Talk:Long branch attraction

Additions to the article

I think something important to add to the article would be the methods of identifying species that exhibit long branch attraction. The idea is recent so not many people will know how to tell apart the species that exhibit similar characteristics but have a very ancient ancestor.

Examples of species that exhibit long branch attraction would also be welcomed because examples would help to back up the idea.

It might also be helpful to insert a morphology tree to be able to show the relationship between species that exhibit long branch attraction. — Preceding unsigned comment added by Westrick.36 (talk • contribs) 03:34, 2 October 2014 (UTC)

Bad article

This article is very unclear and needs to be rewritten. There is a little too much jargon but more importantly the explanation is poor. I think I understand it and my version is below. I can't edit the page itself because I don't know anything about this topic and I may be completely wrong. Anybody who does know, please rewrite and feel free to pinch all, some of none of this ...

Long branch attraction (LBA) is a problem in genetics which occurs when genes in two different species are similar. It could be that the gene evolved once in the common ancestor of the two species and they really are closely related. Or, it could be that the gene evolved twice, in two completely separate circumstances, and the two species are not closely related at all.

To put it another way, if two evolutionary branches are long enough, and evolve fast enough, it's only a matter of time before one of them looks a bit like the other. This is because genetics only has four nucleotides to play with.

In technical terms ... [insert original article, suitably edited]

If you are an expert in something you should be able to explain it in four sentences to somebody who is generally educated but totally ignorant of the subject. This is how wikipedia should be written - it is a general interest encyclopedia, not a technical one. If you can't explain the thing clearly in four sentences, then you're not an expert. Macguba (talk) 11:21, 12 February 2009 (UTC)

I agree with the idea of writing a better, less technical WP:LEAD. The above wording seems like a good start, but I'm not sure I know enough to say whether it is really clear. I would change "genetics" to molecular phylogeny, because genetics is about things like the function of genes. In principle LBA could happen with non-molecular data but that's less likely per the Bergsten paper (Cladistics 21 (2005) 163–193). Part of what makes it hard for me to evaluate language, or propose alternate language, is the apparent lack of clarity in terms of defining and detecting LBA (especially in practice). In my more cynical moods, it seems like the term long-branch attraction gets applied to any artefactual result of a cladistic analysis. I'm sure that it isn't that bad, but it is interesting to read the parts of the Bergsten paper which have to do with defining LBA. Kingdon (talk) 15:06, 17 March 2009 (UTC)

I am an expert in this field -- here's my stab at a first rewrite. I haven't changed the article because I think it also needs citation of Felsenstein (1978) and Huelsenbeck and Hillis (1993) as well as additional tweaking.

The main goal of phylogenetics is to estimate a phylogeny that matches the branching evolutionary history of a set of species. In some cases, methods to infer this phylogeny can be biased towards a result that differs from the true history. In some cases, this bias is severe enough that even with an infinite supply of data, the wrong inference is made (the method is then called "postively misleading" or "inconsistent"). Long branch attraction (LBA) is the most famous example of this kind of problem. If two branches are very long (have many characters changing along them), it is possible for some of the character changes to have occurred in the same way on each branch (homoplasy). If there are enough of these changes relative to changes that occurred once and match the true phylogeny (synapomorphy) methods that seek to minimize numbers of changes or overall distances may be misled and will put these two long branches together -- the homoplastic changes lead to an attraction of the branches for each other. This can occur with parsimony and distance methods of tree inference, but not likelihood methods, if they use the correct model (an important caveat).

--Bcomeara (talk) 16:54, 30 July 2010 (UTC)

Incorrect Example Figure

The example figure does not show LBA. If LBA is occuring, the long branches (A & C) will be joined together first (i.e. be inferred as "sister" species) and then a branch will link the A-C node and the B-D node. This figure shows the exact opposite!

The figure needs to be redone so that A joins with C, B joins with D, and the internal branch goes from AC-BD. — Preceding unsigned comment added by 99.147.146.206 (talk) 20:40, 1 November 2015 (UTC)

Very poor article

This article would be better off deleted than keeping as it is. It doesn't explain how LBA actually occurs in a way that anyone understands, its examples are full of meaningless boilerplate and illustrate nothing, and even the graphic is wrong. Come on, LBA is due to lineages diverging a lot? How on Earth does their fast divergence result in being clustered together? Someone please look into this. I'm not doing it because I'm not currently working in the field. — Preceding unsigned comment added by 2001:8A0:F009:9A01:5CD4:F85C:6FE4:3692 (talk) 23:46, 16 March 2017 (UTC)

Example

The "Example" section is disappointing. I was expecting to see a real example. Maproom (talk) 07:25, 9 October 2018 (UTC)

aurelia aurita

La verdad no mide consecuencias, y cada información tiene un valor de consecuencias, dando lugar a la redundancia, y en mi opinion, la redundante es capas de proyectar una imágen infinita. señores no es necesario un título o maestría, para ver que la constante elevada, hará el trabajo. la robótica de enjambre, es tan buena, como, tan mala, solo depende del sujeto, que en este caso, es la intención. pido atención a la brillante imaginación de niños , por y para los cuales, la nueva era tiene seguro su legado. Dar a los niños un un brillante enjambre. gracias 45.31.229.68 (talk) 13:02, 23 July 2023 (UTC)