Thursday, October 15, 2009

Sexual selection and ancestral Europeans

I have argued that sexual selection has varied within our species in both intensity and direction (men selecting women or women selecting men) (Frost, 2006; Frost, 2008). In particular, it seems to have varied along a north-south gradient with men being more strongly selected in the tropical zone and women in the temperate and arctic zones. Women appear to have been most strongly selected among humans inhabiting ‘continental steppe-tundra’. This kind of environment creates the highest ratio of females to males among individuals willing to mate—by making it too costly for men to provision additional wives and by greatly raising male mortality over female mortality through long hunting distances.

Today, tundra is generally limited to discontinuous patches of land: arctic islands and coastlines, alpine areas above the tree line, etc. Yet it is only when tundra covers large land areas that it can support large herds of migrating herbivores. Such herds can in turn support a relatively large human population, but at the cost of high male mortality—because the men have to cover long distances to seek out and follow the wandering herds.

As late as 10,000 years ago, continental steppe-tundra covered an extensive land mass, particularly in Eurasia. It was thus one of the main adaptive landscapes of modern humans during their evolution outside Africa. In particular, it might explain the unusual physical appearance of Europeans, i.e., their feminized face shape and their complex of highly visible color traits (diverse palette of hair and eye colors, depigmentation of skin color to pinkish-white).

At this point, people ask: “But why would this sexual selection play out only in ice-age Europe? What about northern Asia? There must have been lots of steppe-tundra there as well.”

There was, but it lay much further north than in Europe and was less hospitable to humans. It was all the more inhospitable because it stretched further into the heart of Eurasia and away from the warming and moistening influence of the Atlantic. Thus, the Asian steppe-tundra never supported as many humans as did the European steppe-tundra. Indeed, it seems to have been devoid of human life at the height of the last ice age (Goebel, 1999, pp. 218, 222-223).

On a map of ice-age Eurasia, the steppe-tundra belt would look like a large blotch covering the plains of northern and eastern Europe plus a narrower strip running farther north across Asia. By a geographic accident—a large mass of ice covering Scandinavia—it had been pushed much further south in Europe than elsewhere. This was where the steppe-tundra could support substantial and continuous human settlement.

When making this argument, I usually stress the word ‘continuous.’ But the word ‘substantial’ is probably more important. The larger the population, the greater the chance that interesting variants will appear through mutation:


Small populations have limited variability at any one time and low absolute incidence of mutation, and they may be subject to genetic drift. They are also likely to be narrowly localized and so more subject to rapid extinction by a regional catastrophe. … Other things being equal, the larger the population the more potential variability, at least, it is likely to have and the larger its absolute rate of mutation will be. (Simpson, 1953, p. 297)

References

Frost, P. (2008). Sexual selection and human geographic variation, Special Issue: Proceedings of the 2nd Annual Meeting of the NorthEastern Evolutionary Psychology Society. Journal of Social, Evolutionary, and Cultural Psychology, 2(4), pp. 169-191.
http://www.jsecjournal.com/articles/volume2/issue4/NEEPSfrost.pdf

Frost, P. (2006). European hair and eye color - A case of frequency-dependent sexual selection? Evolution and Human Behavior, 27, 85-103.

Goebel, T. (1999). Pleistocene human colonization of Siberia and peopling of the Americas: An ecological approach. Evolutionary Anthropology, 8, 208‑227.

Simpson, G.G. (1953). The Major Features of Evolution, New York: Columbia University Press.

21 comments:

Anonymous said...

"In particular, it might explain the unusual physical appearance of Europeans, i.e., their feminized face shape"

In what sense do europeans have a feminized face shape?

Frost, have you also considered what I mentioned once before about the UV levels of east asia and europe? You said that there's no difference in modern times, but I pointed out that this, well, only applies to modern times, and not the previous ice age. You said the difference in UV levels in the last ice age, between east asia and europe, wasn't significant. Probably, but neither is the difference in skin color between europeans and east asians. That's the key.

Anonymous said...

I also understand you're arguing against the idea that the ancestors of modern east asians didn't evolve in the extreme regions of northern asia, but it's commonly accepted that ice age east asia was more akin to the arctic, and thus more desolate, than ice age europe. Some have pointed to the fact that east asians having darker skin than europeans as a result of their being less cloud cover, but one of your theories with the case of sexual selection in east asia rested on extrapolating modern UV levels to prehistoric ones.

Tod said...

ANON. Europeans have a feminized face shape compared to what they used to look like. Heavy cloud cover is largely irrelevant as UV-B does not penetrate it but UV-A does. Vitamin D sythesis is not produced by the UV-A that gets through a blanket of clouds. The melanin in skin is there mainly for protection against UV-A and the latitude is the main factor in how intense it is. Having white skin cost Europeans it's just the payoff (for women) made it worthwhile. If it was down to an unlikely amount of cloud cover over Europe even in the months when UVB was strong enough to make vitamin D then Europeans would have evolved to maximize Vitamin D production - well they don't.( see Why are Europeans white? )



"I usually stress the word ‘continuous.’ But the word ‘substantial’ is probably more important".

As the European steppe-tundra (ST) bands would be mobile in pursuit of the same herds they'd probably be far from 'narrowly localized'. Surely they'd constantly be coming in contact with each other. The effective size of the population - being delocalized - could have been relatively large.

If there was contact with the non steppe-tundra peoples to the south then mutations that arose and disappeared in small communities outside the ST area could, once they were in a favourable environment, have quickly transformed the ST peoples.

Anonymous said...

I assumed he was reffering to europeans compared to west africans. But that makes sense, too.

"Heavy cloud cover is largely irrelevant as UV-B does not penetrate it but UV-A does. Vitamin D sythesis is not produced by the UV-A that gets through a blanket of clouds. The melanin in skin is there mainly for protection against UV-A and the latitude is the main factor in how intense it is. Having white skin cost Europeans it's just the payoff (for women) made it worthwhile. If it was down to an unlikely amount of cloud cover over Europe even in the months when UVB was strong enough to make vitamin D then Europeans would have evolved to maximize Vitamin D production - well they don't.( see Why are Europeans white? )"

I admit I've never heard of subtypes of UV rays and which ones allow vitamin D synthesis. I agree with the idea that skin color has few evolutionary benefits for humans, when one considers a whole host of other genetic traits that come into play, but this also presents a whole set of different problems for Frost- IE, why didn't so many populations capitalize on these other genetic traits to enable lighter skin on women? The closest we have to that is the khoisan, but that's it, and I'm not aware of any explanations as to why they're so incredibly light.

However, are you and Frost saying cloud cover had no effect upon UV-A? Regardless, that would still leave room from selection for UV-B due to it's poor penetration. My original critique was how Frost was extrapolating UV penetration on the modern world to the ice age era to explain the differing sexual selection for skin color among europeans, amerinds, and east asians, with his response being that the difference probably wasn't significant.

Again, true, but the skin color difference between europeans and east asians isn't significant, and in many cases, not significant for amerinds as well.

Peter Frost said...

Anon,

Do you have any references on the distribution of cloud cover during the last ice age?

"the skin color difference between europeans and east asians isn't significant, and in many cases, not significant for amerinds as well."

I don't understand the above. Could you elaborate?

Tod,

I've read a number of texts, notably Hoffecker's, that refer to this reindeer-hunting population as having a large effective size. But none of the authors have tried to estimate its total size or relative density. I eventually hope to come up with an estimate so that I can quantify the mutation rate and the intensity of selection.

Anonymous said...

"Do you have any references on the distribution of cloud cover during the last ice age?"

No, I don't. I've just often heard that ice age east asia had significantly less cloud cover than europe. You are just errenous to extrapolate modern conditions to prehistoric ones.

"I don't understand the above. Could you elaborate?"

In our email exchange, when I brought up how you were extrapolating the UV ray exposure of modern regions to their counterparts in the ice age, you said this:

"The current skin color of Inuit/Amerindians reflects selection pressures that have existed for the past 12,000 to 15,000 years. Most of that period is post-ice-age. It is doubtful that the pattern of ground-level UV has changed substantially since the last ice age."

Now that I think of it, I've overlooked what you said about the 12,000-15,000 year period, but it doesn't make much sense. Didn't the selection pressures for lightened skin occur during the ice age...?

Regardless, you say that the UV ray penetration levels for europe, east asia, and the americas probably didn't differ significantly in the ice age, which is probably true. But, neither does the average skin color difference between europeans and east asians. This is key, because the lack of a significant skin color difference lines up quite closely with the lack of a significant cloud cover difference in ice age europe and east asia, if true.

As for native americans, their case is abit different, but they've had pretty different evolutionary histories than europeans and east asians, and in many cases, the average skin color difference between them and europeans isn't significant.

Anonymous said...

I should also add that it's just not me the one who's heard of the cloud cover differences between ice age europe and east asia- your critique was going at such an idea. You have a better knowledge and grasp of this literature than I do, so perhaps you can look into it? I sincerely doubt all of these people are building such cases for cloud cover differences between the two with little to no evidence.

Tod said...

A prehistory of the north: human settlement of the higher latitudes (2005)
By John F. Hoffecker [p101]

"Climates ameliorated rapidly after 16,000- 15,000 years ago and new changes began to sweep across western Europe. Sites reappeared in northern France, Belgium, northwest Germany and southern Britain between 15,500 and 14,000 years ago. Although many of them are considered late Magdalenian, other industries emerged in the northern areas containing distinctive curve-back and tanged stone points. An emphasis on reindeer hunting persisted through a cold oscillation during 13,000-11600 years ago (Younger Dryas event). Deglaciation resumed after this cold event..."

We know than there was enough sunlight to grow the lichen that the reindeer were eating. And lichen have special adaptations to protect against excessive UVB so they are not a plant that grows in constant twilight.

Cloud cover is a sometimes thing, the serious defenders of the UV ?vitamin D theory understand that and do not mention it.

I sincerely doubt all of these people are building such cases (for cloud cover differences between the two) with little to no evidence.

If you start by assuming that European skin colour is related to UV/vitamin D and do not know much about climate then cloud cover is the obvious way to explain the anomaly of Europeans being far less pigmented than other people along the same latitude.

However north Europeans do not make any more ‘D’ with prolonged intense UVB exposure than those who evolved where the sun is strong enough to make vitamin D every day of the year. This limit would have been the first thing to be altered by natural selection if ‘D’ was wanting over a year in northern Europe. It should be remembered that north Europeans evolved where there is no UVB to provide skin synthesis of vitamin D for several months at a time. It should be obvious that the supply of vitamin D from synthesis in the sun was was always more than ample in Europe because Europeans have a mechanism that limits the amount that can be made at one time, a limit that kicks in with a mere 20 minutes European midsummer sun.

You might want to look though the previous posts.

Anonymous said...

"We know than there was enough sunlight to grow the lichen that the reindeer were eating. And lichen have special adaptations to protect against excessive UVB so they are not a plant that grows in constant twilight.

Cloud cover is a sometimes thing, the serious defenders of the UV ?vitamin D theory understand that and do not mention it."

Well, this doesn't surprise me. Like I said, it's likely that the cloud cover and UV penetration differences between ice age europe and east asia wern't significant, but to extrapolate the differences in modern times to back then is fallacious. However, this article merely mentions the frequency of reindeer hunting, and little else. You're just extrapolating it to the lichen distributions. Plus, this article bespeaks of reindeer hunting at the closure of the last ice age, when cloud cover would have been less severe.

"If you start by assuming that European skin colour is related to UV/vitamin D and do not know much about climate then cloud cover is the obvious way to explain the anomaly of Europeans being far less pigmented than other people along the same latitude."

I'm not an academic or a researcher myself. But to say that the people who research this "don't know much about climate" is extreme.

"However north Europeans do not make any more ‘D’ with prolonged intense UVB exposure than those who evolved where the sun is strong enough to make vitamin D every day of the year. This limit would have been the first thing to be altered by natural selection if ‘D’ was wanting over a year in northern Europe."

If this is true, it, again, doesn't surprise me, and doesn't do much to support Frost's thesis, as I've said- there are a significant number of other genetic traits unrelated to skin color that contribute to vitamin D synthesis, sunburn suceptibility etc. and it begs asking why there seems to be so few populations that have capitalized on this. The closest are the khoisan, but I don't know of any explanations as to why their skin is so light.

"It should be remembered that north Europeans evolved where there is no UVB to provide skin synthesis of vitamin D for several months at a time."

Are you talking about modern climactic conditions, or pre-modern ones? Just how could anyone survive in a climate, outside of dietary differences, wherein no UVB penetrates for several months at a time?

Anonymous said...

I also don't know of anyone who'd argue humans lived in constant twilight back then, which would, well, make it very hard for humans to even live back then.

Peter Frost said...

Anon,

I'll try to break this down point by point.

1. "But, neither does the average skin color difference between europeans and east asians. This is key, because the lack of a significant skin color difference ..."

This is the point that I asked you to clarify (not the issue of differences in cloud cover). I'm not sure what you mean.

2. You seem to feel that human skin color cannot change over a period of ten thousand years even when the selection pressure is strong. Have I understood you correctly?

My position is that both natural selection and sexual selection can modify skin color relatively fast if the selection pressure is strong enough. Selection is slowed down only when there is a lack of genetic variation to act on, or if there is a 'counter-selection' operating in the opposite direction.

Natural selection has a strong effect on human skin color only within the tropical zone, where it acts to maintain at least a brown pigmentation. Outside this zone, natural selection is relatively weak, and sexual selection has more freedom to modify skin color.

3. Black skin, like white skin, is something of an outlier. If you control for latitude, darkness of skin correlates highly with the incidence of polygyny. Since polygyny weakens sexual selection of women (because women are always in short supply), it may also weaken sexual selection for light skin in highly polygynous populations.

There is thus a shift in the equilibrium between natural selection for dark skin and sexual selection for light skin (as a desired female characteristic). Consequently, highly polygynous African populations are noticeably darker than weakly polygynous ones (e.g., Khoisans).

4. Finally, I must confess that I don't understand the relevance of Ice Age cloud cover to this discussion. You seem to be arguing that the difference in skin color between Europeans and other humans at similar latitudes (East Asians, Amerindians) may be due to a difference in natural selection that existed during the last Ice Age but has not existed for the last 10,000 years. Have I understood you correctly?

If, as you argue, natural selection has a strong effect on skin color even at high latitudes, why would this be so during the last ice age but not over the past 10,000 years? If this strong selection pressure has been roughly equal on Europeans, East Asians, and Amerindians for 10,000 years, why would it not have equalized their skin color?

Anonymous said...

"This is the point that I asked you to clarify (not the issue of differences in cloud cover). I'm not sure what you mean."

If you're to compare the average skin color of whites and east asians, the average isn't that different. Whites range from milky white to medium, whereas east asians range from a solid, somewhat tannish white to medium brown. I'm saying is that their average skin color differences aren't significant. That's all.

"2. You seem to feel that human skin color cannot change over a period of ten thousand years even when the selection pressure is strong. Have I understood you correctly?"

No, I never said this, and in such a regard, I don't know how you got that idea.

"My position is that both natural selection and sexual selection can modify skin color relatively fast if the selection pressure is strong enough. Selection is slowed down only when there is a lack of genetic variation to act on, or if there is a 'counter-selection' operating in the opposite direction.

Natural selection has a strong effect on human skin color only within the tropical zone, where it acts to maintain at least a brown pigmentation. Outside this zone, natural selection is relatively weak, and sexual selection has more freedom to modify skin color."

I know of your position quite well. But my qualms come on a number of fronts.

"4. Finally, I must confess that I don't understand the relevance of Ice Age cloud cover to this discussion. You seem to be arguing that the difference in skin color between Europeans and other humans at similar latitudes (East Asians, Amerindians) may be due to a difference in natural selection that existed during the last Ice Age but has not existed for the last 10,000 years. Have I understood you correctly?

If, as you argue, natural selection has a strong effect on skin color even at high latitudes, why would this be so during the last ice age but not over the past 10,000 years? If this strong selection pressure has been roughly equal on Europeans, East Asians, and Amerindians for 10,000 years, why would it not have equalized their skin color?"

Again, this relates back to our email discussion. I pointed out what seems to be a flaw in your 2008 paper- you talked of how very specific sexual selective conditions in ice age europe contributed to the lighter skin of europeans compared to east asians.

Anonymous said...

You critiqued those who spoke of climate being a strong reason for this, in the sense of differences in cloud cover, by pointing out that the differences in UV penetration between ice age europe and east asia being identical. But you were using the the UV penetration levels of modern times as a proxy for the ones in prehistoric times, and said the differences probably wern't significant. But again- that is key, because it lines up closely with climate being the primary factor for skin color differences, as the average difference between europeans and east asians in skin color isn't significant, it's moderate to slight.

However, I'm rather confused now- you're saying selection pressures came into play in the last 10,000 years? Well, obviously all sorts of ones came into play for populations across the globe, but just what kind? Brought upon by what? Acting upon what?
It seems the vast majority of the skin color differences between europeans and east asians have occured during the last ice age. I never said it was roughly equal, either. I'm saying that it lines up strongly with natural selection, better than sexual selection.

On another note, relating back to that paper, your quotes about the ideals of certain native populations in 19th century contexts correlating with european ones seem to be incomplete.

This one, for example:

"Darwin himself doubted this explanation, citing reports of European-like ideals
of beauty among West Africans, not only those of the coast but also “those of the interior
who have never associated with Europeans”:"

This is the rest of the entry: http://www.literature.org/authors/darwin-charles/the-descent-of-man/chapter-19.html

"Notwithstanding the foregoing statements, Mr. Reade admits that negroes "do not like the colour of our skin; they look on blue eyes with aversion, and they think our noses too long and our lips too thin." He does not think it probable that negroes would ever prefer the most beautiful European woman, on the mere grounds of physical admiration, to a good-looking negress.* "

And this one: "In a footnote, Darwin added that the Amerindians of Tierra del Fuego consider European
women to be extremely beautiful and that Sir Richard Burton "believes that a woman
whom we consider beautiful is admired throughout the world" (Darwin, 1936 [1888], p.
888)."

This is the full version: "The Fuegians, as I have been informed by a missionary who long resided with them, consider European women as extremely beautiful; but from what we have seen of the judgment of the other aborigines of America, I cannot but think that this must be a mistake, unless indeed the statement refers to the few Fuegians who have lived for some time with Europeans, and who must consider us as superior beings."

In fact, in this chapter, I see a very, very diverse array of standards of beauty, especially in regards to skin color. Certainly some of it might be out of fetishization (IE fuegians wanting 100% hairless faces, including brows and lashes), mistranslations, and the like, but it's significantly more variable than what you seem to allude to.

Peter Frost said...

Anon,

1. "I'm saying that their average skin color differences aren't significant. That's all."

The difference is statistically significant and easily visible. It's also significant in a broader, cultural sense, i.e., it influences how people perceive themselves and each other, e.g., the term 'pale-faces'.

2. Total (year-round) UV exposure at ground level decreases markedly with latitude. Once you get above 45 degrees north, differences in cloud cover must be very substantial to affect total UV at ground level.

And again, if the difference in skin color between Europeans and East Asians/Amerindians is somehow due to a difference in total UV exposure that existed only during the last ice age, would not the lack of difference since then have eliminated this skin color difference?

3. You're insinuating that I misrepresented Darwin's position to make it look as if he supported my views. In fact, I simply pointed out that he doubted his theory that ethnic differences in notions of beauty could explain physical differences that are apparently due to sexual selection.

To that end, I quoted those passages that indicated his doubts. I also quoted -- in the preceding paragraph -- his belief that "ideas of beauty" vary substantially from one human population to another. It's silly to imply that I selectively quote Darwin out of context to make him look like an early protagonist of my views when I argue at great length that Darwin was wrong! Please, read before you write!!

Anonymous said...

"The difference is statistically significant and easily visible. It's also significant in a broader, cultural sense, i.e., it influences how people perceive themselves and each other, e.g., the term 'pale-faces'."

If it's statistically significant, why do so many global maps maps of human skin color place east asians on pretty much on the same scale of difference as southern europeans compared to northern europeans? Plus, the term "pale-faces" is reserved as a slur for native americans only in this context. While I was off to say the difference between native americans and whites is generally the same as compared to east asians, for a considerable part of north america, it is.

"2. Total (year-round) UV exposure at ground level decreases markedly with latitude. Once you get above 45 degrees north, differences in cloud cover must be very substantial to affect total UV at ground level."

Once again, this is only in the context of modern climactic conditions, and not ice age ones. Things were significantly different back then, and the roughly moderate skin color differences between europeans and east asians would correlate strongly with it, even if it wern't. One physical trait you haven't addressed that's important to this discussion is the presence and frequencies of epicanthic folds amongst east asians and numerous other "mongoloid" peoples. Their evolutionary origins are debated, but they're generally thought to be adaptions to both extreme arctic and desert conditions, as the same adaption is seen among the khoisan and sudanese blacks. Where does the adaption come from? I'm not sure how many theories there are, but there seem to be just a few general theories, two of them lining up very closely with the lack of cloud cover in ice age east asia:

-Sun Albedo (the extra flesh around the eye protecting from this- albedo is also more significant in light sand deserts, but I'm not sure if it's comparable to the sort seen in the arctic)

-Protection from excess sunlight in a largely cloudless environment (again, so is the kalahari and the deserts of sudan)

-Protection from snow storms and sand storms, but I believe this is the least likely of them all, due to it being a rather sporadic climactic event.

And, as Tod said, UV-B doesn't penetrate cloud cover (albeit I think it might be grossly inaccurate to say it doesn't at all) but UV-A does. Thus, some considerable forms of UV rays penetrate cloud cover.

Anonymous said...

"And again, if the difference in skin color between Europeans and East Asians/Amerindians is somehow due to a difference in total UV exposure that existed only during the last ice age, would not the lack of difference since then have eliminated this skin color difference?"

This could apply to virtually any physical trait that diffrentiates the groups. If we look at a whole host of physical anthropological examinations of the remains of the ancestors of these populations at the closure of the ice age, we see that they haven't differed significantly. They have roughly the same cranio-facial structure, and general skeletal structure. Why this is, I can't explain off hand.

Looking back at your 2008 study, there's some aspects of it that are especially relevant here. Your map on incidences of polygamy indicate quite low frequencies for the whole of the americas, as well as southeast asia, and even oceania. However, the map from White doesn't indicate as to whether this was of purely modern polygamist societies or of earlier ones. Assuming it does, though, this begs asking why native americans, southeast asians, and even oceanians have remained so considerably darker so long in spite of such high frequencies of monogamy. The same also holds true for much of the middle east. In fact, your figures also show that polygamy rarely approaches even anything nearing a 100% frequency in any society, leaving a considerable portion of polygamous societies as monogamous. It begs asking why the general trend of monogamy being more in favor of the selection of women didn't occur here. I might be wrong to bring this up though, as that could just apply to societies at northern latitudes.

Plus, we see groups like southeast asians become often significantly darker than east asians, yet retaining a variety of cold adapted traits, like extensive facial flatness and prominent epicanthic folds, and still being heavily monogamous. However, in regards to what I mentioned about my lack of knowledge about White's study, I'm unaware if modern religions and the like didn't contribute to this, IE, Islam, albeit many islamic countries and societies have and do allow polygamy. But this obviously hasn't effected oceanians.

Anonymous said...

"3. You're insinuating that I misrepresented Darwin's position to make it look as if he supported my views. In fact, I simply pointed out that he doubted his theory that ethnic differences in notions of beauty could explain physical differences that are apparently due to sexual selection.

To that end, I quoted those passages that indicated his doubts. I also quoted -- in the preceding paragraph -- his belief that "ideas of beauty" vary substantially from one human population to another."

Frost, I read it perfectly. The views presented in that passage came from a variety of people, not just Darwin. I'm sorry to say but it does look like you omitted parts of the quotes to a degree. (i haven't read all of darwin's book, however.) Yes, Darwin doubted that view, and while mentioning supposed european ideals of beauty, and admiration for such traits, the full quotes, and the full passage, include viewpoints that made such ideals doubtful. You also go on to say:

"But the criteria themselves
seem to vary little among human populations. Children as young as 2-3 months old look
longer at female faces that adults have rated as attractive, be they white infants looking at
faces of black women rated by black men or black infants looking at faces of white
women rated by white men (Langlois et al., 2000; Langlois et al., 1991; Langlois et al.,
1987; Langlois & Stephen, 1977). Similar findings have been obtained with adults of
various racial/ethnic origins (Bernstein et al., 1982; Cunningham et al., 1995; Maret,
1983; Miller, 1969; Perrett et al., 1994)"

This is said in a continous line of thinking from the quotes by Darwin.

"It's silly to imply that I selectively quote Darwin out of context to make him look like an early protagonist of my views when I argue at great length that Darwin was wrong!"

But just why didn't you include the full passages, especially in face of what else I've said? You argue at length that Darwin was wrong, but consider just a few quotes of his that are criticisms of the sexual selection hypothesis.

I really hope I'm not angering or really insulting you, Frost. I really enjoy our discourses here, and hope that such things can help broaden your theories and work. I'm just calling things as I see them.

Anonymous said...

One other thing- I admit I confused something previously.

In the study you mentioned here:

https://www.blogger.com/comment.g?blogID=3734925856292601239&postID=8768141762520935918

"1.Richard Russell found that subjects could distinguish between male and female faces by the sex difference in skin tone, even when the faces had been blurred and offered no other details.
R. RUSSELL. Sex, beauty, and the relative luminance of facial features, Perception 32:1093-1107, 2003."

I thought it could have been this one: http://vdare.com/sailer/050612_blondes.htm

"I bet you assumed the one on the left is a woman and the one on the right a man.

In truth, a computer generated these images by averaging male and female faces. The only difference between them is in complexion. (The lips look more attractively feminine on the left face because of the greater contrast with the skin tone.)"

However, I googled the study and found it, and these images obviously wern't included. But I can't find anything off hand similar to what you mention. Where is it?

Peter Frost said...

Dylan Inos,

I try my best to answer queries from everyone, including high school students like yourself. In your case, I stopped answering your lengthy e-mails for several reasons.

One reason was lack of time. I have other responsibilities in life and the time I devote to you means less time for everything else.

The main reason, however, is that your "queries" (if I can use that term) are long, rambling, often incoherent, and sometimes incomprehensible. A common problem is that you accuse me of writing things that are the opposite of what I actually wrote.

I realize that English is not your first language. The real problem, however, is that you have trouble writing on an academic level, i.e., writing concisely and coherently and showing respect for the other person.

You are no longer welcome on my blog.

Robert8 said...

Peter,
From Dieneke's blog of Oktober 19, 2009 at
http://dienekes.blogspot.com/
About the mixing of incoming farmers with indigenous post-glacial people, Dieneke concludes:
"...dramatic events took place starting at the Neolithic, and that modern Europeans trace their ancestry principally to Neolithic and post-Neolithic migrants, and not to the post-glacial foragers who inhabited the continent"

My question is: I assume that your sexual selection pressure applies to the post glacial 'survivor' hunters, probably not to the incoming framers were not subjected to it in the same extent than the hunters, and did not intermix (according to several papers linked in dieneke's article), how did everybody ended up 'white'?

More generaly, how do you see your theory fits in archeogenetic theories of different european lineages coming from different places and times?

Peter Frost said...

Robert8,

Dienekes is arguing that Ice Age Europeans were demographically replaced by immigrants from the Middle East, like the Neanderthals before them.

I will deal with this subject in a later post. The main problem with his theory is that it leaves almost no time -- essentially one or two thousand years -- for Europeans, especially northern and eastern Europeans, to have evolved the physical characteristics that distinguish them from Middle Eastern populations.

This has been pointed out to Dienekes. His response is that not all Middle Easterners have black hair and brown eyes. Well, true, but the proportions are quite different. And many Middle Easterners who diverge from the black hair/brown eye phenotype are the result of gene flow from Europe at varying dates.