Shades of Pale

If there was an advantage to just being paler -  say because of increased vitamin D production – then any mutation that moderately reduced function of a gene in the melanin pathway would be favored, as long as the change didn’t screw up some other function. For that matter, the same is true if sexual selection favored paleness.

You’d see several mutations being selected – different versions in different regions. G6PD deficiency is like this in regions with plenty of malaria – you see a number of different  regionally common reduced-function variants, all of which seem to protect against malaria.

MC1R mutations may be like this in northern-western Europe.  There are many different function-reducing variants – 9 with frequencies > 1%. Mind you, that doesn’t prove that Vitamin D is the driver, but it is consistent with that possibility.

But SLC24A5 is not like that: there is one sweeping variant, not several regional ones, as you’d expect if the true story is vitamin D.  To me, this suggests that a special advantage is conferred by this specific mutation, not just by a reduction in function.  That, and the fact that it seems to have been favored by selection in places like the Ethiopian plateau, which have plenty of UV.

It could be that paleness itself really is an advantage in low-UV areas like northern Europe, and that the common SLC24A5 mutation has a double advantage, extra vitamin D production and something else, which might explain why it has been one of the mostly strongly selected alleles in recent human history

About these ads
This entry was posted in Genetics, Skin color. Bookmark the permalink.

138 Responses to Shades of Pale

  1. Richard Sharpe says:

    Has anyone looked at the penetration of SLC24A5 among African Americans?

  2. Greying Wanderer says:

    Assuming i understand it right that seems the most plausible explanation – very strong selection for the main factor across most of Eurasia, resisted in the tropics because of the light-skin side-effect, resisted by something of equal strength in East Asia, and in parts of Europe either a double helping of selection for the main factor for some reason or an extra dose of selection for one of the side-effects.

  3. Richard Sharpe says:

    This should be the theme song for SLC24A5:

  4. pauljaminet says:

    Seems like a strong argument. There are surprisingly few papers on this gene’s biological function. It is involved in cholesterol function as well as potassium/sodium/calcium transport, so it touches a lot of pathways. http://www.ncbi.nlm.nih.gov/pubmed/23224873

    • The fourth doorman of the apocalypse says:

      The nsSNP encodes the substitution of alanine for threonine at residue 111 (A111T) near a transmembrane region required for exchanger activity, a region which is highly conserved across different species and between NCKX family members. We have shown that NCKX5 is located at the trans-Golgi network of melanocytes and functions as a potassium-dependent sodium-calcium exchanger. When heterologously expressed, the 111T variant of NCKX5 shows significantly lower exchanger activity than the A111 variant. We have postulated that lower exchanger activity causes the reduced melanogenesis and lighter skin in Thr111-positive individuals.

      (Emphasis added)

      That seems to eliminate one of my guesses with respect to neural function.

  5. Steve Sailer says:

    Probably off topic, but how can the red hair / permanently pale skin complex have equal fitness to the blond hair / tannable skin complex? Is the former somehow related to this gene?

    • dearieme says:

      The answer lies in the freckles, Steve.

    • Greying Wanderer says:

      It might not be equal fitness but red and pale may have been a faster or easier way to do it.

      (I think blond hair and blue eyes may have required the Dutch to walk all the way to America, kill all the mammoths, and then head back with a couple of independent East Asian skin lightening genes before the blonde hair and blue eyes thing could fully get under way.)

      (first bit serious, second bit half joking)

    • Greying Wanderer says:

      Also, a lot of ancient writers talk about pale skin and red hair being common all over northern Europe (and maybe even places like Libya) so i think it’s possible the red hair / pale skin version came first (like Neanderthals?) and then got gradually replaced with the “now with free tanning option” version later – hence the remaining distribution being on the far fringe of Europe.

      Would be interesting to see if there was a shift from red to blond in places like Ireland.

    • Magus Janus says:

      presumably lacking a soul is an evolutionary advantage in certain instances.

  6. little spoon says:

    “For that matter, the same is true if sexual selection favored paleness.”
    I’m not claiming I can rule that out entirely but peter frost’s version of how this worked seems really odd. there was intense competition among women for men? When do we ever see that? Usually if men get culled in a war, they just create a harem of all the ladies they can collect, conquered or victorious. So in his theory there was an intense competition between women for a limited pool of men who chose to bestow resources monogamously rather than polygamously and this lasted thousands of years?

    • The fourth doorman of the apocalypse says:

      You are too short for this ride.

    • Greying Wanderer says:

      “Usually if men get culled in a war, they just create a harem of all the ladies they can collect”

      Yes. If they can feed them all – but in an environment where a man can only provide for one family and even that entails a high excess male mortality then the harem solution can’t happen.

      I think that kind of environment must have *some* effect: monogamous traits, provider traits etc but I dunno. In that extreme of an environment i’d be more inclined to think the men would want the women to be a bit stocky and handy with an axe but maybe that’s just me.

    • Sandgroper says:

      http://en.wikipedia.org/wiki/Ten_Canoes

      Yes, I could never persuade myself to believe PF’s theory.

      Incidentally, that film is really worth watching, if you can get hold of it.

    • RS says:

      OT, but he says the men got mass casualties year after year during long, herd-tracking hunts in a taiga-like environment — cold times — and there was not much for women and subadults to hunt or gather, or anyway not in the hard season. So some women, even if healthy and fairly attractive, might have reproduced little.

      I think he suggests this special environment didn’t really exist in NEA (or Canada?), or couldn’t be inhabited.

      Probably relevant is that the environment in question could have been marginal for humans.

      Generally with human mortality — be it endemic forager warfare, or the Black Death in cereal times — there’s inheritance of superior lands by the survivors. They cry for a month, then flourish with many children for a few years, or after the Black Death maybe 75 years. But in this case it may be nothing much is inherited. The death of men may not leave the herd much more exploitable for survivors, if men are mostly being limited by a lethal environment, and not much by over-exploitation of herds — which, by hypothesis, they are only marginally able to impact/exploit. We’re quite used to thinking of humans kicking tail and taking names, except against disease, each other, and resource limitation: and yet there could have been times and places — presumably extreme in nature — where humans had rather little impact on their prey pops. I’m assuming most of the plant/lichen matter available was rather cellulosic/etc and they couldn’t get very far with it ; they needed the ruminants to eat it. The ruminants are cold-adapted since millions of years, and presumably are more blubbery/thermogenic and otherwise able to ride out a four-day blizzard. Humans would do better with a fire, but good luck making one if there isn’t much fuel in general, you can’t possibly carry much on the trail, and it’s snowing two inches an hour. So, not much tail-kicking and name-taking, even if you are pretty good at actually killing the animals when able to keep up with them. At home base there would have been better shelter, probably some fuel, and surely tonnages of animal skins for a blustery night.

      So what you have is (by hypothesis) a labor shortage. Tons of men get killed, but, ‘for once’, that doesn’t really help other men acquire more nutriment which they can apply towards (much) polygyny. And to repeat, women themselves may not be able to get much nutritious food in that environment.

      Of course humans have pushed into other marginal habitats, but if you don’t have to scramble to follow some herd which is nearly the sole resource, it might be a different game. Not to mention many of those habitats are high-UV and none too friendly to depigmentation, even if hypofunctional SLC24A5 is beneficial there on balance.

      So I understand it anyway ; I am usually more interested in other stuff Frost is doing.

      • RS says:

        > hypofunctional SLC24A5

        Or, I should just say SLC24A5-[Ala111Thr] — since Cochran convincingly proposes it’s not solely a matter of reduced function.

      • Greying Wanderer says:

        I think he’s right it was an exceptional environment for a time and that would likely have an exceptional effect on *something*. I’m neutral on what that something might be.

      • little spoon says:

        “OT, but he says the men got mass casualties year after year during long, herd-tracking hunts in a taiga-like environment — cold times — and there was not much for women and subadults to hunt or gather, or anyway not in the hard season. ”

        Wouldn’t that have been the case all along? Humans were in Europe tens of thousands of years before SLC24A5 became prominent there. Humans lived through the ice age without it. Suddenly things became so harsh consistently for thousands of years that only the most beautiful could reproduce successfully? This is still a bit odd because people are white all through Spain and much of Lebanon, where it’s hard to believe that the climate was ever all that harsh. It’s possible that a tribe from Scandanavia (where there was a harsh climate) or something could have overtaken everyone else in Europe and also much of the near east, but is there evidence of that occurring in the last 7000 years?

        Hey, I read that Aztecs used to keep boys in cages and fatten them up before cannibalizing them. I do find that strange, but people did do it. So, I won’t say it is impossible that men opted to devote resources to the children of only one beautiful woman rather than trade a bite here and there with harem companions, but it just seems like a weird strategy to persist for thousands of years.

      • Sandgroper says:

        If females being more fair skinned and lighter haired and eyed also coincided with being relatively more healthy, and therefore having a greater chance of surviving and reproducing, in a particular harsh and demanding environment that was somehow special and different from all of the other harsh and demanding environments that humans have survived in, that could drive diversity in colouring, without needing to invoke ‘novelty’ or sexual selection. The conditions RS describes could result in selection through survival and reproductive fitness, without needing to invoke sexual selection for novelty at all. I just don’t get why PF is so insistent that it *must* have been sexual selection.

      • Steve Sailer says:

        African wasn’t typically up against Malthusian limits, due to diseases and co-evolving large beasts. Instead, many places in Africa needed more human population so the humans could get a critical mass to scare away elephants and other crops-consumers.

    • IC says:

      In north harsh land, you could not even afford a single woman with limited resource. This explained places like Tibet where multiple men married to a single woman. Before industrialization, northern europe is hard place to survive.

      To compete for able provider, north women are most jealous type who can not tolerate other women to share.

      In warm and easy place, women do not need men to raise the offsprings. They can share one alpha male without problem.

      In animal world, the same things happen. Monogamous birds have male as provider.

      • Matt says:

        IC, we’re humans and our pair bonding involves not just jealousy, but warmth, humility and kindness (even for Tiger Moms!), to hold the relationship together.

        You’d expect the monogamous type of woman whose goal is to keep her partner’s affection (to facilitate providing for their kids) to be both warmer, humbler and kinder as well as more jealous. Being more simpatico might be a better way to keep a man (so long as it doesn’t stray into being a total dupe).

        The increased warmth, humility and tolerance for partners might be more increased in the cool places, more than the jealousy. Seems pretty plausible looking at human culture.

      • IC says:

        @Matt

        I believe all human emotions are products of natural selection. Like all physical features, emotion and behavior pattern should have genetic basis which is shapped by long term natural selection.

      • Richard Sharpe says:

        I believe all human emotions are products of natural selection. Like all physical features, emotion and behavior pattern should have genetic basis which is shaped by long term natural selection.

        They must be shaped by selection by necessity.

      • Richard Sharpe says:

        Which, BTW, doesn’t make them any less wonderful or endearing, at least to those of us shaped by similar selection.

      • little spoon says:

        “In north harsh land, you could not even afford a single woman with limited resource. This explained places like Tibet where multiple men married to a single woman. Before industrialization, northern europe is hard place to survive.”

        Vikings were polygamous as were mongols who lived in a freezing desert. Europe is hardly a harsh climate when one considers the whole spectrum of where humans have succeeded. Southern Europe is perfectly temperate and only a minority of Scandanavia and Britain are what I would call harsh (apart from Russia). Where is the proof that resources were ever so limited that polygamy was a non option? Recently people in Somalia have been dying by the million of famine and still, men go in for polygamy. They want a harem. They father seven kids a woman. If 90% of the kids starve, so be it. They want the harem anyway.

        “In warm and easy place, women do not need men to raise the offsprings. They can share one alpha male without problem.”

        Vikings were polygamous until the day the Church forced them to stop being so. Christianity had succeeded in imposing its values of monogamous lifelong commitment all through Egypt and The Byzantine empire before Islam won a military conquest over Near Eastern Christian lands. Harems don’t exist in Europe because Christians defeated Muslims there. The Romans and virtually everyone else in Europe were polygamous before Christianity, a religion that was developed from a warm weather region.

        This mutation apparently came from the Near East, where it was temperate. It did not originate in Europe. Do we know that it first proliferated in Europe? It might have first proliferated deeply in a warm middle eastern region and then continued to be selected for in Europe. Right now middle eastern people tend to be darker than europeans in part because of the recent african slave trade and travel to and from Islamic north africa.

        I think it would probably help to know more about when and where this mutation became predominant in order to assess its historical advantage. Of course, it would be more useful to know what benefit it confers now to see the full range of traits associated with it.

      • little spoon says:

        “This mutation apparently came from the Near East, where it was temperate. It did not originate in Europe.”

        Well, I don’t know that, actually. I thought that’s what was theorized here at least.

  7. Jim says:

    However in an environment of limited resources having a small number of children and hunting to supply them with food might have worked better than impregnating a lot of women where the offspring mostly died. For a male Eskimo to have a harem would only work if he could feed all the children. The women and children left to fend for themselves in that kind of environment would mostly starve. In a northern environment few hunters could support much more than one wife and set of children. Women and children without the support of a male provider were doomed. That could have created more competition among the women to attract a man to form a close bond with.

  8. Greying Wanderer says:

    If almost everyone with the red hair mutation (MC1R) nowadays has some or all of the other large effect skin lightening alleles is it known how light someone with that mutation is if they don’t have any of the others i.e. if they don’t have any of the others are they like ginger albinos?

    • Greying Wanderer says:

      Or would they be a mass of freckles – and as you added more of the other skin lightening genes the freckles would gradually be painted over

      so from this

      to this

  9. jb says:

    My understanding is that while the European variant of SLC24A5 is fairly common in India it has not penetrated at all into East Asia, which has its own separate skin lightening allele. Any thoughts on that?

    • Greying Wanderer says:

      implies they have an equally powerful effect

      (also (?) implies it is the *same* effect as otherwise people could have both)

      • Sideways says:

        If it hasn’t penetrated St all, more likely just a lack of time. If it’s functionally the same as what’s already in E Asians it would be present but rare. If inferior, the spread would go the other way.

        You’ve seen that it’s started spreading into sub-saharan Africa without complete penetration, too.

  10. Pingback: linkfest – 01/28/14 | hbd* chick

  11. Jim says:

    RS – In the Canadian Tundra caribou might be abundant in the summer but in the winter they migrated south and survival through the winter was very difficult. A hunter had his work cut out for him just trying to provide for one wife and a few children. Women and their children without a husband faced almost certain death.

  12. Anon says:

    I’m going to guess it provided something like increased protection against smallpox. According to wikipedia “Smallpox localized in small blood vessels of the skin and in the mouth and throat. In the skin it resulted in a characteristic maculopapular rash and, later, raised fluid-filled blisters. ” So somehow this mutation kept smallpox away from the skin, or made the rash less severe. Smallpox then wiped out the native americans who didn’t have it.

  13. Anon says:

    Wikipedia also says “Smallpox is believed to have emerged in human populations about 10,000 BC. The earliest physical evidence of it is probably the pustular rash on the mummified body of Pharaoh Ramses V of Egypt.[9] The disease killed an estimated 400,000 Europeans annually during the closing years of the 18th century. The virus can be transmitted throughout the course of the illness, but is most frequent during the first week of the rash, when most of the skin lesions are intact.” The date is right and the severity is right.

    • Anon says:

      Actually, nevermind. Smallpox didn’t get seriously into Europe until the crusades, and they were already white by then.

  14. Richard Sharpe says:

    What about lactase persistence? Is that a result of different alleles among different groups, eg African pastoralists who consume milk vs Europeans?

    • Richard Sharpe says:

      OK, seems to involve at least three alleles/genes:

      http://www.plosone.org/article/info:doi/10.1371/journal.pone.0006369

    • Richard Sharpe says:

      The mechanism of lactase non-persistence suggests that there must have been a selective advantage for it to be switched off.

      • RS says:

        Well, not making the enzyme saves energy. Once it is secreted into the gastrointestinal lumen, I greatly doubt it is recovered as such, though the constituent matter may be recovered. You just have to synthesize more.

        So, totally wild guess, it might cost 200 kcal per annum to make it, ie the energy of a couple bananas. Give or take 10 fold. Nothing much, but waste not want not.

      • The fourth doorman of the apocalypse says:

        I figure that turning it off reduces sibling rivalry.

        Of course! Why didn’t I think of that. However, it is not in the offspring’s interest to turn it off it would seem, only in the parent’s interest.

        What an interesting thought and conundrum.

        Hmmm, you are equally related to your parents and your siblings, aren’t you?

        Hmmm again, for species that are weaned before the next offspring arrives this would seem to not be an issue. Eg, Ornithorhynchus anatinus, however, I do not know if they have lactase non persistence.

        • gcochran9 says:

          Babies need milk, they can’t digest regular food, or at least not very well. No teeth, either. So the value of milk to a baby is greater than to an older child who can eat other things. At some point, a kid’s extended fitness is benefited more by letting his baby sib have the milk than by drinking it himself. So he should stop drinking it. On the other hand, the optimal time for the big brother to stop drinking milk, from big brother’s genetic point of view, is not the same as the optimal time from the baby’s point of view. Then the mother has her own genetic point of view…

          Spontaneous cessation of lactase production puts an end to all this bickering – which itself has a cost. I wonder if that’s the explanation. Bickering over genetic interests can be pretty expensive: consider male cats killing kittens, or cainism in Verreaux’s eagle.

      • The fourth doorman of the apocalypse says:

        Isn’t it more likely that those offspring that failed to wean, ie for which lactase production persisted, failed to reproduce since when their mothers died, they died as well.

        So, selection would select for those individuals that switched from being dependent on their mothers to being able to forage for them selves. Switching off lactase production would facilitate that.

      • pauljaminet says:

        That can also explain another puzzle — why milk sugars are made of lactose. Lactose is half galactose which is toxic in excess, and undigested lactose causes GI distress, so it seems like self-handicapping to use this sugar. Marsupials, who wouldn’t have sibling rivalry, don’t have lactose though they do have lactose-bearing oligosaccharides. Monotreme (egg-laying) mammals have minimal lactose. So plausibly the high lactose content of milk from udder-nursing mammals is aimed at discouraging milk consumption by older siblings.

  15. RS says:

    > Actually, nevermind. Smallpox didn’t get seriously into Europe until the crusades, and they were already white by then.

    Hard to say when they turned White. Molecular dating is at least somewhat fraught. Also, there are other alleles and they could have whitened somewhat prior to this allele.

    I had noticed the currently accepted timeframe (or ‘estimate’ to use wikipedia’s term), 11-19 kya, is pretty close to the origin of agriculture in W-Eurasia.

    What are the odds of that timeframe having no relationship to agriculture, I wondered. Especially since we don’t know of anything special going on right before agriculture, that I know of, other than deglaciation. The only thing I can think of is that there is some very nice relief art in Anatolia attributed to some of the last foragers to live there. If true that’s pretty unusual for foragers.

    Agriculture is generally thought to be the birth of the epidemic infections. But infection did not cross my mind. I think pox could be a very nice nominee. It has the right severity, as you say. The idea that pox was in Egypt for millennia without affecting Europe seems absurd, given the ur-ancient traffic on the Mediterranean. (It’s impressive that the Norse didn’t transfer much if any disease to Canada, but that apparently wasn’t much of a sojourn. Also impressive that the Indus River? boat ur-anciently stranded in Australia didn’t transfer much disease.)

    (Historical disease studies are largely a vague affair. No one knows for sure what the Plague of Athens was, and not for lack of effort.)

    If you have a problem, it is that the derived allele originated in Europe — did it? — and farming is obviously a little later in Europe than it is in say Egypt. I’m not sure how well pox would flourish among hunters. We can look at the sequence diversity of the allele’s haplotype to learn where it /probably/ first occurred — /very/ probably, in the case of so fit an allele — though there is no absolute method.

    • RS says:

      > Agriculture is generally thought to be the birth of [MOST OF] the epidemic infections

      I think there’s some evidence tuberculosis(?) may be much older. Maybe a few others.

      • Anon says:

        My thought was that many infectious diseases produce rashes and pustules and boils, and Europeans developed increased resistance to the transmission via the skin. The whitening may have been a side effect. The dates of agriculture -> animal husbandry -> infectious diseases -> whitening seemed right. Maybe not smallpox but something else.

    • gcochran9 says:

      Smallpox is not old enough to have played much of a role in this, particularly in Europe.

  16. Greying Wanderer says:

    If there is someone in Ireland/Scotland who has

    ASIP + TYR/TYRP1 + IRF4

    but doesn’t have any of

    SLC24A5
    SLC24A2
    OCA2
    KITLG

    then we could see if they were dark-skinned or freckled.

    • Sandgroper says:

      Ireland is full of people with dark hair, blue or light coloured eyes, very fair skin, and no or few freckles. I note again (like a worn out record) that freckling is not that uncommon among northern Han. I have no idea why, but it’s not due to recent European admixture – I have evidence for that.

      • Greying Wanderer says:

        “and no or few freckles”

        That’s what I’m wondering. If the later skin lightening alleles effectively paint over the freckles.

        “freckling is not that uncommon among northern Han.”

        cool – that’s one of the things that ought to follow from this idea

        “I have no idea why”

        Easy way to regulate UV?

        If you take someone like her

        and imagine if all the freckles joined up what color would she be – North India?

        Is having having half white, half brown skin a better UV trade-off than a blend between the two?

        dunno but it seems possible

      • IC says:

        “I note again (like a worn out record) that freckling is not that uncommon among northern Han.”

        Very good observation. I am a northern Han and have quite bit freckles on my arm and face. In winter time, my body skin tone is the same or even paler than some German Americans here. Only English or Irish have paler skin than mine. My face is not pink like many Germans. But quite bit of people from my village and my father have exact pink faces like those of northern Europeans.

        Does freckling go with pale?

      • Sandgroper says:

        @IC – observationally, definitely not always. I have seen some really very pale skinned Chinese girls, more pale skinned than most Europeans, who do not have any freckles on their faces at all. But it’s a bit tricky – some freckling can disappear with age, like older teenage or young adult, or even older, some do not. My very imperfect understanding is that the alleles for freckling are different from those that cause pale skin. The two do seem to go together, but the explanation on Wikipedia is that freckles, when they occur, are simply more visible on more fair-skinned people.

        Red hair and freckles seem to go together a lot in Europeans, but not exhaustively always, obviously. There are some red heads who do not freckle. Some blonde people freckle, some don’t. Some people with black hair freckle, but not with such high frequency as people with red hair.

        Wikipedia says that freckling can occur in people of any ‘ethnicity’, so the observation (and in your case, the fact) that freckling can occur in Han, or at least in northern Han, is obviously correct. I know, my mother-in-law was northern Han, definitely no European ancestry, confirmed by genotyping, and she had freckles. And they obviously occur in Europeans – among Europeans living in very high UV radiation environments, such as in Australia, they occur really a lot – nearly all younger people have them to some extent.
        Among other groups, I can’t say. I have a lot of exposure to Chinese people, really a lot, so I see big samples of people. I do not have anything like as much exposure to people from other groups, so I see only very much smaller samples. And on some skin the freckles might be effectively invisible except on very close examination. I don’t want to go around the public train with a magnifying glass, peering at people’s skin.

        But China’s most famous international super-model, Lu Yan, has freckles. She is from Jiangxi, which is obviously south, but I do not know where her parents came from. From her height, very fair skin and face shape, I expect they might have moved to Jianxi from somewhere in the north, but I am guessing, I don’t know that for sure.

        There was a Greek researcher who did light reflectence studies on a sample of Chinese, a sample of Europeans and a sample of Africans. The light reflectance spectra were nearly identical for Europeans and Chinese, except that the Chinese spectrum had slightly less pink in it – so it is not correct that Chinese are ‘yellow’ – the truth is that Europeans are more pink than Chinese. And if the grouping term ‘white’ is used, it should encompass both Europeans and Chinese.

      • Matt says:

        If you take someone like her http://i.imgur.com/Ew5G7OL.jpg and imagine if all the freckles joined up what color would she be – North India?

        There’s a lot of darkening and contrast in the filters there. Photo filters are cool things, but bear in mind if you put the average Chinese in that picture with her, applied the same filters, then they probably would look like one of darker skinned among the Malays (in skin tone terms).

        And if the grouping term ‘white’ is used, it should encompass both Europeans and Chinese.

        Skin color maps give about the same median color in Turkey as North and Central China, and about the same in South China as the Bedoin Arab and Egyptian influenced parts of the Levant. Skin reflectance seems pretty consistent with this.

        So if Turks and Levantine Arabs fit the descriptor, no real reason why Chinese shouldn’t.

  17. MT Isa MIner says:

    I have zero knowledge in this area so shoot at will. What about Phenylketonuria? It is pleiotropic ( including intellectual retardation), has a metabolic pathway, a widely varying incidence.

    Recent studies have shown that the R408W mutation clusters in two regions,
    north western Europe with the highest frequency reported in Ireland, and eastern Europe
    with the highest frequency reported in Lithuania.’ A detailed study of the association
    between R408W and RFLP haplotypes has shown that R408W is strongly associated with
    haplotype 1 in north western Europe, whereas it is strongly associated with haplotype 2 in
    eastern Europe. This led to the suggestion that R408W has two independent origins in Europe,
    one “Celtic” and one “Slavic”. “2 Extensive examination of the association between R408W
    and polymorphic VNTR and STR sites at the PAH locus supports this hypothesis.” http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1051781/pdf/jmedgene00279-0058.pdf

    It may also have been able to be treated with milk products. This casein peptide (CGMP) is released by rennet during the manufacture of cheese or rennet casein. This could tie in with the LP?

    From wiki:
    Some research has indicated an exclusive diet of breast milk for PKU babies may alter the effects of the deficiency, though during breastfeeding the mother must maintain a strict diet to keep her Phe levels low.
    And again:
    Another interesting treatment strategy for PKU patients is casein glycomacropeptide (CGMP), which is a milk peptide naturally free of Phe in its pure form[30] CGMP can substitute the main part of the free amino acids in the PKU diet and provides several beneficial nutritional effects compared to free amino acids. The fact that CGMP is a peptide ensures that that the absorption rate its amino acids is prolonged compared to free amino acids and thereby results in improved protein retention[31] and increased satiety[32] compared to free amino acids.

  18. MT Isa MIner says:

    Yeah, Fourth, whether it was lead or uranium from Mary Kay that stopped me from a stellar career in astrophysics has always been the question. Must be lead as it causes brain damage.

    I don’t know that I’m a fan of the lead = aggro theory for diminished crime in USA. Seems more like aggro is a feature of certain populations not a bug.

  19. RS says:

    > Vikings were polygamous as were mongols who lived in a freezing desert. Europe is hardly a harsh climate when one considers the whole spectrum of where humans have succeeded.

    This was in the glacial period though — boy is it a different world. (An ice age, technically, is anytime there is ice on the earth.) I don’t think there were many trees in much of Europe.

    > Wouldn’t that have been the case all along? Humans were in Europe tens of thousands of years before SLC24A5 became prominent there. Humans lived through the ice age without it. Suddenly things became so harsh consistently for thousands of years that only the most beautiful could reproduce successfully?

    It was glacial the whole time sapiens was out of Africa, until 12.5-15k years ago. Most of Eurasia was uninhabitable, or ‘habitable’ like today’s Middle Alaska.

  20. RS says:

    > At some point, a kid’s extended fitness is benefited more by letting his baby sib have the milk than by drinking it himself. So he should stop drinking it.

    > Spontaneous cessation of lactase production puts an end to all this bickering – which itself has a cost. I wonder if that’s the explanation. Bickering over genetic interests can be pretty expensive

    How well does a three year old human cognize or intuit the intestinal problems he’s getting from milk? I guess his mom could cognize it and point it out to him. But it seems other animals, especially juveniles, are too dumb, so they must just pay the price of weaning conflict (though perhaps some animals are too placid to have it) and then repress lactase to save a little energy.

    • The fourth doorman of the apocalypse says:

      There’s a whole bunch of sloppy language being used.

      The cessation of lactase production is strongly conserved across many mammalian species, it seems. That requires an explanation, and sibling rivalry has been suggested as one. We simply inherited that characteristic along with lots of other mammalian features, like nipples.

    • Sideways says:

      Figuring out that eating something made you sick and to stop doing that has to be some of our oldest hard-wired behavior

  21. dave chamberlin says:

    What is the evolutionary reason for male baldness? I have read various opinions on line and I don’t trust them. Cochran may have more interest than most on this very important question.

  22. Peter Frost says:

    SLC24A5 is one of three genes involved in the whitening of European skin, the other two being SLC45A2 and TYRP1. This whitening occurred over a relatively short time and long after the entry of modern humans into Europe some 40,000 years ago. Sandra Beleza’s team estimates that all three genes “went white” between 11,000 and 19,000 years ago. Victor Canfield’s team, working only with SLC24A5, estimates between 7,600 and 19,200 years ago.

    So, yes, white European skin is not an adaptation to weaker sunlight; otherwise, it would have evolved much earlier. Are we looking at some pleiotropic effect then? In that case, this effect would involve not only SLC24A5 but the other two genes as well. Perhaps, but I’d like to see the evidence.

    No, I’m not going to invoke sexual selection to explain the apparent success of the “European” allele for SLC24A5. Sexual selection, especially sexual selection of women, occurs under very limited circumstances. I believe that there was an episode of very intense sexual selection of women, but this episode was confined to northern and eastern Europe during the time frame of 10,000 to 20,000 years ago, i.e., the last ice age.

    How then do we explain the much greater geographic and historical success of this allele? The answer is part of the larger one of why lighter-skinned folks have done better than darker-skinned folks. Mean temperature is inversely correlated with technological complexity, even going back to the hunter-gatherer stage of cultural evolution. This is partly because of the need for heat conservation (tailored clothing, insulated shelters) and partly because resources are more dispersed and typically available for short periods of time. There was thus strong selection for time budgeting, forward planning, and the ability to manage storage technologies (ice cellars) and untended facilities (traps, snares). Northern hunters were pre-adapted for technological complexity and thus better able to exploit the sort of complex cultural environments that developed much later in time.

    Is this the whole story? You point to Ethiopians as an example where SLC24A5 seems to be present at a higher frequency than Caucasian admixture. This discrepancy can probably be explained by social selection for lighter skin, as indicated by an Israeli study that found light-skin preference among Falasha children. This preference may be learned, although there is evidence that people are predisposed to associate lighter skin with certain good qualities (as a result of a mental algorithm that uses skin tone for identification of women and young infants). For whatever reason, social selection for lighter skin is a reality in Ethiopia, and it probably has had some impact on the prevalence of SLC24A5.

    • Anon says:

      I was on the subway today and from looking around it seemed definite that sexual selection had occurred.

    • IC says:

      Social selection is good idea to explain this whitening process. Agriculture is associated with more food than hunter-gather society. More productive society, more inequality. People at higher end class do not need to work in the field with less tanning of their skin. With skin tone as indicator of social class, the selection pressure is toward pale genes.

      Just hypothesis with no data here.

    • Jason says:

      Regarding “social selection”, there’s a chapter in R.A. Fisher’s Genetical Theory called “Social Selection of Fertility” in which he argues that in settled agricultural societies, social selection is associated with lower fertility.

  23. Diana says:

    I’m curious as to how tall this dark-skinned blue-eyed man was. Did they check for that?

    What was his diet? If his diet was heavy in Vitamin D rich foods, no need to synethsize it from the sun.

    Also wonder about condition of his teeth. From what I’ve read, HG peoples have good teeth, even w/o floss.

    TEN CANOES = ten stars. Thumbs up. (But I do think that HG women were able to feed themselves reasonably well, “collecting women” was purely status and men did it because they could HG societies were not at all egalitarian. Another hippie myth.)

    • Sandgroper says:

      Aboriginal women collect dead perenties.

      Of course, before a woman can collect a dead perentie, she has to kill it. Find it (not easy), stalk up close, chase it until it turns on her, 2 metres of it, all teeth and claws and whipping tail, and club it to death with her digging stick.

      Me, I don’t want to get anywhere near those damn things.

    • Sandgroper says:

      Diana, I can’t find anything on the height of La Brana 1 and don’t have access to the paper, but from memory the Loschbour guy was about 5’6″. Both look like they had dark(er) skin, probably blue eyes and dark hair, 1,000 years apart, one in Spain and the other in Luxembourg. It’s not just one data point established by one team of researchers, it’s two established by two different teams in two different countries. The Loschbour guy’s ability to digest starches was about as high as people in modern agricultural societies, which made him different from the Motala HGs in Sweden, who were lower, but his diet was stated to be ‘mostly land animals – red deer and wild pigs’. I thought that was kind of interesting, but it’s only one data point, and there must have been a natural range of variation.

  24. Greying Wanderer says:

    @IC

    “I am a northern Han and have quite bit freckles on my arm and face…Does freckling go with pale?”

    That’s what i’m wondering. It seems to me it might be a quick and easy “loss of function” way to get more UV but not too much.

  25. Karl Zimmerman says:

    I think the penetration being so limited into East Eurasia is quite telling. I mean, there are plenty of admixed East/West Eurasian populations (Uighurs, Kazakhs, Uzbeks, Hazara, to a lesser extent Altai and Mongols, etc) and yet the proportion of derived SLC24A5 is basically identical to the West Eurasian proportion in the different populations. West Eurasians penetrated even deeper than this in the Bronze Age as well, going deep into modern Gansu in China, and perhaps even forming the ruling class of the Shang Dynasty, yet leave relatively little genetic record in this area.

    This seems to suggest that even if there was an advantage aside from skin color, it was a particular kind of advantage, one which East Eurasians already evolved their own genetic architecture for. It could not have been an additive advantage (like intelligence) because even if East Eurasians developed their own high IQ genes, adding an West Eurasian high IQ gene to the mix should have been more advantageous. Yet it clearly was not.

    • Greying Wanderer says:

      “It could not have been an additive advantage (like intelligence)”

      What if the mechanism was the same e.g. breast-feeding -> iodine?

  26. Greying Wanderer says:

    If SLC24A5 has something to do with breast-feeding/breast milk/iodine -> IQ then there ought to be a correlation between similar / adjacent populations who have notably different SLC24A5 frequencies and their average IQ.

    (Not sure how much it would be but if it has been selected for so strongly then i assume it would be measurable but not massive.)

    .

    Personally I think MA1 may well have been original color I think both La Brana and Louschbour more likely looked like this

    http://www.imdb.com/media/rm3089345536/nm0614165?ref_=nm_ov_ph

    but (before the arrival of the near eastern skin lightening alleles) with freckles like this

    or this

    .

    If so there’s probably a Scottish or Irish descended person somewhere that would prove it.

  27. Pingback: Picky Men | Chateau Heartiste

  28. RS says:

    > Sexual selection, especially sexual selection of women, occurs under very limited circumstances.

    So you are equally attracted to all women?

    I don’t know what you think, but I think harmful alleles of middling effect size are probably very strong causes of some of us being better-looking, smarter, more charming, more agile, healthier etc than others. These phenotypes do not look like they are (to much of an extent) trade-offs against energy economy or anything else. They’re just better, which would explain why the top half of the human agenda is to get warm (or cool), eat something halfway palatable, and get in bed with someone as high as possible in the above traits.

    I think sexual selection is pretty powerful, then, in just about any sexual organism sophisticated enough to perform sexual selection. And for any near-monogamous mating system, there will be no little sexual selection on the female. It’s not hard to observe rather extensive courtship behavior in Euro & Noram birds, which are almost all near-monogamous, though it is not easy to observe that a lot of courtships probably end in non-mating and that many probably end in rejection of the female by the male. The courtship is hard to explain if pairing is indiscriminate — maybe not impossible to explain. But consider this, many of these birds are quite colorful (and I don’t mean green, brown, or gray), often enough even the female ; hard to see how this is a big aid to survival when the main predator of small birds (before cats) was probably hawks, which have strong color vision and whose capital sense is, easily, vision. The answer is its not an aid to survival its an aid to marrying well.

    > I believe that there was an episode of very intense sexual selection of women,

    That much seems to me much more defensible than the above.

    > 10,000 to 20,000 years ago, i.e., the last ice age.

    Are you referring to some intensification within the last glacial age? Said age did not begin 20kya, it began ~120kya. Not that that really matters for your theory.

    • The fourth doorman of the apocalypse says:

      Based on the following:

      it does appear that the last ice glacial was back a bit further than 20kya. By about 12kya it had started to warm up a few degrees and by 8kya it was great. It’s been mostly downhill since then, but we are not yet back to a glacial and there has been a recent uptick, not unlike other upticks during other parts of this interglacial we are in.

  29. RS says:

    > My thought was that many infectious diseases produce rashes and pustules and boils, and Europeans developed increased resistance to the transmission via the skin. The whitening may have been a side effect. The dates of agriculture -> animal husbandry -> infectious diseases -> whitening seemed right. Maybe not smallpox but something else.

    I agree, maybe something else, maybe Cochran can suggest another disease. Though I don’t see how smallpox in Europe is ruled out before such-and-such a date. It may be a rather distinctive disease, but what if it changed a bit in its manifestations.

    Also, note that Frost has just given us a later possible date for the derived allele. (“Victor Canfield’s team, working only with SLC24A5, estimates between 7,600 and 19,200 years ago.”)

    Once you brought up infection, my first thought was actually not about pustules or skin, but about white blood cells. Or just cells in general. If they express the gene, it could credibly alter host-parasite interactions.

    Given the failure of the derived allele in the far East, it would make sense if the disease came from that direction and was already under control out East. Its conceivable the disease is now extinct and unknown. Its conceivable the disease is actually EBV or acne (or whatever) but was formerly 20x more virulent.

    However, we probably should not assume that the derived allele is something Easterns had no need for in abstracto. I hear they are rather anciently diverged from W-Eurasians, so it should be conceivable that the solution (at least in part) is that their average general genetic background simply doesn’t tolerate the derived allele very well, and/or doesn’t fully allow it to exert its virtues.

  30. RS says:

    The birds on this plate are roughly representative of temperate-zone Birds of Color, wrt degree of gender dimorphism for colorfulness.

    If they’re like most others in their Order, these birds are probably ‘monogamous’ but with ~five times more cuckoldry than you’d find in middle-class Western humans. (And as a bonus moral failing, brood parasitism of conspecifics, ie egg dumping.)

  31. Diana says:

    “One thing to keep in mind is that recovering ancient DNA is extremely delicate work and it’s possible for the scientists’ own DNA to accidentally get mixed in with the sample.” from Steve Sailer’s blog, about this finding.

    What would have contaminated the sample? Modern alleles? That would have yielded the opposite conclusion: that the prehistoric hunter gatherers were white. It would be highly unlikely for the sample to be contaminated by alleles from scientists that no longer exist!

    Something tells me this is going to dismay, disgust and disconcert white nationalists.

    LOL a thousand times.

    • Sandgroper says:

      Big time. I’m mildly amused by the people whose knee-jerk reaction is to tie themselves in knots trying to find ways to convince themselves that dark skinned Mesolithic HGs in Europe were really white.

    • The fourth doorman of the apocalypse says:

      Something tells me this is going to dismay, disgust and disconcert white nationalists.

      But then again, they might get with the program and say: “Hey, we wiped them out, pretty much …”

      In the same way the Muslims who want to kill the infidel or ensure women know their place are human, so too are white nationalists, or are they simply the current target of your two-minutes hate?

      • Sandgroper says:

        Wiped out would be a bit of an exaggeration, unless mtDNA subhaplogroups have somehow been totally misconstrued. Reduced to low frequency with one or a few notable exceptions seems more accurate.

        The way I am seeing it today (as opposed to yesterday or tomorrow, because new information really does seem to be coming out that fast now) is that skin lightening among people living in Europe, might have coincided with the migration of farmers from the Near East into Europe – it seems at least suggestive of that. And maybe more again with subsequent migration events. If that is wrong on the basis of what is known and objective deductive logic, fine, I’m happy for someone to point out flaws in my amateurish, imperfect grasp – I’m not going to be offended. It’s not how I earn my living. It’s not a personal insult. It’s very complicated, and I’m a biological idiot. I am very interested in trying to understand the reality of what happened. It doesn’t actually matter to me what that reality was, I just want to know what it was. I don’t have an agenda that I need to make it fit to.

        I will not admire someone whose argument is driven by ideology rather than what is known and deductive logic. Someone who is evidence-and-logic driven pointing out what appears to be a flaw in deductive logic based on wishful thinking or ideology is not a hate event. I guess someone might object to being found to be unintentionally amusing but, honestly, there are worse things than being gently mocked.

      • Diana says:

        I’ve no idea what you are talking about. What would have “wiped them out”? A genetic adaptation? Please try to express yourself in the English language and not a code intended for cult members.

    • Greying Wanderer says:

      @Diana

      Alternatively people trying too hard to prove the opposite might blind themselves to the obvious – assuming light skin, UV and latitude are connected.

      http://www.terradaily.com/reports/Researchers_identify_genomic_variant_associated_with_sun_sensitivity_freckles_999.html

      (And by extension light skin alleles from the near east are more likely to be a side-effect of something equally useful in mid latitudes.)

      • Sandgroper says:

        Just – you made me think of something. The map in GC’s Tar-Zan post is a map of yearly mean of daily UV irradiation. At mid-latitudes, the seasons are much more pronounced than in the tropics – sorry, that’s stating the obvious, but it’s worth keeping in mind. If we looked at a map of year-round variation in specific locations, it would look very different.

        In southern Australia, in summer, the sun will roast you alive. Perth and Brisbane are the skin cancer capitals of the world. Perth is at about latitude 34 S. Brisbane is about 27.5 S. Excessive sun exposure is a major problem for white skinned people (at least ancestrally European white people, because Chinese people appear much less susceptible to skin cancer, and they don’t sun burn much either, although they do have a tanning response) in Melbourne, which is a shade north of 38 S.

        In summer, it can actually be more bearable to be outside for longer periods in the humid tropics than in the mid-latitudes, provided you can tolerate humidity and don’t suffer heat stroke because your evaporative body cooling system doesn’t work very well when the ambient humidity is high. 35 Celsius in the shade is hot, but it’s nowhere near as hot as 45 Celsius (and if anyone says “Yeah, but it’s a dry heat” I’ll scream – 45 is 45, no matter how dry it is).

        But alongside that, what has been found is a surprisingly high incidence of Vitamin D deficiency among white skinned people living in southern Australia. Perversely, it looks like this has increased with the effectiveness of public health campaigns warning people of the risks of skin cancer caused by excessive UV exposure – in other words, it looks like people applying sun screen to protect their skin from excessive UV exposure has resulted in an increase in Vit D deficiency. What the health consequences of that might be, well…I’m no expert, but the consensus seems to be that it’s not a good thing, at least for people of modern European ancestry.

        Being very careful here, at least if you are white skinned, it looks like what you need is enough UV exposure frequently enough, but if you have too much – problem. Maybe that problem is not enough to cause an effect on reproductive fitness, because a lot of skin cancers don’t occur until after reproductive age. Fatal melanomas in young people certainly do occur, a good pal of mine died of it, but they are relatively rare. But who knows. Just being out in the sun in summer there for an extended period is enough to give a lot of people very serious sun burn, which is no fun at all – I know people who had to be hospitalised with it. Never mind reproductive fitness, just staying out there exposed for long is unbearable on a daily basis, unless you are Aboriginal, and even then you are likely to find a patch of shade to sit in during the middle of the day.

        It obviously makes a big difference, also, between whether you live your whole life outdoors, naked, or whether you wear clothing and spend a lot of time under shelter, and that’s not irrelevant to the whole of the Neolithic, and a lot earlier.

        So, looking at broad correlations between latitude and skin reflectance, one needs to be mindful that it’s not going to be just a simple correlation between annual mean UV, latitude and skin ‘lightness’, at least not one that is going to tell you anything very simple and obvious about causation unless you can somehow factor in a lot of confounding. Plus bearing in mind that reversing paleness seems to be a lot more difficult than acquiring it. Plus diet is not irrelevant.

        And that’s without even thinking that skin lightening might just be a pleitropic effect from something else. Which I’m certainly not discounting.

      • Diana says:

        @GW, I’m not trying to prove anything. I really don’t understand what you are talking about. It’s total gibberish to me.

  32. Diana says:

    “It would be highly unlikely for the sample to be contaminated by alleles from scientists that no longer exist!”

    I meant that the alleles no longer exist, not the scientists.

  33. Greying Wanderer says:

    @Sandgroper

    “Being very careful here, at least if you are white skinned, it looks like what you need is enough UV exposure frequently enough, but if you have too much – problem.”

    Yes, that’s what i was wondering – if you need *some* light skin for the UV i.e. a blend of brown and white doesn’t work, but too much causes a different problem, then freckling might be a solution – kind of like UV camo paint.

    • Sandgroper says:

      Yeah, I’m seeing your point. No idea, but it seems like a neat theory to me.

      • Diana says:

        You have to take diet into account. A diet adequate in Vitamin D changes the requirements.

        Alternatively they could have been Vitamin D deficient and just lived miserable, shitty lives and died early. No golden years for cave peeps.

    • Matt says:

      I can imagine a situation where exposing half the uv responding D producing receptors to lots of UV is worse than exposing all the receptors to some (lesser) UV, simply because the exposure may be beyond what the receptors can usefully make use of (imagine sending twice as much steel to half the factories while the other half lie dormant – it’s not necessarily going to be usefully processed, as there’s only so much each factory can do).

      But whether any of that could ever be tested, who knows.

      • Sandgroper says:

        I was going to say that a suspected adaptive response to seasonal variation in UV is tanning, but it maybe only works well enough in a limited set of environmental conditions, still happens in some people who live in different environmental conditions where it doesn’t actually do much, and there’s no obvious way to test either tanning or freckling as originating as an adaptive response.

      • Greying Wanderer says:

        I think it’s likely there’ll still be a few people around in NW Europe with either IRF4 or MC1R and without the SLC genes.

  34. Peter Frost says:

    > Sexual selection, especially sexual selection of women, occurs under very limited circumstances.
    So you are equally attracted to all women?

    RS,

    Sexual selection is not the same thing as sexual preference. In other words, what you prefer is not necessarily what you will get. It all comes down to the law of supply and demand.

    Sexual selection occurs when too many of one sex have to compete for too few of the other. Normally, the males have to compete for the females. The reverse is rare in nature. It happens when (1) males die much earlier than females do and (2) the costs of providing for a second mate are too high for almost all males. In human hunter-gatherers, the ratio of men to women on the mate market declines as one moves away from the equator. It reaches its lowest point in open steppe-tundra environments, where almost all food is obtained by men through hunting and where male mortality is high because men have to pursue mobile herds of game over long distances in a cold environment that offers few alternate sources of food.

    Steppe-tundra covered most of northern and eastern Europe during the Late Pleniglacial (25,000 to 10,000 BP). I use the term “last ice age” in order to be better understood. There was a series of ice ages during the Pleniglacial (70,000 to 10,000 BP), but modern humans had to adapt only to the last one. To date, it looks like the most visible features of Europeans (white skin, multi-hued hair and eyes) evolved during the time window of the Late Pleniglacial. If the estimates by Beleza and Canfield are to be believed, the time window is somewhere between 20,000 and 10,000 BP.

    These estimates seem to conflict with the recent findings of brown-skinned Mesolithic Europeans from Spain (7,000 BP) and Luxembourg (8,000 BP). I would argue that the changes to hair, eye, and skin color took place within a relatively restricted geographic area (essentially the plains of northern and eastern Europe) and later spread outward. It’s silly to argue that these changes must have originated in the Middle East, since the Middle East was inhabited by an African-like population until at least 12,000 BP. This population (the Natufians) shows no biological continuity with later Middle Easterners.

    • Sandgroper says:

      The recent findings also suggest a high probability that those two brown skinned Mesolithic Europeans had blue eyes.

  35. Greying Wanderer says:

    I think a lot of this La Brana thing boils down to how much weight you give the ancient writers. I give them a lot of weight but I know other people discount them completely which is fair enough. However say for the sake of argument that the pale, red haired phenotype attested to by writers from China to Egypt to Greece did exist spread from Ireland to Libya to Thrace to Ukraine to the Tarim basin. Why would the red hair mutation have spread so dramatically in the northern latitudes if it didn’t also de-pigment?

    And if the hair and skin were separate effects why would red hair decline because an improved skin lightening gene with additional features came along.

    If the ancient writers are correct and if the skin and hair are separate effects then it seems to me the La Brana conclusion requires a reason for red hair to have spread dramatically and separately.

  36. Slate Slabrock says:

    Two studies about Neanderthal DNA in modern humans came out recently.

    An interesting quote from the mainstream media coverage:

    “Both studies pinpointed parts of the genome that affect skin and hair characteristics as prime territory for snippets of Neanderthal DNA”

    Has anyone checked if SLC24A5 is one of those?

    http://www.sciencemag.org/content/early/2014/01/28/science.1245938

    http://www.nature.com/nature/journal/vaop/ncurrent/full/nature12961.html

  37. RS says:

    > Sexual selection occurs when too many of one sex have to compete for too few of the other.

    To cognize it that narrowly never crossed my mind. I admit, I could be wrong and the matter could be tricky. I really think that my account is more canonical, but we are big boys and can think for ourselves from scratch.

    To me sexual selection has occurred anytime an organism attains higher fitness (concretely, reproduces better), through getting a better mate than it otherwise might have gotten (for any counterfactual reason whatever). I would contrast this to natural selection in the strict sense, where you gain fitness by surviving better than you might have, and nurturing offspring better than you might have.

    If you are asexual your fitness is a sole function of survival and proliferation (creating and possibly nurturing offspring). What I call natural selection in the narrow sense is that which applies to the asexual taxon and the sexual taxon exactly alike. If you are sexual you also have to mind who you mate with.

    We know humans, especially women, are more appealing if their face is highly symmetric, and rather conformant to an ideal/average human face wrt hundreds of parameters. (Though some parameters must be less constrained, since you have Han and E-African women that are equally beautiful, yet wildly different looking.) Obviously to be handsome-faced in this way is advantageous in more ways than one, but it is mainly a sexual advantage, and mainly for women. Therefore I say handsomeness is mostly maintained by sexual selection, though I am open to correction. Surely plain people are not worse at survival or at nurturing offspring, per se, in abstracto. (Though on average, I think they rather likely are, which could explain why we are naturally selected to strongly prefer relatively handsome mates.)

    > Normally, the males have to compete for the females. The reverse is rare in nature.

    > Sexual selection is not the same thing as sexual preference. In other words, what you prefer is not necessarily what you will get. It all comes down to the law of supply and demand.

    Are you not a highly selective maker of economic exchanges, even though your money is limited and your economic preferences not totally satisfied?

    It seems to me women of most/all races and subraces are competing for men, and discriminating among them, and scheming to favorably impress men at large and as individuals, nearly as much as men are doing the converse vis-a-vis women. That’s what all those Jane Austen novels are largely about. This is what I would expect for a monogamous pop where both parents provide roughly equal offspring care, which is a fairly apt description of most human groups. To me it seems like you might be overestimating the import of gestation-lactation, or something like that. Sure, women bear that burden (parturition itself apparently being uncomplicated in foragers), but men bring in a lot of nutriment and also defend the family violently — for about eighteen years, if there is but one child, but more like 30 years if there are several. If you will accept a rather modest idealization, namely 100% perfect (lifelong) monogamy and no risk of male abandonment of the family, and perfectly equal care of offspring by each parent (which latter I think follows naturally from perfect monogamy and nonabandonment — but you could just postulate it if you like) . . . . . . . then I think the result will be virtually identical sexual discriminativeness in both genders, and thus equal sexual selection on both genders. I realize grain- and herd-bearing peoples in Eurasia, not to mention Africa, have been fairly polygynous, and all human pops have at least a trace of cuckoldry, so this doesn’t quite hold in actual fact — pretty close, though.

    • Sandgroper says:

      I think what you are describing is called assortative mating rather than sexual selection.

      • RS says:

        They’re not mutually exclusive. This

        > I was on the subway today and from looking around it seemed definite that sexual selection had occurred.

        could mean a lot of things, but I read it as follows: you see monogamous-type people on the street, and they are paired off assortively by overall sexual appeal. A given person won’t sleep monogamously with just anyone, and a lot of people won’t do so with the given person: because it wouldn’t be fitness-optimizing. Some person A will certainly have ‘types’ that they, idiosyncratically, find appealing — but in general people more or less agree on how appealing some person B is.

        Those who are more sexually appealing are fitter, so it is fitness-enhancing for you to marry them rather than the less-appealing. It has to be so: otherwise men and women alike would not spend titanic effort, and face risk, in trying to get a marginally-better mate, rather than pairing off randomly. Natural selection would crack down hard on this heavy effort and risk-taking if there were nothing to gain from it.

        Why are the sexually-appealing fitter? Maybe just because they will have sexually-appealing offspring — but I suspect that the appealing are also somewhat better, on average, at survival, and at nurturation of offspring (defining nurturation broadly, to include all that is good for the offspring, including male and female violence that protects it).

        Now, people sometimes act like only females are ‘choosy’, because they invest more in the offspring. Obviously in a pure promiscuous system (found in many a hummingbird, bird of paradise, mammal, etc), that could not be more true ; the male yields up some sperm and hits the road about five minutes later, good luck with everything. It’s less true in some species, where the male donates energy and security to the female while she undergoes a rather incapacitating gestation. It’s much less true in a species where the male helps care for the offspring for months or years. Less still if he is >99% monogamous, which means he cares for the offspring more intensively (since he’s not spending 15% of his energy scheming to score some extra sex on the side). It is least true of all if he belongs to a species where the male is stronger, bigger, and more belligerent, and so it falls mainly to him to defend the offspring (and territory) against predators and against hostile conspecifics, possibly even at risk to life and limb.

      • Sandgroper says:

        “They’re not mutually exclusive.” Fair point.

        In India, which is mostly populated by people rather than peacocks (which seems useful, Indians being a lot less removed from other people than peacocks are) serious gender imbalance (lots more males than females) does not result in empowerment of women, it results in them being commoditised. Razib Khan pointed that out. It doesn’t only apply to India.

        I wonder if Frosty the Snowman might be sort of right, not because the hunter got to choose the most beautiful woman, but because he got grabbed by the most aggressive woman. Women can get pretty feisty when the survival of their kids depends on it.

  38. RS says:

    BTW I agree of course that sexual selection on the female will be far greater if half the men are turning into popsicles during serial tundra camping trips, and yet few men have the ‘income’ to do polygyny. In other words your theory seems pretty good to me, to the extent that I’ve read it (more interested in your stuff on geopolitics etc).

  39. Chihuahua Hunter. says:

    I hate when HBD people start talking about history and prehistory. You guys mess up so many facts. For one Vikings were technically monogamous. Yes Viking men would have several affairs like men in Christian societies, but Viking men were ritually only married to one woman. Vikings did not have multiple wives, just one wife with many mistresses. Christianity did not change this aspect of life. You Chihuahuas are no wolves or rabbit hunters.

  40. Jaim Jota says:

    Alcohol may have something to do with the whitening of Northern peoples. If Frost is right, the relative scarcity of functional males is the force behind whitening. Men are relatively scarce in Russia, where in the last hundred years there has been a permanent deficit of men due to violence (wars, alcoholism). By coincidence, or not, Russian girls are very white and very beautiful.

    It is speculation, not based on research, but here it is permitted and somewhat encouraged.

    • Sandgroper says:

      The women in Chad and Djibouti must be an absolute knock-out.

      • asasdasdasd says:

        Yeah, I think Russian women have looked the way they have for a very long time, and Russians in general have had the same skin for a long time too.

  41. Jaim Jota says:

    If I am not drunk, which happens, Sand is insinuating that male deficit is specially severe in Chad and Djibuti. Possibly because alcohol – related violence. I lived more than a year in Lake Chad area and didnt notice gender imbalances nor drinking (it is forbidden by their religion). However, those tall shiny-black Fulani girls were cute.

    • Sandgroper says:

      Me, insinuating? Outrageous calumny, sir. I was just looking at the numbers (gender imbalance in Russia is pretty amazing, particularly for the over 65s), and noticed that, while Russia is lowest overall, Chad and Djibouti are lower in the 15-64 age range.

  42. Jaim Jota says:

    Statistics for Chad are pretty amazing, yes. They are so precise! How do they do it? Much of the population are nomad pastoralists, widely dispersed in the roadless Sahel. I wonder what proportion of the population filled and returned the census questionnaires. I never saw a male census enumerator leaving alive a nomad’s tent.

    • Sandgroper says:

      No idea, I was just trying to find a way to test your theory, and assumed whoever came up with the numbers had a rational basis for estimating them. The CIA quote similar numbers to Wikipedia.

      The ratio for Bangladesh is pretty low for the 15-64 age group. Interestingly it rises for the over 65s, which is the opposite of the trend just about everywhere for women to live longer than men. I wonder what is driving that.

  43. Jaim Jota says:

    Thank you for calling “theory” my baseless speculation. In Chad everybody knows that there are seven females for each man. When asked about the number of their wives, most declare four. Rank and honor require four and more would be lewd or immodest. BTW, what is CIA’s business counting girls in Chad?

  44. Have just been reading that though the white skin gene provides a strong advantage in northern sunless areas (vitamin D) that does not mean that there is a corresponding advantage lack of that gene in equatorial regions (assuming the owners don’t turn out too peely walli which ethiopians don’t.

    This does not in itself explain why there are the a lot of such genes so far south but it does make it much less unlikely & that the expansive pressure on the gene need not be great.

  45. Amanda Strydom says:

    Maybe we should start with the 12 tribes??

  46. anon says:

    Consider this slightly boring alternative explanation for light-skin genes:It’s not about lack of sunlight, but lack of dietary Vitamin D that prompted the shift.

    http://blogs.discovermagazine.com/gnxp/2008/01/white-skin-wheat/#.U7wfFPldV1Y

    As humans switched to low-protein agrarian diets, they lost out on Vitamin D they’re usually get from meat. The solution? Get more D from the sun.

    So it’s wasn’t really about latitude, it was about agriculture

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s