The evolution of skin pigmentation-associated variation in West Eurasia.

[MOESAN]

As for my personal opinion, I take the point that the WHG might have had skin lightening genes we don't recognize. Great. The question still remains, as Anfanger succinctly put it: why then did the WHG living in those northern climes select so strongly for genes we KNOW lighten pigmentation. It would be unnecessary, wouldn't it? I haven't seen that addressed at all.

To me that's illogical. If you don't see that and want to believe otherwise, fine, believe what you want.

Angela, you are right here, personally I believe since long ago that our HG's ancestors were rather brown skinned (maybe dark enough brown). I have just a big "touch of doubt" when I see the reconstruction of Cheddar man, so dark "chocolate"!!!.

[Angela]

Figure 4 shows that 100% of WHGs had the OCA2/HERC2 gene, which is associated with blue eye color and light skin. However, most studies only link this OCA2/HERC2 gene to blue eyes, concluding that WHGs had blue eyes and dark skin. The OCA2 gene is independently involved in the evolution of light skin pigmentation in East Asia and Europe. Two OCA2 polymorphisms (rs1800414 and rs74653330) have been associated with lighter skin pigmentation in East Asian populations. Aside from three genes associated with light skin in Europe (SLC24A5, SLC45A2 and TYRP1) which began to increase in frequency between 19,000 and 11,000 years ago, OCA2 also showed a potential signal of selection in Europeans and played part in light skin pigmentation in Europe. WHGs had only one depigmentation gene but they were probably as light-skinned as East Asians.


Fig 4. Adaptation to high-latitude environments.

Sorry, that won't fly. It takes a combination of snps to result in lighter skin pigmentation. We have decades of practical experience with it by law enforcement agencies. There are algorithms which are highly accurate into which you feed the snps. Someone with the blue eye gene but not the rest of the essential five will have a predicted pigmentation of dark skin and blue eyes. Now, it may not be a prediction for "black" skin, but no way would it come out as a prediction for light skin.

As has been said repeatedly, the only way the WHG could have had light skin is if they had unknown skin depigmentation genes.

[real expert]

I'm quite surprised to see what look to me like personal attacks at Anfanger for having a different point of view.

I want that kind of behavior to end right now.

We've discussed this over and over again on God knows how many threads. People's take on it differs; we know that. What is the point of rehashing it over and over again? Why is it so important to convince the people who think he probably "was" dark skinned? And, for God's sake, does it matter what shade of brown he was??? If he was the color of the San it's ok, but not if he was the color of Nigerians or Senegalese (which I doubt for what it's worth)?

I honestly don't get it.

Also and most important, keep it civil.

Well, I haven’t seen the aforementioned discussions about WHGs and their pigmentation. Therefore, I wasn’t aware of the several threads about him. Furthermore, I brought up a very recent study where the researchers made clear, that they can't really predict the pigmentation of ancient population with confidence. However, dear Angela the issue isn’t about light or very dark brown/ black tone being okay or not. The question was rather about how realistic is that the Cheddar man had the skin color of people who live in a tropical, low latitude region. The WHGs were no newcomers in Europe. Why was for instance, the Lochbour, a WHG like CM predicted as having intermediate color?




Besides, I didn’t attack anyone here. Nonetheless, I find it odd that I have to justify myself in a forum about archaeogenetics and anthropology (that is full of classification of people and discussions about phenotype), why I’m interested in the CM's physical appearance.

It’s beyond me, why people assume the worst or get suspicious when you doubt that the CM was black, but instead rather believe he was intermediate. Anyway, it’s totally normal that if you're not convinced that the WHGs were dark brown/black, that you bring up arguments that support your position. Normal debating behavior, with pros and cons. Anyway, I can assure you that my well-being doesn’t depend on what hue, complexion the Cheddar man had. So, my world won’t be shattered if it turns out that the Cheddar man was the darkest person on the planet.

It just would mean that I was wrong. Let’s be honest, if pigmentation doesn't matter at all, why do then scientists, geneticists waste their time and funds to create algorithm in order to predict the phenotype of people from the distant past?


Plus,when normal people say that the accurate phenotype matters, it doesn't mean that they attach any value on it or pass judgement. It's rather that they want to see ancient people they find interesting, to come alive, so to speak. Surely, some people with agendas will use pigmentation for their ideologies, but the normal archaeogenetics- enthusiasts, nerds just want to satisfy their curiosity. Nevertheless, it's really sad, that even on Eupedia we can't talk chilled and relaxed about the phenotype, skin color of ancient folks without people questioning your motives.

[ThirdTerm]

Fig. S6. Light allele frequencies in ancient and present-day European populations for select SNPs (A) rs2675345, (B) rs4778123, (C) rs2153271, (D) rs3758833, (E) rs12203592, and (F) rs1325132. Nearest genes are labelled at the top of each bar plot.

In the supplementary section of this paper (Ju and Mathieson 2021), OCA2 and TYRP1 are identified as light skin alleles for WHGs. Their frequencies are 50% and 100%, respectively. There are several other pigmentation genes attributed to WHGs such as CTSC (55%) and IRF4 (40%). The IRF4 gene is strongly associated with pigmentation and sensitivity of skin to sun exposure. Previous papers on human pigmentation (Günther et al. 2018) had not found these pigmentation genes in WHGs.

At SLC24A5, rs2675345 shows evidence of change with both ancestry and time, suggesting that even after the spread of the light allele from Anatolia into Western Europe in the Neolithic (7) selection continued to occur post-admixture. Again, not all of these cases involve an increase in the frequency of the light pigmentation allele over time. The light allele of rs4778123 (OCA2) was at high frequency in hunter-gatherers but lower in later populations (SI Appendix, Fig. S6B). From the manually curated set of SNPs (Fig. 2 D–F), rs12203592 near IRF4 also displays a marked effect of ancestry with higher light allele frequency in hunter-gatherers (SI Appendix, Fig. S6E). While rs12203592 was not present in the UK Biobank summary statistics, another SNP at the IRF4 locus, rs3778607, was present but with a smaller ancestry effect (SI Appendix, Fig. S7).
https://www.pnas.org/content/pnas/su...27118.sapp.pdf

[Angela]

Fig. S6. Light allele frequencies in ancient and present-day European populations for select SNPs (A) rs2675345, (B) rs4778123, (C) rs2153271, (D) rs3758833, (E) rs12203592, and (F) rs1325132. Nearest genes are labelled at the top of each bar plot.

In the supplementary section of this paper (Ju and Mathieson 2021), OCA2 and TYRP1 are identified as light skin alleles for WHGs. Their frequencies are 50% and 100%, respectively.

Please look up all the papers on the algorithms used for pigmentation prediction. You will see there in clear statements that one allele alone won't result in light skin pigmentation, a bit lighter perhaps, but not "light", and also that some of these are very low effect genes. The "big" effect genes are SLC24A5 and SLC45A2. Plus, the choice of samples in that study was all screwed up. If I remember correctly it also included SHG, so it throws the figures off.

This isn't rocket science.

It's a fact which has been known for at least a decade and there are multiple papers on it and on the algorithms. Just use google for goodness sakes.

I also have personal experience with them. They "work". NO ONE with only the "blue eye" gene is going to turn out pale skinned when you catch him.

Now, if some of you want to ignore the science on that aspect of this discussion, I have nothing more to say.

If you believe they "might" have had hitherto unknown de-pigmentation genes, that's a different story. It's a reasonable, not a-scientific position to take. It's just that until we find them it's only a possibility, not a certainty by any means, and a possibility which seems illogical to me. That's it. No big deal as far as I'm concerned.

[real expert]

As for my personal opinion, I take the point that the WHG might have had skin lightening genes we don't recognize. Great. The question still remains, as Anfanger succinctly put it: why then did the WHG living in those northern climes select so strongly for genes we KNOW lighten pigmentation. It would be unnecessary, wouldn't it? I haven't seen that addressed at all.

To me that's illogical. If you don't see that and want to believe otherwise, fine, believe what you want.

Angela, you are right here, personally I believe since long ago that our HG's ancestors were rather brown skinned (maybe dark enough brown). I have just a big "touch of doubt" when I see the reconstruction of Cheddar man, so dark "chocolate"!!!.

In my opinion Razib Khan‘s take on the prediction of pigmentation of ancient population is very balanced and informative. He basically says what I try to bring across here.

There are a lot of moving parts in this preprint. Look closely, and you will notice that the authors are careful to stipulate that they can’t really infer the pigmentation of ancient peoples, only the alleles ascertained in modern populations. This matters, because naive deployments of polygenic risk score models trained on modern populations projected on ancient ones seem highly suspect. I’m thinking here mostly of the “Cheddar Man is black”meme. It is true that using modern SNP batteries Mesolithic Europeans are predicted to be rather dark-skinned, but higher latitude humans tend to be paler, on average, than lower latitude humans (albeit, not as pale as the typical Northern European!). But, we can be sure about the alleles we do know about, and, their likely effect (the functional understanding of these pathways is pretty good).


The best modern genetic analyses of pigmentation suggest that variation is dominated by some large-effect loci, but that there is a large residual of smaller-effect loci segregating within the population(I’ve seen 50% accounted for with SNPs, and 50% as “ancestry”,which really masks small-effect QTLs). This is in contrast with the architecture in height, where there are few large-effect loci, and almost all of the variance is small-effect loci. What Ju et al.confirm is that selection “for pigmentation” is due to the large-effect loci; there’s no polygenic selection detectable on the smaller-effect loci for the ancient populations. Importantly, the change in allele frequency isn’t just due to admixture. It’s also due to selection after admixture.

I use quotes above because honestly, I think these sorts of results make it unclear what the selection was for. The general prior is conditioned on the fact that even after a few decades we still think of EDAR asa hair-thickness gene, but it’s one of the strongest signals of selection in the human genome. The “light” allele in SLC24A5 is at an incredibly high frequency in Europe today, and has increased in the last 4,000 years. Though this SNP is impactful for the complexion, it’s hard to imagine how strong selection must be to drive it from 95% to 99.5% (as per 2005 paper on this SNP, the“light” allele exhibits some phenotypic dominance).

As noted in the preprint, there’s not enough data on other regions of the world. It’s hard to assess what’s going on Europe without assessing other regions. The authors do present an intriguing suggestion: that lighter pigmentation in East Asia is driven by smaller-effect genes shifted through polygenic selection.


I’ll present a strange hypothesis: selection for lighter skin at high latitudes through polygenic selection on standing variation naturally takes populations to the coloring of Northeast Asians. But very light complexion, as you see in Northern Europe, could be due to strong selection on the large-effect pigmentation genes, and pigmentation itself may simply be a side effect due to a genetic correlation with the true target of selection.

https://www.gnxp.com/WordPress/2020/...-pigmentation/

[Ailchu]

In a recent Interview in a swiss magazine Krause drops some interesting facts. not everything is relevant for this discussion but i'll just sum up the whole interview a bit:

-4.1-4.2 million differences in genome between 2 central europeans, only 4.3-4.4 million differences in genome between central european and person from Peking.

-If we would meet an ancient Hunter Gatherer in european forests we would probably not be able to see a difference between him and modern Sub-Saharan Africans. their skin was very dark. except that they had blue or green eyes.

-blue eyes probably product of sexual selection.

-developements in agriculture come from a group of migrants from Anatolia.

-the skin colour of this group was similar to modern populations around the mediterranean. lighter than hunter gatherers in europe because of different diet.

-farmers had to develop lighter skin for more northern regions.

-modern scandinavians have lightest skin because scandinavia is the most northern region in the world where people are farmers. that's possible because of the gulf stream.

-farmer women had more children than hunter gatherers because they were able to survive famines better and feed their babies with grain so that women were able to get pregnant again faster.

-not much mixing between them and farmers. mostly farmer male/hunter gatherer female pairs.

-new migrants from southern russia, called the yamnaya, who developed wheels and carts come in.

-six times more men than women.

-modern central europeans, including swiss have 70-80% of genes from these migrants?!(i think this is an error because he probably ment so say paternal DNA? or he does not really talk about the "pure" yamna anymore.)

-in the past this culture was called streitaxt culture(CWC), the nazis called them "aryans". people always thought they came from north but they actually came from southern russia.

-parallel comunities of farmers and steppe for thousand years.

-not that much stealing of women by steppe men but rather farmers marrying off their daughters to steppe people to secure good relations like it was done during middle ages.

-farmers were pushed into the mountains.

-migrations were rarely completely peacefull but without migrations europe would not have gotten very far.

-many who try to stop migration nowadays try to secure a success model that never worked without migration.

-to create a replacement like the one from 5000 years ago, 100 million people from india or the near east would have to immigrate into switzerland.

-migrants from 5000 years ago probably colonised empty land because of pest that killed the previous inhabitants.

[real expert]

[QUOTE=Ailchu;617983]

In a recent Interview in a swiss magazine Krause drops some interesting facts. not everything is relevant for this discussion but i'll just sum up the whole interview a bit:


-If we would meet an ancient Hunter Gatherer in european forests we would probably not be able to see a difference between him and modern Sub-Saharan Africans. their skin was very dark. except that they had blue or green eyes.

This claim of Krause is misleading.

A Tamil Indian with nearly black skin can be still be told apart from a sub-Saharan African even by people who are not anthropologists.

The fact is, that WHGs had a clearly distinct morphology/physiognomy from sub-Saharan Africans. Hence, despite their presumed dark skin they would be distinguishable from sub-Saharan Africans, with their own distinctive looks. The need of some researchers to associate WHGs with SSAs, in spite of the fact, that WHGs are one of the most genetically distant people from Africans, is getting ridiculous, weird and neurotic now.

Anyway, it's not unusual that in interviews scientists make unscientific, misleading remarks. The irony is, that Krause can stress the "blackness/darkness" of WHGs all he wants, that won't redeem him in the eyes of Afro-centrists who will never forgive him for his Ancient Egyptian DNA study. In the Abusir paper he said that AEs had more in common with Levantine people and EEF than SSAs. Therefore, On ES, an Afrocentric forum, Krause is accused of conspiracy to suppress the blackness of Ancient Egyptians, and he's also accused of being a white supremacist, or worse, a Nazi.

-in the past this culture was called streitaxt culture(CWC), the nazis called them "aryans". people always thought they came from north but they actually came from southern russia.

Indo-Europeans speakers were called Aryans prior to the Nazis. The theory of an "Aryan race" appeared in the mid-19th century, thus the Nazis didn't invent the term or the people referred as Aryans. When, will people move on and stop associating Indo-Europeans/Aryans with Nazis or make everything about Nazi ideologies when dealing or discussing the Aryans/Indo-Europeans. Jeez. Besides, the usage of the term "Indo-Aryan"is still common in scientist's circle.

[MOESAN]

@Real Expert
I agree with a lot of your points in this thread. Just we don't know how was precisely the pigmentation of our old HG's, spite I doubt they were so dark as say someones. But in a post of yours, you mention:

[ ... Originally Posted by MOESAN As for my personal opinion, I take the point that the WHG might have had skin lightening genes we don't recognize. Great. The question still remains, as Anfanger succinctly put it: why then did the WHG living in those northern climes select so strongly for genes we KNOW lighten pigmentation. It would be unnecessary, wouldn't it? I haven't seen that addressed at all.

To me that's illogical. If you don't see that and want to believe otherwise, fine, believe what you want.

Angela, you are right here, personally I believe since long ago that our HG's ancestors were rather brown skinned (maybe dark enough brown). I have just a big "touch of doubt" when I see the reconstruction of Cheddar man, so dark "chocolate"!!!...]

In fact, only the vertical letters are by myself. The inclined ones are by Angela.

[Gnarl]

I think, if we have to assume the presence of hypothetical, extinct and undetected gene variants to get the skin color we want, we have left science behind. Not to mention, why do we bother to predict anything from genetics if we have to assume there could have been unknown and undetected genes affecting everything.

Keep in mind, that WHGs lived under glacial weather, climate for 20000 years, a skin tone that is more suitable in the tropical regions wouldn’t make sense during the so-called little Ice Age.

I think there may be some confusion about temperature and insolation here. But first, Cheddar Man was a WHG. As I remember, they were fairly homogeneous genetically, and it is assumed that they were exchanging genes across the population. They do go back a ways in Europe. I would speculate that their population towards the edge of the ice-sheet during the ice age was thinner than further south. In other words, they were mainly a Mediterranean population, thinning as they went further north.

Now speaking as someone who lives further north than almost everyone else, solar radiation decreases with the angle of the sunlight. In other words, the lower the sun is in the sky, the greater the distance the rays has to travel through atmosphere. And that weakens them. It is pretty much impossible to get sunburned here in summer, even with the palest white skin.

However, it is easily possible in winter (except when the sun is gone totally). The high albedo of the snow will reflect the UV radiation in the sunlight leading to a far higher UV load than you'd get in summer. The radiation does not care if the temperature is low. This has consequences for an ice age population. Because although the climate during the ice age was colder, the solar radiation falling on them was not significantly different from todays today.

So if you are going to be spending a lot of time active on snowfields at Mediterranean latitudes, where even the summer sun is strong enough to burn, pigmentation might be a real good idea. Might not be enough pressure to redevelop pigmentation if you've already dropped it, but if you arrived with it, it might not be a bad idea to keep it up.

As far as the development of lighter skin goes; SHGs did most of their lightening before farming. There has been noticeable lightening in Scandinavia in the last 1 000 years. I don't think diet is as central to it as we assume. Maybe sexual selection?

[Angela]

I think, if we have to assume the presence of hypothetical, extinct and undetected gene variants to get the skin color we want, we have left science behind. Not to mention, why do we bother to predict anything from genetics if we have to assume there could have been unknown and undetected genes affecting everything.



I think there may be some confusion about temperature and insolation here. But first, Cheddar Man was a WHG. As I remember, they were fairly homogeneous genetically, and it is assumed that they were exchanging genes across the population. They do go back a ways in Europe. I would speculate that their population towards the edge of the ice-sheet during the ice age was thinner than further south. In other words, they were mainly a Mediterranean population, thinning as they went further north.

Now speaking as someone who lives further north than almost everyone else, solar radiation decreases with the angle of the sunlight. In other words, the lower the sun is in the sky, the greater the distance the rays has to travel through atmosphere. And that weakens them. It is pretty much impossible to get sunburned here in summer, even with the palest white skin.

However, it is easily possible in winter (except when the sun is gone totally). The high albedo of the snow will reflect the UV radiation in the sunlight leading to a far higher UV load than you'd get in summer. The radiation does not care if the temperature is low. This has consequences for an ice age population. Because although the climate during the ice age was colder, the solar radiation falling on them was not significantly different from todays today.

So if you are going to be spending a lot of time active on snowfields at Mediterranean latitudes, where even the summer sun is strong enough to burn, pigmentation might be a real good idea. Might not be enough pressure to redevelop pigmentation if you've already dropped it, but if you arrived with it, it might not be a bad idea to keep it up.

As far as the development of lighter skin goes; SHGs did most of their lightening before farming. There has been noticeable lightening in Scandinavia in the last 1 000 years. I don't think diet is as central to it as we assume. Maybe sexual selection?

I've been reading a lot about Vitamin D since speaking to my doctor about Covid. It's apparently standard now to recommend 5,000 units a day as a preventative. The doctor explained to me that up to 40% of white Americans are Vitamin D deficient. That's amazing to me given that all milk and dairy products and cereals etc. are fortified with it, and we used to be told you didn't need to be out in the sun all that long to get enough.

It makes sense to me that SHG, bundled in furs all the time in the far north might have gotten paler over time in order to get enough Vitamin D. However, they first had to get the allele in order to select it, and the source seems to be the Caucasus. Perhaps mountain living mimics those conditions.

Or it may be tied to another beneficial process and the skin lightening is just a byproduct.

[Gnarl]

I can't imagine a setting where the ancient SHGs were not heavy consumers of fish though. Theres just not that much else here, and only the coast was icefree for a long time. Seems to me that the earliest cases of lightening skin seems to be about the time the snow and icefields go away. Might be a case of competing pressures. Getting extra vitamin D in addition to you diet is good, skin cancer bad. R

[Silesian]

I've been reading a lot about Vitamin D since speaking to my doctor about Covid. It's apparently standard now to recommend 5,000 units a day as a preventative. The doctor explained to me that up to 40% of white Americans are Vitamin D deficient. That's amazing to me given that all milk and dairy products and cereals etc. are fortified with it, and we used to be told you didn't need to be out in the sun all that long to get enough.

It makes sense to me that SHG, bundled in furs all the time in the far north might have gotten paler over time in order to get enough Vitamin D. However, they first had to get the allele in order to select it, and the source seems to be the Caucasus. Perhaps mountain living mimics those conditions.

Or it may be tied to another beneficial process and the skin lightening is just a byproduct.

Don't count out your microbiome, for converting all your nutrients. There are more of them in your body than your own cells. Dairy-Kefir(fresh fizzy type) and or yogurts might be a good alternative. Electrolytes, sodium, potassium, calcium(works with vit D) to lessen the stress of those nasty bugs going around now.

The human microbiome is the aggregate of all microbiota that reside on or within human tissues and biofluids along with the corresponding anatomical sites in which they reside,^[1] including the skin, mammary glands, placenta, seminal fluid, uterus, ovarian follicles, lung, saliva, oral mucosa, conjunctiva, biliary tract, and gastrointestinal tract. Types of human microbiota include bacteria, archaea, fungi, protists and viruses.

[Gnarl]

lol... I read that melanin protects the skin from the dangerous radiation from the Sun. So, why would the human body produce melanin if it lives in cold regions where it has to dress anyway to protect itself from the cold?!

Melanin does protect from UV radiation. You cannot count on high radiation overlapping with low temperatures. Especially if you live in a place with Mediterranean sun and a snowy climate. Your definition of "need to dress up" temperatures likely does not overlap entirely with that of people living in polar regions.

[Angela]

I can't imagine a setting where the ancient SHGs were not heavy consumers of fish though. Theres just not that much else here, and only the coast was icefree for a long time. Seems to me that the earliest cases of lightening skin seems to be about the time the snow and icefields go away. Might be a case of competing pressures. Getting extra vitamin D in addition to you diet is good, skin cancer bad. R

Exactly right. I had two bouts of terrible sun poisoning as a young woman, one on my face, with my face swelling hugely and covered with blisters. Once it was my arm. The first time was on a New Jersey beach because I fell asleep for about two hours lying on my stomach. The second time was in Mexico because I was holding on to a pole of an open jeep. Both times I had to have shots of steroids and stay indoors for three days. Even my eyes got burned in the summer sun of Florida, and I was told I had to wear wrap around sunglasses all the time.

I was told by numerous dermatologists that I had so little melanin that going sunbathing was absolutely out for me. Even high temperatures are a problem because my pores are apparently so small that I don't sweat enough and so my body gets overheated.

I did listen, either always hunting for shade or slathering myself with high level sunscreen, but the result was that I was diagnosed with Vitamin D deficiency a number of times, requiring prescription strength pills for two months each time.

Yet still, I've had three precancerous lesions burned off. Thankfully, squamous cell, not melanoma, but I have to have full body scans every six months. My father, whose skin pigmentation I inherited, had numerous squamous cell cancers removed, one that was pretty serious. His entire family lived in the high Apennines for at least six hundred years. I don't know if that had anything to do with it. It's winter for six months a year there, but I think it's also pretty cloudy.

Black people have the same problem in the U.S. for the opposite reason. No matter how long they stay outdoors, they can't get enough Vitamin D because they have too much melanin.

Also, it is reported that Africans around the equator carry snps to produce LOTS of melanin, to protect them from the sun.

It's all one of those unfair things in life because I adore the sun and the sea, and hate cloudy and rainy climates.

[real expert]

@Real Expert
I agree with a lot of your points in this thread. Just we don't know how was precisely the pigmentation of our old HG's, spite I doubt they were so dark as say someones. But in a post of yours, you mention:

[ ... Originally Posted by MOESAN As for my personal opinion, I take the point that the WHG might have had skin lightening genes we don't recognize. Great. The question still remains, as Anfanger succinctly put it: why then did the WHG living in those northern climes select so strongly for genes we KNOW lighten pigmentation. It would be unnecessary, wouldn't it? I haven't seen that addressed at all.

To me that's illogical. If you don't see that and want to believe otherwise, fine, believe what you want.

Angela, you are right here, personally I believe since long ago that our HG's ancestors were rather brown skinned (maybe dark enough brown). I have just a big "touch of doubt" when I see the reconstruction of Cheddar man, so dark "chocolate"!!!...]

In fact, only the vertical letters are by myself. The inclined ones are by Angela.

To be honest, I don’t know, haven't figured out why WHGs selected so strongly for genes that lighten the skin when having a very dark skin as scientists assert was working fine for them in their environment. My speculation is that the strong selection was for very light skin. It's said that the development of light/pale skin was due to sexual selection. However, in nature nothing develops for aesthetic reasons only but there must be some benefits attached to it , too. Again, why did the WHGs strongly select for genes who make the skin lighter, in the first place, if being dark brown to black was not a problem and beneficial? The Australian Aborigines or Melanesians, for instance, didn’t select genes for light skin for obvious reasons. Besides, I can‘t speak for everybody, but I personally don’t ignore science, I’m just sceptical that predictions for pigmentation of modern people are as accurate as for archaic ones.