It almost sounds like he’s saying “what’s the harm in dark skin?”. Like cave dwelling animals who lost the use of their eyes, any part of our body that is not used has a net cost. It takes energy (i.e., food) and extra mechanisms in the womb or genes during development. So any creature that doesn’t develop eyes (or extra melanin) will use less resources and thus have a better chance of surviving than its cousins who went to all that trouble for no reason. Unless eyes or melanin provide a benefit which offsets that cost, that is.
IIRC, the point with something like melanin in high-sun environment; this is too critical a survival trait to be left to a single gene. Those who have multiple copies of the gene will survive if one gene fails, because they will still have darker skin. Also, it’s a survival trait that these copies are spread among multiple chromosomes, so one bad chromosome doesn’t make the individual less likely to have the survival trait.
That site always cracks me up because the headline is: Redheaded Neanderthals? and then they show a depiction of a Neanderthal with dark brown hair. I guess the red wig was cut form the budget (yeah, they probably just used a stock photo, but still). 
Absolutely- nothing to do with tanning at all, but still explained by a Just So Story…
I’ve seen that one quote a bit, too. I think that one is supposed to be an adult female.
If Europeans and East Asians have light skin due to mutations in entirely distinct genes, doesn’t that suggest that it would be possible for a child born to only European and East Asian ancestors to have skin as dark as from Africa?
No. Genes for skin color are co-dominant, not dominant/recessive as in classical Mendelian inheritance. Offspring show intermediate characteristics to each parent, not one phenotype or the other. Since both parents will contribute an allele that produces light skin (the European version produces somewhat lighter skin than East Asian) the skin color will be intermediate - which is exactly what is seen in people of Eurasian ancestry.
I believe your cite, I just wonder how that compares to the majority of people with rickets being black. Maybe white skin is only an advantage in babies and young children? or maybe it is something else entirely. I do think there needs to be more work on the subject.
In the first generation, yes. But if two first-generation Eurasians mate, then their offspring could get the Asian-mutation gene from their European ancestors, and the European-mutation gene from their Asian ancestors.
The most plausible explanation I’ve seen for why white people exist is sexual selection.
Men generally prefer younger women. Therefore women with features that allow them to look younger than they are have a reproductive advantage. As a result women have developed a whole slew of features designed to make them appear young.
Humans generally get darker as they age. Therefore women with lighter skin have a reproductive advantage.
Essentially the theory is that all humans would be pale if they could be. Once pale genes enter then population, they are selected for in females and if they have no particular disadvantage. In areas with high levels of sunlight, the disadvantage of losing pigmentation offsets the sexual selection advantage and never becomes fixed.
It’s surprising how widespread the correlation between attractiveness and pale skin is. It’s most clearly evident in east Asian populations, where the desirability of pale skin has a long history that isn’t linked to European influence. A preference for paler skin is also seen in South America, amongst Australian Aborigines and in many (most?) African populations,. In those cases it’s harder to determine with certainty that existed before European influence took hold, but it probably was. Ironically the outlier seems to be Northern Europe, where somewhat darker skin is sometimes seen as exotic and attractive, although even there it generally stops with Mediterranean level olive skin rather than “black” skin.
So basically, white skin exists because it can. There’s no penalty for having light skin at high altitudes, and a sexual advantage to it. So once the genes arose they became fixed. There was also likely to be a runaway selection effect involved. Once people became slightly lighter, the effect of darkening with age became even more pronounced, which made a higher degree of lightness even more desirable and so forth in an endless loop.
IOW light skin exists for the same reason that blond hair and blue eyes exist. they’re juvenile traits that have been selected because they are considered attractive, and they are attrative because they are juvenile traits.
Whatever the case, the unmutated allele doesn’t seem to produce skin as dark as sub-Saharan Africans. There are places in central and northern Asia such as Kazakhstan in which both the European and Asian mutations are present, and where one should expect such hybrids, but you don’t see African levels of pigmentation.
Latest documentary I saw said that white skin and fat come from cross-breading with Neanderthals (based on DNA research).
Search for “Neanderthal.Apocalypse.2015”.
Another thing to note is that blond people almost never have dark skin. So there is a direct connection there ( hair type/colour <-> skin colour )
And the people of India have much darker skin than the people, let’s say, of Afghanistan.
The same with people of Indochina. Their skin is darker than the skin of people of China.
(if they haven’t been exposed to sunlight)
But with American natives I don’t see much difference. If this is true, maybe, there was not enough time for this difference to develop… for natural selection to do its thing…
The “white person” mutation occasionally still occurs in Africans. You get a person with light brown hair and pink skin. They are not albinos-- they have color to their hair, and usually rosy cheeks. They look like central Europeans, and can suntan a little, while still having clearly African features. Their genotype for pigmentation is closer to normal Europeans, than it is African albinos.
So, probably there was a group of Africans among whom this mutation was common. If they moved to a cold climate where the sun was far away for long periods, people with the mutation, who would pass it in, had healthier children.
No it didn’t. See post #20.
There is no evidence for this. As has previously been mentioned, the mutations for white skin found in Europeans seem to have originated in Europe and spread from that origin. They did not come from Africa.
No, but they came from people, who came from Africa. The mutation may not have become concentrated enough to become a distinct population until the people among whom it spread had been in Europe for a while (a geological while), and I should have said that, because that’s what I meant, but the mutation was carried from Africa, it just wasn’t very prevalent.
No one knows what causes the mutation to pop up, but up it happens spontaneously, and then is passed along. It never has seemed to get a foothold among an African population to create a distinct group of white people in Africa. There does seem to be a familial connection of some kind-- if you had a sibling with the mutation, you have a slightly higher than average chance of having a child with it, but it’s so rare, that data on that whole population is recent.
I’m finding very little with Google now. I read a print article about five years ago. I don’t know whether I still have it.
Have you seen the documentary?
(I guess “No”)
Are you a DNA specialist?
(I guess “No”)
If you are a DNA scientist, have you compared the data of the two opposing theories, and have you come to a conclusion on which one is true?
(I guess “No”)
:rolleyes:
The idea of cross-breading with a “subspecies”* is annoying, isn’t it? So, let’s reject it.
(* of course there is no such thing as “superior” or “inferior” species)
And the link of post #20 says something about “because of the ability to synthesize vitamin D.” But others have already suggested that this is not true.
That alone tells us that the data, on which that article is based, is outdated.
India has over a billion people. Some are as dark skinned as anyone in Africa, and some are as light skinned as a typical European. With the thousands of ethnic groups, I don’t see that it makes much sense to talk about Indians as a distinct population.
I don’t know about the specific people you’re referring to, but people with ocular albinism lack pigment in their eyes (which results in vision problems) but do have pigment in the skin and hair – although they may be noticeably lighter than other members of their family.
Do you have a cite for that?