells are possible in nature to confirm it is correct ....) In the case of shells this completely contradicts Stephen Jay Gould's work who argues thousands more are possible, but we only see six. Wolfram has also looked at antlers, branch patterns, plant configurations, the shape of cells, and a number of other things etc. Now this doesn't quite rule out natural selection, but in the examples he looks at he notes that the impact of natural selection environmentally has only ever been superficial, i.e. it may change the chirality of the shell for example, but it doesn't change the shape of the shell. All possible shell shapes are being expressed. Natural selection then has had some impact however some simpler (possibly not yet understood) biological process has been responsible for the overall expressions of diversity by establishing the rules by which evolution is taking place (again biologically), based upon some simple initial condition. Furthermore the initial conditions that have set the evolutionary path for some trait need not even be all that complex in order for complexity to occur and given time, all possible forms will be built (expressed) which means that we can presumably know both the simple rules, and the initial conditions (because they are simple). I suppose rather than "Natural Selection" you could call his view "Natural Expression".

I don't fully understand all of his arguments, but I hope this helps. WikiRat1 04:17, 24 January 2007 (UTC)

Thanks, that does help. But Wolfram must accept all of the things don't exist all of the time. This seems especially true for (more complex) properties which seemingly vary continuously and appear to have a very large number of options. I'm thinking shell colour, size or strength and the interaction of these. There must be some way of knowing which of these theoretical possibilities are "selected" or "expressed" and I'm not sure Wolfram is giving us any. Is Wolfram saying all 6 shell forms must exist: that it is not possible for any one of these to become extinct? — Axel147 14:26, 24 January 2007 (UTC)

Complexity seems a somewhat subjective term. I see the bacteria or yeast as extremely complex. The thickness of shells is determined by environmental cues-predation. Wolfram maybe on to something considering parallel and convergent evolution, that given certain molecular tools that only certain paths will be favored. It is difficult to discount the impact environment has on development and the life cycle of any organism. Does Wolfram just ignore these facts or does he eliminate the possiblity of environmental influence and go with a model of internal cues? It seems his model is in a vacuum. Cooperation is said to increase complexity-Novak. GetAgrippa 16:05, 24 January 2007 (UTC)

The respective roles of natural selection and self-organisation in the emergence of complexity.

Just a reply to all this talk about Wolfram, and self-organisation in general. It is a fact that rich, complex dynamics do arise "spontaneously" in certain systems, without any natural selection or evolution. It's called self-organisation, and it is not new. At any rate, it certainly doesn't make natural selection "unnecessary" to explain the complexity of living beings, because it does not explain adaptation. Under the proper conditions, brute matter will spontaneously create a range of diverse forms - but very, very few of them will result in anything useful. Complex, well-adapted organs cannot be explained by spontaneous assembly. Self-organisation makes it easier for natural selection to come up with complex designs, but does not replace it.

Complexity is not just the result of evolution by natural selection alone, or self-organisation alone. If there were no natural selection, adaptive complexity would be unheard of. If there were no self-organisation, then the amount of complexity available for evolution to "play" with would be vastly diminished; for example, building well-organised regulatory networks would be much more difficult without the "self-organising" properties of random boolean networks discovered by Stuart Kauffman.

In any case, I'm not sure this page is the place to mention these things. This is an article about natural selection, not about the emergence of complexity in nature. The respective roles of self-organisation and natural selection could be discussed in other pages. No? --Thomas Arelatensis 14:05, 26 January 2007 (UTC)

No doubt others will accuse Wolfram of rediscovering self-organisation as you have. Unfortunately our views as editors of Wikipedia is to ensure that balance, objectivity and neutrality all somehow influence the development of articles. Therefore, POVs are represented in articles that we, ourselves may agree with. Nonetheless for the sake of reflecting the current debates about things our own personal view points are not sufficient to exclude or otherwise monopolize content. In this case, you can the reaction to including Wolfram's views, and how animated it got. Similarly, a debate is festering between bioinformaticists and biologists on Wolframs views. Wolfram asserts that Natural Selection is unnecessary given his views views of complexity. Undoubtedly, some of his critics will put their disagreement to peer review, but I suggest that I am having a hard time finding any who have refuted him anything more than casually. Wolframs' views are certainly out in the open now, a list of references has been published above about his views dealing with natural selection, so that others may check out my claims about him (to ensure I am representing his view faithfully). Because Wolfram himself opposes the scope or power of Natural Selection, I can personally think of no better article to include his criticism (and as I pointed out above, does this article really contain any other valid criticisms about the subject?). I am glad you disagree with Wolfram. Perhaps it will motivate you to assist me in finding scholars who have examined his criticism. If you can find some scholarly sources accusing Wolfram of rediscovering self-organisation, or even better outright refuting his criticism of Natural Selection, could you kindly include it here also? WikiRat1 05:08, 2 February 2007 (UTC)

Have you examined these? Pete.Hurd 05:29, 2 February 2007 (UTC)

This Science article review was similar in tone:Science 4 October 2002: Vol. 298. no. 5591, pp. 65 - 68 DOING SCIENCE: Is the Universe a Universal Computer?A review by Melanie Mitchell*. In relation to Natural selection the review states: "Less compelling are Wolfram's speculations on natural selection. He contends that because the generation of complexity is so common in simple cellular automata, it must be common in nature as well and, therefore, natural selection is not needed to create complexity in biology. In his view, biological systems are complex merely because evolution has sampled a huge number of simple programs and these often give rise to complex behavior. Wolfram offers no convincing evidence for this claim, nor does he discuss where these programs are implemented--at the level of the genome? of cells? Although cellular automata provide plausible models of biological pigmentation and some aspects of morphology, there is as yet no compelling link between simple programs and complex biological systems such as the brain, the immune system, or cellular metabolism. On the contrary, it is increasingly clear that notions of selection and adaptation are crucial for understanding such systems."

The review gives the impression he tends to bloviate, he is dogmatic with narrow views discounting other concerns with weak arguments, and fails to provide few real advancements or real proof. Although they do say positive things that his research is useful. Just not grandiose as Wolfram suggests. I guess we need to add some kind of statement and references to detract from Wolfram's beliefs for NPOV. GetAgrippa 05:45, 3 February 2007 (UTC)

I don't know after reading more of these reviews. I don't think Wolfram's assertions about Natural selection are mature enough to pass muster as a valid concern. I am for keeping the Information theory section and its usefulness, but Wolfram's assertions are just his belief as he offers no real proof or detail just conjecture. At least we should drop his comments about Natural selection as they are not reliable or supported by secondary sources and really just constitute his orignal research. He offers no more proof than creationist arguments. GetAgrippa 13:32, 3 February 2007 (UTC)

I rewrote the Wolfram mention of natural selection but now it sounds idiotic. Any suggestions? GetAgrippa 16:21, 3 February 2007 (UTC)

Samsara noted in edit :"I like the previous one if it can be supported by a reference; what does it matter whether they are biologists, so long as their argument is sound?)" . I don't think it matters what his discipline is but it is not about a sound argument of his opinion but offering some description and some detail what he means and is there any proof to support his claims. It is a nebulous claim and others have noted that even as a hypothesis some aspects are untestable. I am deferring to the criticisms of others about his work. Pete Hurd found a useful site and I offered a Science article review of his book. I am not saying his mathematical model is incorrect in producing complex patterns, and I am just saying he offers an opinion that this could replace natural selection and offers nothing to support or substantiate or explain the statement. GetAgrippa 20:47, 3 February 2007 (UTC)

Axels edits seems to reflect he thinks it is red herring. Not that I'm putting words into his mouth. I think we could mention his work in reference to information theory without any mention of an egomaniacal rant about natural selection. Sound fair? Of course now if it is not related to Natural selection so why have it? Axel's argument appears to have merit. GetAgrippa 22:10, 3 February 2007 (UTC)

Fine by me the way it is, but "if it is not related to Natural selection [...] why have it?" yep, fine by me if the paragraph goes entirely. Pete.Hurd 00:09, 4 February 2007 (UTC)

I must admit I'm a bit confused (perhaps because I'm too lazy to read it all) whether Wolfram's ideas, if substantiated, challenge natural selection or whether they have little or no bearing on it. I see Wolfram's ideas and NS as alternative ways of explaining the complexity of life. If one is important, it seems to me the other would become less important. (Though NS explains more than just complexity.) But yes I do think it's a Red Herring and don't think Wolfram's arguments are fleshed out clearly enough. — Axel147 02:12, 5 February 2007 (UTC)

Axel I apologize for speaking in your behalf- putting words in your mouth, but it sounded like the voice of reason and I thought it was worth mentioning on the Talk. There is a disconnect between his idea as a mathematical model and biology-he doesn't propose where his ideas fit in, and he does propose a form of natural selection as he believes nature has selected through the possiblities to use simple programs to generate complexity. I think the Science review excerpt I posted says it well and is relatively complementary compared to those that Pete Hurd posted. Most appear to think his reference to natural selection was just an egomaniacal rant rather anything with substance. Wasn't there some mathematician who "proved" the existence of God by mathematical proof or model or discovery (or is it some academic legend). I don't know why that comes to mind. GetAgrippa 02:47, 5 February 2007 (UTC)

Response from Wolfram Science Group

Sorry to be a bit slow here, but when registering to look at the website I tactfully asked a couple of questions and forgot to check that mail account for a while, Here's the first response:

Comments:

> Does NKS reject natural selection,
No.
> or reject misunderstandings about the extent to which it creates complexity or produces optimal solutions?
Basically, yes.
Probably most important is that it suggests an actual mechanism for generating complexity in biology, that happens to have essentially nothing to do with natural selection. It also argues that finding "optimal solutions" probably has little to do with generating complexity.
For more information see:

http://www.wolframscience.com/nksonline/section-8.5

They helpfully sent a more detailed response:

Mr. Souza,

You asked "Does NKS reject natural selection, or reject misunderstandings about the extent to which it creates complexity or produces optimal solutions?" Definitely the second.

NKS knows that natural selection happens and is important, but doubts that it is fundamental to explaining the specific phenomenon of complexity in living organisms. First and most simply, complexity is more general than living organisms so its overall cause is unlikely to be a principle operating (for the most part or as originally meant) only within life. If dendritic drainage patterns or fracture patterns are complicated without having undergone millions of years of natural selection, vein systems may be complicated for entirely similar reasons etc.

Second, formal modeling shows iterative improvement schemes are excellent at "honing"a simple system by tweaking a small number of continuous variables toward some single optimum, but are lousy at finding global optima in a large space of discontinuous changes. On the other hand, point changes to simple programs rapidly explore a wide variety of formal behaviors, including as a matter of course some very complicated ones, on the output side.

The classic Darwinian formula says "descent with variation" is the input to natural selection. NKS sees that "with variation" as much more important than at least some biologists suppose, because it expects a wider range of phenomenal variations from readily imaginable changes to underlying programs, whether those are (simple protein) genetic or developmental or regulatory etc. Wolfram thinks that natural selection is more likely to produce optimizing simplicities than complexity. And overall, it more likely to operate as a "net winnower" of a possibility space explored by algorithmic variation of underlying biological programs, than as the driver of that variation in the first place.

None of which means natural selection isn't happening or isn't important. Just that specifically variety (the harder of the two claims) and complex morphologies (the easier one) do not require it as an explanation, and can be better accounted for by factors operating at the previous, "descent with variation" stage, in Darwin's formula.

To me this appears to account for bits of history like the Cambrian rather better than the usual accounts. Instead of imagining that a whole bunch of separate "niche attractors" arose and ramified in a tiny space of time, and were all filled, one need only imagine that a body-shape or development program innovation occurred, and systematic variation in elements of that program then rapidly "tried everything". Some "stuck", in natural selection terms, and some did not - as adequate rather than optimized. A long but slow period of optimization and winnowing then follows in the variety already formed - that would be natural selection working.

Others have since noted that the two explanations - niche optimality "pull" and algorithmic variety "push" - make different predictions about things like species variety distribution across latitudes. Native mutation rate is higher where temperature is higher. Little more seems to be needed to account for the greater variety seen in the tropics. Not anything like a proof, just a suggestive "fit data point". Analyzing point mutations is an obvious place to try to confirm the idea. E.g. can one make simple vs. complex seashell shadings vary from one to the other with a few point mutations, without any selective forces operating?

I hope this is interesting, and thanks for your interest and the question.

Sincerely,

Jason Cawley, Wolfram Research

Hope this helps, dave souza, talk 19:03, 20 February 2007 (UTC)

Example at the beginning?

Let's talk about something slightly more important than the degree to which we should massage Stephen Wolfram's ego, shall we?

I really dislike the placement of the example as the first section of this article, preceding even the 'general principles' section that would provide context and background. A long time ago, I moved it toward the end of the article, but I see it's drifted back again. I don't much like the section in general - it's written in a very simplistic, tutorial style more suited to a textbook than a reference work, and its placement at the beginning makes the article read like chapter 2 in 'introduction to evolutionary biology'. It doesn't make sense to me, from an encyclopedia perspective, to place the example of a phenomenon before the description of the phenomenon. The lead doesn't do that job either. I imagine it's there for 'accessibility' purposes, but without preceding discussion it's just a blob of text before you get to the actual article.

Does anyone have an objection to demoting it, or a good reason it should be where it is? Opabinia regalis 06:18, 7 February 2007 (UTC)

Your analysis is correct-the horse before the cart and the horses ass topic of the talk (just kidding). The example of Darwin's finches also precedes the antibiotic resistance example so it is a double whammy. It seems every time I read the intro it has changed lately. Like a yo-yo. One day it was theory then a process then a change. I have noted a big trend to make the evolution related articles more simple, which I guess is good for accessibility. I am concerned with tossing out correct nomenclature as "jargon" and reducing some concepts into one phrase. You are correct that many use encyclopedias as reference material so it is O.K. to be complicated (I have forgotten that). Many articles are incredibly technical and exact. GetAgrippa 14:18, 7 February 2007 (UTC)

I don't have any objection. (I think the original reason was that example was the best way of explaining it without diving into the detail.) As a separate point I'm always confused by the sentence "Natural selection can act on ... any aspect of the environment". Maybe I've pulled it out of context but could it be worded more clearly? — Axel147 17:58, 7 February 2007 (UTC)

OK, I moved the example below 'nomenclature and usage', which is below general principles but still high enough that it precedes some of the more detailed discussion below. I generally think of articles as closer to mini-reviews than to textbook chapters, though it's good to have people on the other side of that fence as well.

Axel, that sentence confused the hell out of me until I realized I was mentally connecting the clauses wrong. Is it better now? Opabinia regalis 02:42, 8 February 2007 (UTC)

That's what I was doing despite the comma. Better now! Thanks. — Axel147 13:07, 8 February 2007 (UTC)

Still not NPOV

Natural selection still does not have any criticism of the idea in it. There should at least be on paragraph near the bottom labelled criticism. Steven Wolfram is not the only critic. I have heard complaints such as Selection just reduces the genetic diversity in a population. Even if a criticism is wrong, if it common it deserves a mention. GB 10:03, 12 February 2007 (UTC)

However, it is not common, relative to the support. Undue weight applies. Adam Cuerden ^talk 10:49, 12 February 2007 (UTC)

The laws of thermodynamics also have their "critics" (namely the "free energy" enthusiasts), yet there is no "Criticism" section in the related articles. Similarly, not a word on "Einstein debunkers" in the Special Relativity article. --Thomas Arelatensis 13:45, 13 February 2007 (UTC)

By the way, of course selection reduces genetic diversity within a closed population (though it can also maintain it by enforcing a blance between different sub-populations), but it does not "just" do that. It does it asymmetrically, by retaining and propagating newly found, well-adapted characters. This allows for gradual accumulation of small (or even not-so-small) improvements, the secret of evolution's power. Mutation and speciation -> diversity, natural selection -> adaptation and improvement.

--Thomas Arelatensis 13:45, 13 February 2007 (UTC)

All the talk of Mutationism is that proposed by Thomas Morgan who dismissed natural selection as a minor process and he proposed mutations as the driving force for evolution. Of course mutations don't have to precede evolution, as epigenetic heritable change driven by the environment can isolate phenetically a species long before a genetic change and reproductive isolation (biological speciation). Also hybridization and HGT can promote speciation which is not mutation. GetAgrippa 17:26, 13 February 2007 (UTC)

Mutations are a driving force behind evolution, but I think natural selection is the driving force behind adaptive evolution. That seems to be the difference. — Axel147 14:39, 21 February 2007 (UTC)

resistance

Also the example of antibiotic resistance in golden staph is not that great an example. Much of antibiotic resistance in bacteria is the result of horizontal gene transfer between different bacteria, rather than by mutation. GB 10:03, 12 February 2007 (UTC)

I had added a section addressing that but I removed because it is just an example for an encyclopedia. I agree HGT is more significant than mutations in antibiotic resistance.GetAgrippa 11:47, 12 February 2007 (UTC)

How in the world is propagation of resistance (even with massive HGT) not an example of natural selection? You still have a perfect example of certain alleles out-competing others (sorry for going all Dawkinsian on you, but that's what natural selection is all about). It would fail to be an example of natural selection if the gene in question did not carry any advantage, or if its propagation was unrelated to this advantage (e.g. genetic drift). Surely nobody argues that this is the case in this particular instance! --Thomas Arelatensis 13:29, 13 February 2007 (UTC)

Reverts

Natural selection is certainly not a process; it is patently an unproven theory. Let us try to remove the strong POV slant in this article through consensus NOT through reverting good NPOV edits. And less proprietorial disputes please. Peter morrell 12:41, 23 February 2007 (UTC)

Natural selection is a process which can be directly observed whenever a creature with a genetic disorder dies as a result, or whenever antibiotic-resistant bacteria flourish. How can it be described as an "unproven theory"? It has repeatedly been observed to operate in the natural world! Indeed, we can even see it at work in elephant populations (tusks are disappearing due to ivory poachers) and fish populations (cod, IIRC: the big ones get caught, so the fish are getting smaller). What is all this, if NOT natural selection? --Robert Stevens 13:48, 23 February 2007 (UTC)

Natural selection is a process. This is the generally accepted viewpoint, as you may easily verify by opening any university biology textbook. The article as it stands is therefore NPOV (at least in this regard). You are trying to push a fringe viewpoint which has not garnered significant support within the field of biology: this is POV. This is why your edits are being reverted. Again, please compare with laws of thermodynamics or special relativity: you will find that the general viewpoint is represented, not the fringe viewpoint ("perpetual motion / free energy are feasible" or "time dilatation is bunk"). You may want to concentrate your efforts on the specific articles devoted to these fringe viewpoints (intelligent design, creationism, baraminology, etc.)--Thomas Arelatensis 14:05, 23 February 2007 (UTC)

I think you misunderstand...explain to me how natural selection is an OBSERVED phenomenon. I say it is an unproven theory and little more than that, and the corrections I made were much more NPOV than the paragraph I changed. Please explain why you think I am wrong and you are right. Evidence for selection...where is it? Not evidence for evolution and not assumptions and inferences...concrete evidence. It is at best scant and wholly based upon assumption. Please defend your position with argument and evidence. BTW I am NOT a creationist. thank you Peter morrell 15:18, 23 February 2007 (UTC)

You have just been given several examples. Why do you insist these are NOT examples of natural selection, and what else could they plausibly be? --Robert Stevens 16:51, 23 February 2007 (UTC)

they are not good enough examples and evidence of this type does not really support a theory of this magnitude. Think about it. The theory of natural selection is unproven because such scant evidence is not sufficient to sustain a theory that is then going to be used to explain how all life forms evolved. Really? The small magnitude of the evidence is out of all proportion to the use the theory is going to be put to. If it did not matter very much, and was of little consequence, then of course scant evidence would suffice. That is clearly not the case here. In any case, you are *assuming* in those examples that natural selection is what is happening...it could just be random chance. You have proved nothing. Please give some strong concrete evidence. So far you have supplied feeble observations and much inferred assumption or joining of dots. That simply will not do. I repeat, natural selection is little more than a theory and an unproven one at that. The paragraph I put in earlier was vastly superior and more neutral [NPOV] to the stuff that was there before because it is more factually accurate. Selection is a theory, not a process. Only when it is proven with concrete evidence will it become a fully confirmed idea and thus be a process in the world. Until that point, it remains a theory. Can you please respond? thank you Peter morrell 17:08, 23 February 2007 (UTC)

You seem to be confusing "natural selection" with the Theory of Evolution. Natural selection, like mutation, is an obvious and empirically-verified process. It is a fact. The theory is that mutations and natural selection (and genetic drift etc) is solely responsible for the diversity of life on Earth. THAT theory isn't really testable (we can never be sure that some other factor isn't at work), but that doesn't affect the validity of natural selection as a process. Natural selection is no more an "unproven theory" than mutation is. --Robert Stevens 17:26, 23 February 2007 (UTC)

well, 'confusing' is a mistaken term because the 'two' are actually inextricably linked...if natural selection is true or not is not of such great moment per se but the use to which this is put [evolution], the consequences if you will, are massive. You cannot separate the two and indeed the two are not really separated even conceptually...the one rides piggy-back on the other...so again I think more massive, more incontrovertible and more compelling evidence is required for selection, which by the way you have still not provided, is required in order to sustain these dual concepts of selection/evolution. Let's face it there is no other theory in circulation, but that alone is not sufficient reason to accept it as true or even as likely. Maybe you can point to some compelling evidence? I genuinely remain sceptical that selection is empirically observed, which is your claim. thanks Peter morrell 17:42, 23 February 2007 (UTC)

The empirical data demonstrating natural selection is many decades old, and really ought to be known to anyone "teaching biology for 30 years", it's classic science. Further, absolutely no theory in science has better empirical support than does the theory of evolution by natural selection. This "just a theory" debate is silly. Pete.Hurd 17:49, 23 February 2007 (UTC)

Natural selection is one of the most powerful evolutionary mechanisms. Natural selection is a process. Evolution is an observation. Evolution by natural selection is a theory - i.e., a hypothesis which is supported by a large amount of experimental evidence. Sure, there are other important evolutionary mechanisms, but NS is probably the most important and the most powerful.

"I think more massive, more incontrovertible and more compelling evidence is required for selection" - this exists. How much "more" do you want? Guettarda 17:54, 23 February 2007 (UTC)

I suppose the better question is, what do you find unconvincing about the existing evidence? Guettarda 17:55, 23 February 2007 (UTC)

<reduce indent> Three questions:

What "proven" theories are there in science?

Why not read the article instead of asking such questions here?

How are we to interpret your comments as anything other than trolling, arguing against the subject rather than making constructive proposals for improvement to the article?

Think about it. ... dave souza, talk 18:10, 23 February 2007 (UTC)

We are arguing the toss because my amendments to this article were reverted for reasons I do not accept. That is the background. If, as contended above, "Natural selection is a process....(and) Evolution is an observation." then why is "Evolution by natural selection...(only) a theory - i.e., a hypothesis?" no evidence has been offered here except sadly more blather. Ad hominem blather at that. If you are so certain of NS then present some evidence to show it is observation and NOT a theory. What is the difficulty? Yes I have taught biology for 32 years but I have never actually accepted the NS theory. It is accepted by many people as an act of faith or so it seems. I am sceptical of it. I'm sorry if that offends the rank believers here, but it is a worthwhile discussion as opposed to unending rounds of edit wars and reverts. Rank believers should be able to defend their faith. thank you Peter morrell 18:39, 23 February 2007 (UTC)

I don't understand what you mean by "why is evolution by natural selection only a theory". What more could it be? If you taught biology you must be familiar with the scientific method - there's nothing better than a "theory" in science. As for "present some evidence"...I'd say "read the article" and the evidence of evolution article, but I assume that you are familiar with the wealth of evidence that is out there, but are still unconvinced. Hence my question: what do you find unconvincing about the existing evidence? If you don't bother to explain why you are unconvinced by the evidence, there's no point to this conversation. Guettarda 18:59, 23 February 2007 (UTC)

OK that is a better orientation; I find the evidence for evolution completely compelling in every respect in terms of taxonomy, phyllogeny, homology, etc, fossil record...no problem with any of that. My problem is that natural selection alone or even as a major driving force [as stated above in some impassioned outburst by a rank believer] seems too feeble to account for it. Does that make sense? as a force to 'clean up the mess' after catastrophes, maybe it has some point, but beyond that I fail to see how it can lead to much at all except random and directionless genetic drift, and never to speciation. How does that sound? Species don't stay put and diversify, they move to a more suitable habitat. You can see this now with insects in the UK drifting northwards (presumably) due to climate change, as they also must have done after the great ice ages. That's what they do. Therefore, I just find NS too fanciful and feeble to account for the massive leaps in evolution that are apparent in the living world and in the fossil record. I find it hard to accept the very weighty power accorded to NS. Peter morrell 19:09, 23 February 2007 (UTC)

It's helpful, but I still don't understand what you really mean. Are you familiar with Avida and Lenski et al.'s "The Evolutionary Origin of Complex Features"? What about the Rhagoletis pomonella "incipient speciation" thing? Speciation is fairly easy where "hybrids" between the two varieties are less fit than either variety (which is what has been shown in the Rhagoletis thing). I fail to see how it can lead to much at all except random and directionless genetic drift - selection and drift are opposites, how would one lead to the other? Speciation, diversification, and "leaps" (which are not necessarily driven by NS, see evo-devo, for example) are all supported by a lot of evidence. With regards to species migrating with regards to climate change...I think you have oversimplified the issue terribly. In addition, the existence of ring species - not just Arctic gulls, but Californian salamanders - is strong evidence, especially in the case of the salamanders, where the migration is over a much smaller area, and can be matched well with migration following climate change. The fact that two populations at the opposite ends of a continuum can diverge enough that they can no longer interbreed is great evidence of speciation - if you lost the middle and kept the ends, you would have two very distinct species. But the Rhagoletis case is far more compelling. Despite the fact that they can interbreed, and have only been diverging for a few hundred years, there is strong selection against interbreeding. Apples and hawthorn flower at different times, which means that the flies have to emerge at different times. They also cue in to one scent and turn away from the other. If they do interbreed, you run the risk of emerging at the wrong time (and not being able to find the food that you are attracted to). I take it you are familiar with all of this? Guettarda 19:44, 23 February 2007 (UTC)

Many thanks...unfortunately your Ragoletis example, which you said was compelling, only "constitutes a possible example (sic) of an early step towards the emergence of a new species by the mechanism of sympatric speciation," you seem to be bending over backwards to believe all this. I prefer to remain sceptical because I am not a rank believer. You point to the connections where I see only the holes in the same woven fabric of ideas. sorry to disappoint you. I will check out your other references, however. What I meant above about genetic drift was merely that random changes in populations do not necessarily illustrate NS. It is just when viewed through that particular lens that they seem that way. However, what is good about the Ragoletis case is that it shows how adaptable organisms are to subtle changes in the key components of their life cycles, which is fascinating but is not necessarily such compelling grist to the believer's mill as you suppose. My problem is with the curious way these things are pounced on as evidence when they seem wide open to other interpretations. Bad science, as I'm sure you know, is hunting down data to support a pet theory. That is precisely what NS seems like to me. Peter morrell 20:11, 23 February 2007 (UTC)

Mutations are random. Natural selection is the exact opposite of randomness. Think about it for two minutes. Mutation proposes many (random) directions, but only those which are adaptive will be chosen by natural selection. Once this is done, those small, "lucky" variations will be conserved and maintained in the population - and the process starts again. Apparently you fail to appreciate the fact that those small improvements accumulate over time, possibly leading to arbitrarily complex results over time.

Please read Dawkins' The Blind Watchmaker or Climbing Mount Improbable. If you have any questions left, walk into any library or bookstore and have a look at Mark Ridley's classic textbook, aptly named "Evolution". Also you may want to consult the talk.origins website [4]. Natural selection is not what you seem to think it is. --Thomas Arelatensis 21:00, 23 February 2007 (UTC)

More generally, I think we really nead a disclaimer like the one at the top of the Talk:evolution page: this is not the place to argue about natural selection itself. The talk.origins and Wikireason websites are. This article is there to present natural selection as it is currently understood in the field, as clearly and faithfully as possible. This article represents the generally acepted POV, and that's the way it should be. --Thomas Arelatensis 21:00, 23 February 2007 (UTC)

Great idea Thomas, done. returning to DNFTT mode. Pete.Hurd 23:23, 23 February 2007 (UTC)

Peter Morrel so I gather you accept evolution as fact just not that natural selection is a predominate mechanism? You don't deny that nature(environment and other organisms) influences all stages of an organisms life cycle-gene expression, development, survival, reproduction? I gather your argument is that you cannot distinquish between evolution by natural selection vs evolution by genetic drift or gene flow? Actually one can detect genomic changes that have been positively or negatively selected upon, the problem is we often don't know what it associates with. During character displacement in Darwin's finches the changes in beaks is attributable to changes in bone morphogenetic protein, but I think the actually genomic change is in calmodulin expression. I think the best example of speciation is in ectodysplasin signalling in stickleback fish speciation and the changes in lateral plates from salt water to fresh water. This is an example of classic neoDarwinism and natural selection as a shift in gene allele frequencies in transition from saltwater to freshwater. During induced mutagenesis the environment not only selects but intiates a genomic change. I would agree that we often refer to natural selection as an outcome of reproductive success, but the black box is filled with complex ecological,behavioral, and proteogenomic interactions that produce the outcome. Certain copepods alter their phenotype to produce spiny processes upon predation pressure as a protective measure-phenotypic plasticity. I just don't see how you can deny natural selection given the significant body of literature. The same scientific method is applied as in any other field of basic science or medicine. GetAgrippa 21:18, 23 February 2007 (UTC)

1. How is it "bending over backwards" to use the example of Rhagoletis? It's easy enough to come up with a "how" for reproductive isolation (e.g., drosophilids), but it's harder to see what the selective advantage would be. Rhagoletis shows this elegantly. The fact is that you have this extremely rapid divergence which is fairly well understood. NS is the best explanation for this, and the level of change is well within the known power of selection. How can you see such a simple, elegant explanation as "bending over backwards"?
2. Again, why do you reject Lenski's work?
3. "I prefer to remain sceptical because I am not a rank believer" - I don't know about that...being able to remain sceptical in the face of overwhelming evidence takes a lot of faith.
4. "My problem is with the curious way these things are pounced on as evidence when they seem wide open to other interpretations" - please do tell, what other explanations are there that can explain the observations, both the behavioural, physiological and genetic changes.
5. "Bad science, as I'm sure you know, is hunting down data to support a pet theory. That is precisely what NS seems like to me." - very interesting. Care to provide a shred of evidence to support this assertion? What's more scientific - explaining a wealth of independent lines of evidence that support a theory as support for a theory, or taking a wealth of independent lines of evidence that support a theory, dismissing one or two of them as "unconvincing", and then saying "see, there's no proof"?
6. "What I meant above about genetic drift was merely that random changes in populations do not necessarily illustrate NS" - no one claims that it does. You seem to be saying "drift does not lead to the observed changes, so natural selection cannot explain the changes". Since everyone knows that drift and selection are pretty much opposites, I'm getting the distinct impression that you are unaware of what natural selection is. Since you also seem to be unfamiliar with what the scientific method is, I can only conclude that you really are totally unfamiliar with both natural selection and science. Please familiarise yourself with these things first, and stop wasting people's time. Guettarda 08:06, 24 February 2007 (UTC)

well, thanks, it has been an instructive and pleasant dialogue with mostly courteous people and has raised many useful issues. Why is that a waste of people's time or trolling? I still do not accept that NS is as you have stated and perhaps the reason for this is that I would say death is what is directly observable and all organisms die...how and why they die is a matter of human interpretation and because NS is a specific interpretation of the death of plants and animals, so it is essentially more of a theory than an empirical fact. We view the 'random' death of organisms in a specific manner, but that is filtered through the theoretical constructs science provides about the way the world is put together. Therefore, my views have not changed. Death is an empirical observable fact and NS is merely one interpretation of how and why certain individuals die. Beyond that, any further interpretation of the possible impact specific deaths might then have upon the composition and likely change of a population is also theory-driven; it is not empirical per se. There are other aspects of this discussion which have also been enlightening which might be worth commenting upon at some point. If you still think I am wrong, then please say how. Thanks for patiently and courteously giving me your time and views. Peter morrell 13:53, 24 February 2007 (UTC)

Ever willing to chuck a little time and a few electrons away in a good cause, this is a waste of time (and I hope not trolling) because Wikipedia is about verifiable information from reliable sources: any editor's feelings (or incomprehension) and views are "original research" in policy terms, and can't form part of the article. One point – the statement "NS is merely one interpretation of how and why certain individuals die" completely misses the point: "why" is a matter for religion or philosophy, "how" is only relevant to the extent that it affects production of offspring in a heritable way. . ..dave souza, talk 15:23, 24 February 2007 (UTC)

I have read through this discussion and would like to add that Peter Morrell is a serious editor and any edits that contain verifiable information from reliable sources should remain in the article. As noted above, this article should describe natural selection as clearly as possible, with any material on alternative theories being placed on the articles devoted to these subjects. TimVickers 22:01, 25 February 2007 (UTC)

Sad thing is Morrell did not provide a single source, reliable or otherwise, in support of his edit, and makes it pretty clear above that this is a pet idea of his, in reality at best original research. --Michael Johnson 23:34, 25 February 2007 (UTC)

Aye, it is just a bunch of hand waving. The burden of disproof is upto Morrell as a vast literature does not support his bold statement. No editor has given "their" views on the subject but are voicing reliable resources. Morrell has only voiced a vague opinion. GetAgrippa 18:25, 27 February 2007 (UTC)

It is a process. The mechanism is undeniable. Samsara (talk • contribs) 13:15, 27 February 2007 (UTC)

Nomenclature section

Overly long, disproportionately footnoted... reeks of old edit war. Can anyone who's been active on this article longer than I've been watching recall why this is and whether it needs to stay as long as it is? Opabinia regalis 07:53, 6 March 2007 (UTC)

Ummm, IIRC, Axel held that "Natural Selection" required phenotypic change in subsequent generations. Others (Kim, Samsara, myself) felt that such a definition made "Natural Selection" & "Evolution" synonymous when they were in fact different concepts, and Nat Sel applied only to the first half, the selection, and not the response to selection. Yeah, old edit war. Some of your recent edits to the lead seemed to relate to this. Cheers, Pete.Hurd 17:10, 6 March 2007 (UTC)

Hmm, I don't know about 'synonymous', but I agree with your definition, as you've described it. I wasn't trying to stir up definitional issues in the lead, but it did need to be a better summary of the article. At any rate, I think this section needs a good trim; it impedes the flow from basic to more complex, and... well, anybody who knows how wikipedia articles get written can see what caused it ;) I'm always a month behind on these collaboration things, but I thought I should do something on this article, since I nominated it for SCOTM and all. Opabinia regalis 02:39, 7 March 2007 (UTC)

Trim as you see fit, Cheers. Pete.Hurd 03:06, 7 March 2007 (UTC)

Seconded. Samsara (talk • contribs) 03:43, 7 March 2007 (UTC)

Yes indeed it was an old edit war. But at least KimvdLinde and I agreed on one thing — that there are two widely used definitions with an important difference betwen them. KimvdLinde asserts that natural selection can occur without heritability: in this case there would be no evolutionary response. On the other hand I assert that heritability is a pre-requisite and without heritability it cannot happen. My version does not require evolutionary repsonse (because the effects could be cancelled out by other 'evolutionary forces') but requires the possibility of it. (It is close to being synomymous with 'evolution by natural selection' not evolution per se.) The article seems unwittingly to have moved back towards my preference by including the word 'heritable' in the opening line. — Axel147 13:44, 20 March 2007 (UTC)

Peer review request

In case anybody misses it in the thicket of header banners, I've put this article up for peer review. I've been picking at it for the last couple of weeks, but I really think it could use some fresh eyes, especially from non-biologists. Opabinia regalis 03:45, 18 March 2007 (UTC)

Specific question arising from the quite lengthy peer review: should anything be done with the last sentence of the lead, which mentions that some genetic diversity is better explained by genetic drift and the neutral theory of molecular evolution? On the one hand, it may be distracting to readers unfamiliar with the subject to mention a related theory without explaining it, and could be a wedge for people to try to downgrade selection to more 'just a theory, so creationism might be true!' nonsense. On the other hand, it's an important point from a molecular perspective. Any thoughts from the rest of the watchers of this page? Opabinia regalis 03:39, 22 March 2007 (UTC)

I'm fine if it moves out of the lead into a later section, such as the "Selection and genetic variation" section. I think it'll have to expand a bit. I think mentioning it in the lead and not addressing it further in the main body is kinda poor. Pete.Hurd 04:42, 22 March 2007 (UTC)

I think it's important to somehow point out the distinction between evolution (change in genetic makeup of populations, which can be adaptive or random) and natural selection (one of the factors which cause this change). Confusion between the two is rife. Natural selection is one of the driving forces of evolution - arguably the most interesting one, because it explains adaptation. There are other forces, such as genetic drift. I'm not sure about mentioning the neutral theory, which AFAIK is purely molecular and explicitly does not consider phenotypic changes (does it?).--Thomas Arelatensis 13:11, 22 March 2007 (UTC)

I think it's more true to say 'does not explicitly consider phenotypic change'. It was certainly formed for molecular data, and has been interpreted as being most relevant in non-coding regions and in synonymous substitutions, but it doesn't exclude the possibility of neutral changes that have only entirely irrelevant effects on phenotype. Opabinia regalis 02:49, 30 March 2007 (UTC)

On an unrelated note, does anyone know of a good, non-quantitative textbook that covers the material in the 'fitness' and 'genetical theory' sections? The text I have on hand (Rice) is very mathematical and not accessible to general audiences, so an additional recommendation to supplement the sources in those sections would be helpful. Opabinia regalis 02:49, 30 March 2007 (UTC)

Genotype

I know I have raised this before but there seems to be inconsistency in the use of phenotype/genotype now in the opening paragraph.

'Natural selection acts on the phenotype, or the observable characteristics of an organism, such that individuals with favorable phenotypes are more likely to survive and reproduce than those with less favorable phenotypes. If these phenotypes have a genetic basis, then the genotype associated with the favorable phenotype will increase in frequency in the next generation.'

This implies an organism has one phenotype (not one for each characteristic) which is mapped to a single genotype. But how can the genotype increase in frequency unless I am producing clones of myself? Surely it's clearer to say genes (or alleles) increase in frequency? — Axel147 05:17, 21 July 2007 (UTC)

FITNESS NEEDS REWRITING

The Fitness section has some problems. Firstly no quotes, no sources, no citations. Secondly "Modern evolutionary theory defines fitness in terms of reproduction rather than survival." -This should be changed. Dawkins proposed DNA "gene reproduction" as a better explainer, and others in "modern evolutionary theory" have also moved away from simple "reproduction". Here's one reason why- in ants and bees and termites and other haplodiploid insects, the colonies are mainly composed of "sisters." The female workers and soldiers forgo reproduction so that their queen will produce sisters instead (brothers too, but relatively few). In other words, Evolution works for family members other than direct offspring. In fact in any creature, uncles and aunts, even cousins, can pass genetic material and their associated traits without reproducing.(through survival of nephews and nieces, etc) While it may seem a minor point at first, as stated now in the article, the whole theory breaks down the when any example of any creature forgoes reproduction for any reason(including humans) Thirdly the sickle-cell anemia is potentially offensive as well as factually incorrect. "as in extreme examples include many human genetic disorders like sickle-cell anemia"-- Sickle-cell anemia turns out to have great survival value in areas with high malaria infection. This is why many descendants of Africans who lived in malaria ridden areas have sick-cell anemia. Sickle cell disease is the most common inherited blood disorder in the United States, affecting 70,000 to 80,000 Americans. The disease is estimated to occur in 1 in 500 African Americans and 1 in 1,000 to 1,400 Hispanic Americans. (http://ghr.nlm.nih.gov/condition=sicklecelldisease) So to call it an extreme example is, at best, misleading, and unfortunately, one could read into it a racist bias. This could be easily avoided. I am going to edit out "extreme," for now, but the example itself isn't very good (unless someone wants to greatly expand upon how sickle-cell relates to "genetic fitness") 76.19.28.24 15:17, 23 July 2007 (UTC)

I'm not sure what you're trying to say on these points. Modern evolutionary theory does stick with reproduction as fitness. However, if you're trying to discuss something more than fitness, I'm losing your message in the your commentary. As for sickle-cell anemia, what are you trying to say? Sickle cell anemia is a genetic disorder. It might have some fitness benefit with malaria, but even so, non-sickle cell humans have advantages over sickle-cell carriers, even in malarial areas. I don't think it's a "racial" comment whatsoever. Orangemarlin 18:00, 23 July 2007 (UTC)

I too think this needs re-writing because it misrepresents the original use of "fitness" and the phrase "survival of the fittest". Wallace to Darwin,

'I wish, therefore to suggest to you the possibility of entirely avoiding this source of misconception in your great work (if now not too late)...by adopting Spencer's term viz. 'Survival of the Fittest'. This term is a plain expression of the fact; 'Natural Selection' is a metaphorical expression of it, and to a certain degree indirect and incorrect, since, even personifying Nature, she does not so much select special variations as exterminate the most unfavourable ones. '

It is clear that "survival of the fittest" was intended to apply to variations not to individuals. (Or perhaps it could be viewed as applying to lineages or 'races' consistent with Darwin's title of the Origin describing natural selection as 'the Preservation of Favoured Races in the Struggle for Life'.) It is so obvious that being the fittest individual, if this simply means living a long time, is not sufficient per se to propagate characteristics to the next generation it is hardly worth mentioning the point! Darwin in any case clears the matter up, 'I should premise that I use the term Struggle for Existence in a large and metaphorical sense, including dependence of one being on another, and including (which is more important) not only the life of the individual, but success in leaving progeny.' — Axel147 12:03, 25 July 2007 (UTC)

The last sentence of the "Fitness" section contains very bad writing. It reads:

Since fitness is an averaged quantity, however, it is possible for a favorable mutation may arise in an individual that does not survive to adulthood for unrelated reasons, or unfavorable mutations to have a for unrelated reasons.

Could someone who understands this better than I please rewrite it? It's embarrasing. —Preceding unsigned comment added by 74.225.65.124 (talk) 02:44, 1 September 2007 (UTC)

Adam Smith edit

I have a question about this recent edit adding "The second was Adam Smith who, in The Wealth of Nations, identified a regulating mechanism in free markets, which he referred to as the "invisible hand", which suggests that prices self-adjust according to supplies and demand <ref>[[David Orrell|Orrell, David]] (2007) ''Apollo's Arrow'' Toronto: HarperCollins Publishers Ltd. [http://www.apollosarrow.ca/]</ref>. Thus for Darwin, the disaster that was supposed to occur according to Malthus was kept in check and constantly improved by competition (or law of selection)." I don't have the Orrell book, but does it support the assertion that Adam Smith's The Wealth of Nations inspired Darwin in the way claimed? Is there another reference to support the claim? The Malthus influence is well-known, is an equivalent influence from Smith supported by reliable sources? Pete.Hurd 21:14, 15 August 2007 (UTC)

Oh I do have Orrell's book and the edit is fully supported by it. As a scientist in systems biology, I would suppose that Orrell is a reliable source about this. Also, it only makes sense that Darwin's inspiration not only came from Malthus' doomsday prediction but was combined with a more workable approach. Orrell actually says that Darwin was 'likely' more inspired by Smith than by Malthus, but I left this out. --Childhood's End 21:35, 15 August 2007 (UTC)

If I recall correctly, Darwin's biographers left it out too, as it seems to be purely conjectural. There's copious evidence in Darwin's writings about what actually inspired him, and we shouldn't be inventing additional influences. .. dave souza, talk 21:57, 15 August 2007 (UTC)

I also thought it was conjectural... --Childhood's End 22:18, 15 August 2007 (UTC)

Browne mentions that he'd read Adam Smith earlier along with many other authors while developing his ideas about transmutation, but at the point where it comes together with the inspiration of (re)reading Malthus, his other influence was extrapolating from Charles Lyell and A. P. de Candolle's "warring" of species. See Charles Darwin#Overwork, illness, and marriage. By the way, wasn't Malthus a clergyman rather than an economist? .. dave souza, talk 22:29, 15 August 2007 (UTC) Answers self: as well as a parson, a professor in political economy. Should have remembered that. .. dave souza, talk 22:33, 15 August 2007 (UTC)

Adam Smith is mentioned in about half the books in my office that broach the subject of the history of the idea of Natural Selection, but not in the way that this edit presents it, as a direct influence on Darwin's development of the theory... If it's not in the standard Biographies, then I think it might be WP:Undue weight to include it here like this. Pete.Hurd 22:50, 15 August 2007 (UTC)

See Inception of Darwin's theory#Malthus and Natural Law for more on the context. The statement that "Thus for Darwin, the disaster that was supposed to occur according to Malthus was kept in check and constantly improved by competition (or law of selection)." seems out of line with the sixth edition having allowed other alternatives to his bleak forecast. There's an indirect connection in that Malthus on p 2 says "The only authors from whose writings I had deduced the principle, which formed the main argument of the Essay, were Hume, Wallace, Adam Smith, and Dr. Price". It's interesting that on p 11.3 Malthus writes:

"The cause to which I allude, is the constant tendency in all animated life to increase beyond the nourishment prepared for it.

It is observed by Dr. Franklin, that there is no bound to the prolific nature of plants or animals, but what is made by their crowding and interfering with each other's means of subsistence.... The germs of existence contained in this earth, if they could freely develope themselves, would fill millions of worlds in the course of a few thousand years. Necessity, that imperious, all-pervading law of nature, restrains them within the prescribed bounds. The race of plants and the race of animals shrink under this great restrictive law; and man cannot by any efforts of reason escape from it."[5]

Browne makes a passing reference on p 389 to Darwin, musing after conceiving of the theory, envisaging an "invisible hand" selecting. However, she puts a lot of emphasis on the Whig thinking all around Darwin, particularly from Harriet Martineau. In summary, the addition of info on Smith is very dubious, and while his ideas undoubtedly were taken up by people who influenced Darwin, he had other more direct inspirations for the idea. .. dave souza, talk 10:29, 16 August 2007 (UTC)

Yeah, the metophor of the invisible hand is the only reference to Smith that I find in the things like Cronin's "The ant and the peacock", though she references HE Gruber (1974, Darwin on Man: A study of scientific creativity, together with Darwin's early and unpublished notebooks transcribed and annotated by Paul H. Barrett" Wildwood House, London) and SS Schweber (1980, Darwin and the political economists: divergent character. Journal of the History of Biology 10:229-316.) which might be more promising. This is pretty far from my active interests, but I havn't seen really strong evidence for playing up Smith to the same degree as Malthus in influencing Darwin. Pete.Hurd 16:12, 16 August 2007 (UTC)

Selection and evolutionary pressure

I note that this article doesn't even link to the slightly broader article selection, which is in a fairly poor state. Do we want to have this broader article? I'd probably be in favour of keeping it since heaping everything into this article and having nothing linking the other forms together is probably a bad idea. Selection can provide an overview of the subject, such as classification e.g. natural vs. artificial, stabilizing vs. directional etc, as well as levels of selection and other related topics. Another much smaller article is evolutionary pressure. Should this one be merged into selection? I'm not very familiar with the finer details of evolutionary biology so I'm not sure exactly how much potential this one would have. If it is kept as is, perhaps we should look at whether evolutionary pressure or selective/selection pressure is more commonly used, and consider moving it. Richard001 04:11, 28 August 2007 (UTC)

Darwin's hypothesis section fraudulent misquotation

The Darwin's hypothesis section contains a fraudulent misquotation: I have called this principle, by which each slight variation, if useful, is preserved.

The full quotation is:

I have called this principle, by which each slight variation, if useful, is preserved, by the term natural selection, in order to mark its relation to man's power of selection. and the next paragraph But the expression often used by Mr. Herbert Spencer, of the Survival of the Fittest, is more accurate, and is sometimes equally convenient. We have seen that man by selection can certainly produce great results, and can adapt organic beings to his own uses, through the accumulation of slight but useful variations, given to him by the hand of Nature. But Natural Selection, we shall hereafter see, is a power incessantly ready for action, and is as immeasurably superior to man's feeble efforts, as the works of Nature are to those of Art.

Darwin seems to imply that Natural Selection as some sort of nature selection force is superior to mans "feeble" efforts. His intent with the phrase Artificial selection also alludes to this. What confuses the matter is that nobody knows what was his or Spencer's intent with Survival of the Fittest. It could mean anything you want it to mean. Natural selection must be discussed in terms of Artificial selection and Survival of the Fittest since Darwin said SoF is more "accurate" and how it relates to "feeble man" and "nature's power of selection" as he put it in the passage dealing with Artificial Selection. It is not clear what was Darwin's intent with these three phrases and how they relate. He seems to be invoking nature as some sort of conscious "selection" force, unless there are passages that proves that it is not so.

from http://www.gutenberg.org Darwin used artificial selection only once in the book Origin of Species

Slow though the process of selection may be, if feeble man can do much by artificial selection, I can see no limit to the amount of change, to the beauty and complexity of the coadaptations between all organic beings, one with another and with their physical conditions of life, which may have been effected in the long course of time through nature's power of selection, that is by the survival of the fittest.

I propose that we at least cite the full sentence as written down by Darwin? TongueSpeaker 14:27, 12 September 2007 (UTC)

Clarification needed

This sentence appears in the 'Fitness' section. I don't understand what the very last 'or unfavorable...' clause is supposed to mean. " Since fitness is an averaged quantity, however, it is possible a favorable mutation may arise in an individual that does not survive to adulthood for unrelated reasons, or unfavorable mutations to have a for unrelated reasons."Johnor 01:50, 1 October 2007 (UTC)

Looks like the author didn't get out what they meant to say: [6]. It was an IP so I can't really contact them, but I presume they were saying unfavourable mutations can survive among mostly 'good' genes, as long as there aren't too many, and they aren't too harmful. Richard001 04:19, 1 October 2007 (UTC)

It is trying to say that since fitness is a probabilistic quantity (like life expectancy) a mutation could increase an individual's fitness and still not increase its actual reproductive success. This is just like stopping smoking would increase my probability of living longer but I could still get hit by a bus tomorrow. It is is important to distinguish what fitness actually means (expected reproductive success) from the way it is measured or estimated (by averaging actual reproductive success). Maybe the article does not makes this point clearly enough and needs amending. — Axel147 21:51, 2 October 2007 (UTC)