Talk:Keratin

"European skin lacks keratin"

On the Mongoloid page, we say currently

The stratum corneum of Mongoloid skin contains lots of keratin, African and Melanesian skin has low amounts of keratin, and European skin lacks keratin.

This is referenced to Pre-History of the Indo-Malaysian Archipelago., a 1985 book by Peter Bellwood. But on this page we say

Keratin filaments and other intermediate filaments function as part of the cytoskeleton to mechanically stabilize the cell against physical stress. Cells in the epidermis contain a structural matrix of keratin, which makes this outermost layer of the skin almost waterproof, and along with collagen and elastin, gives skin its strength.

Am I correct to believe that this sentence does not apply to white people because white people do not have keratin in their skin? This would seem to imply that unlike all other people, and indeed unlike all other mammals, humans of European ancestry such as myself have skin that is extremely delicate and permeable, comparable to that of a frog, through which water and pathogens pass unimpeded.

Am I reading this right?

Am I missing something very important?

Although this claim is on the Mongoloid page, I bring this up here because it's the claim about white people that I find puzzling, not what it says about Asians. Further down the same page, we say

Mongoloid skin has thick skin cuticle and an abundance of carotene (yellow pigment).

Given the similarity of the two words, is it possible that Bellwood also meant carotene instead of keratin? This would make more sense to me. I assume Bellwood's text is top-notch, but he was writing about cave paintings and flint tools ... he may have simply made a silly mistake that escaped both his own eyes and those of his publishers. Are authoritative texts authoritative even for claims that are out of their field?

On the other hand, yet another quote from the Mongoloid page states

Mongoloids have "yellowish skin", because the stratum corneum of Mongoloid skin contains lots of "disks of keratin". and the full paper is available online here (Loomis 1967). Loomis' description makes it clear that he really is talking about keratin and not carotene. Apparently both are yellowish pigments. He cites Carleton Coon's studies in the 1930s. However, Loomis never states that European skin lacks keratin; only that Asians have more of it than others. Does this mean that Bellwood was close but not quite right? There's a lot of difference between low amounts of keratin and none at all. I think that once we can figure out what's really going on, it should be corrected in the Mongoloid article and also repeated here.

Thanks, —Soap— 18:30, 29 September 2018 (UTC)

Its complicated because there are apparently >40 genes for keratin of all the different types. could be that white people lack one particular kind and that Bellwood just used "keratin" for that one kind. for readers' sake, though,. i think we should fix it.—Soap— 20:38, 3 November 2018 (UTC)

Stratified squamous epithelial tissue

Could this be explained in simpler terms: "Cornification is the process of forming an epidermal barrier in stratified squamous epithelial tissue". Thanks in advance, --70.36.51.60 (talk) 09:45, 5 March 2021 (UTC)