Modern humans did not begin to lighten in skin color immediately after entering Europe some 35,000 years ago. In fact, these ancestral Europeans remained brown-skinned for tens of thousands of years. This is the conclusion now emerging from studies of skin color loci.
In 2005, a team of Japanese researchers found that the depigmentation of European skin was partly due to a relatively recent allele at the SLC45A2 (AIM1) gene. They dated the allele to c. 11,000 BP and concluded that it had rapidly supplanted the original allele through positive selection (Soejima et al., 2005).
Then last year, at the Annual Meeting of the American Association of Physical Anthropologists, a molecular anthropologist at the University of Arizona, Heather Norton, presented evidence that Europeans have a similarly recent allele at another skin color gene, SLC24A5. The new allele is dated to 12,000 – 3,000 BP. As she stated during her talk: "The [evolution of] light skin occurred long after the arrival of modern humans in Europe." (Norton & Hammer, 2007).
The challenge now will be to narrow the time window. Did the change happen during the last ice age? This would be before 10,000 years ago. Or did it happen later, after hunting and gathering gave way to agriculture? This would be 7,400 to 5,900 years ago on the North European plain, where European skin is whitest (Bogucki, 1989).
Both datings are consistent with the data currently available. The corresponding explanations, however, differ greatly. If European skin whitened 7,400 to 5,900 years ago, the cause may have been a diet less rich in vitamin D and, hence, selection for lighter skin to facilitate vitamin D synthesis. This is the explanation favored by a write-up in Science:
Either way, the implication is that our European ancestors were brown-skinned for tens of thousands of years--a suggestion made 30 years ago by Stanford University geneticist L. Luca Cavalli-Sforza. He argued that the early immigrants to Europe, who were hunter-gatherers, herders, and fishers, survived on ready-made sources of vitamin D in their diet. But when farming spread in the past 6000 years, he argued, Europeans had fewer sources of vitamin D in their food and needed to absorb more sunlight to produce the vitamin in their skin. Cultural factors such as heavier clothing might also have favored increased absorption of sunlight on the few exposed areas of skin, such as hands and faces, says paleoanthropologist Nina Jablonski of PSU in State College. (Gibbons, 2007)
This explanation falls apart, however, if European skin whitened earlier, such as during the last ice age. The cause may then have been sexual selection, i.e., stronger female-female competition for male mates because of limited polygyny and high male mortality (Frost, 2006, see earlier posts here and here). Preference for lighter-skinned women is attested in a wide range of traditional, premodern societies (van den Berghe & Frost, 1986). Under conditions of intense sexual selection of women, the selective advantage of lighter-skinned women would have entailed a relative depigmentation of the entire population, both women and men.
References
Bogucki, P. (1989). The Neolithic Mosaic on the North European Plain. Updated paper originally delivered at the Society for American Archaeology meeting in Atlanta, Georgia.
http://www.princeton.edu/~bogucki/mosaic.html
Frost, P. (2006). European hair and eye color - A case of frequency-dependent sexual selection? Evolution and Human Behavior, 27, 85-103.
Gibbons, A. (2007). American Association Of Physical Anthropologists Meeting: European Skin Turned Pale Only Recently, Gene Suggests. Science 20 April 2007:Vol. 316. no. 5823, p. 364 DOI: 10.1126/science.316.5823.364a
http://www.sciencemag.org/cgi/content/summary/316/5823/364a
Norton, H.L. and Hammer, M.F. (2007). Sequence variation in the pigmentation candidate gene SLC24A5 and evidence for independent evolution of light skin in European and East Asian populations. Program of the 77th Annual Meeting of the American Association of Physical Anthropologists, p. 179. http://www.physanth.org/annmeet/aapa2008/AAPA2008abstracts.pdf
Soejima, M., Tachida, H., Ishida, T., Sano, A., and Koda, Y. (2005). Evidence for recent positive selection at the human AIM1 locus in a European population. Molecular Biology and Evolution, 23, 179-188.
van den Berghe, P.L., and Frost, P. (1986). Skin color preference, sexual dimorphism and sexual selection: A case of gene-culture co-evolution? Ethnic and Racial Studies, 9, 87-113.
Monday, April 21, 2008
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21 comments:
Also, did white people still have African hair form 20,000 years ago? Are the selection signatures for hair form similar to skin color? P2RY5 is related to hair kinkiness.
"Asian hair" definitely appears to look new (EDAR).
The recent positive selection paper for EDAR.
Long, straight hair is probably a 'derived' and relatively recent trait in Europeans, as it seems to be in East Asians. Unfortunately, I have not found any hard genetic data on this subject.
If, as Darwin argued, long head hair is a product of sexual selection, it is significant that this lengthening has occurred only in populations that have adapted to non-tropical environments, including those that have back-migrated to the Tropics, e.g., tropical Amerindians, Malays, Polynesians, and other Austronesians. This may further support the view that sexual selection of women intensified with increasing distance from the equator.
Also, did white people still have African hair form 20,000 years ago?
No. That's a hat (or at least that's the most reasonable explanation I've heard).
Compare to the finds at Dolni Vestonice, which suggest (and in the case of the male head apparently explicitly depict) long hair.
Coon suggests (thick, low density) Mongoloid hair may be an adaptation to cold.
Increased thickness--not length or straightness--has been shown to be selected for in Mongoloids. Frizzy-haired Solomon islanders have hair almost as thick as Mongoloids. Negroids have hair slightly thinner than blond Europeans.
N/A, thanks for the Dolni Vestonice link.
The male head in particular does speak to hair form at that time.
Where does the neanderthals fit in here ? They had genes for red/blond hair,and that probably means that they had light skin.Blond hair and blue eyes seems to have the exact distribution as the neanderthals once had.Is that just a coincidence ?
Jan
First,
Jewish people are the most intelligent. They win almost 40% of the Nobel Prize's and they have a small population of only 14 million. So by far they exceed the other races in intelligence. The other races having huge numbers and such small contributions.
Second,
IQ tests, test intellectual conformity, not creativity and originality. This would explain the Asian high IQ's. They as a people are the ultimate conformists.
In IQ tests there is typically only one answer to the problem. That problem being a social conformity to reason. But everyone knows that Genius's and all of the greatest developments in the world are not the product of conformity. Conformity never breeds creativity. We can see this in the lack of influence the Asian population has had on Science. China used to be called the "sick man" of Asia. Their population is massive and their contribution to innovation is almost nil. We can see this lack of originality in their adoptation of European philosophies, I.e. Communism.
Friedrich Nietzsche and other Philosophers have critized Asians. Nietsche used the words "Pallid osification" to describe Orientals.
Pallid: lacking sparkle or liveliness.
Osification: The process of becoming set and inflexible in behavior, attitudes, and actions. Inflexible conformity, rigid unthinking acceptance of social conventions.
The reality is Asian people have yet to understand that laws and rules are arbitrary. Europeans make the rules and Asian's follow them.
It also doesn't make sense that Asian's are considered smart because of the fact that they have destroyed their own countries. This is due to over-population and their basic lack of enviromental understanding.
It is also common scientific fact that women who have many children are ignorant, and those who have less children are more intelligent. This has already been proven in studies. So it seems strange to say that Asians are smart when the obviousness of their backwards countries, and medieval lifestyle makes them contrary to that premise.
Europeans have the most advanced civilizations and every other race has yet to meet these levels other than the Japanese. The Japanese only being good at copying other people's inventions and making them better. Other than that their original creativity is lacking as well. They took American cars and made them better. They took the German camera and made it better. And they took German steel and made it better. Otherwise the greatest advances still come from Europeans and Jews. Other than that the Orientals have yet to produce an Einstein or a Thomas Edison.
When it comes to Black people. It makes sense that they have low intellectual comformity, I.e. IQ tests. They are far too creative to be trapped in this unoriginal form of conditioning. You can tell their creative capacity in their athletics, music, dance, and the way they talk. They by far exceed the Asiatic races in these areas. Being better singers, musicians ect. Blacks far exceed Asians in emotive expression. In all of North America there is only one or two famous high-paid Asian actors.
Reality, Europeans rule the world and they have allowed others to exist only out of desire for economic bennifet. They, (Europeans) are also the physically strongest, winning the Strongest Man competitions again and again.
The greater the conformity, the weaker the race. Thus we see the races as they are today. The wild animal being bred out of man, and the physically impotent, conformist thriving.
Otherwise "Group psychology" is the most destructive thing in the world. All these stereotypes are false when it comes to the individual. Individualism is the most important thing for this time. All countries, Religions, groups need to dissolve for man to live in peace.
www.truenewspaper.blogspot.com
e.c. said "The Japanese ,only being good at copying "
What about the Japanese chemist who gave a lecture on a H-bomb in 1941.
He was also very early with ideas on plutonium the most secret in the world at the time so he probably couldnt copy them.
Hideki Yukawa (Nobel prize for physics 1949) studied traditional subjects like caligraphy untill he was 14. His father came home loaded with maths textbooks and apoloogised for teaching him the wrong things. Japanese culture strikes many as conformist but look how many Nobels have gone there.
Very interesting post. I also read an article that a Japanese scientist working on the Human Genome Project discovered that the pale skin is a defect or mutation but was afraid to release the information because of the sensitivity of the subject. Great Blog =)
These studies are overlooking the red hair genes that have a very ancient dates, at least two over 30,000 years old in European populations. As far as I know both lighten skin quite a bit. Combine this with the light shade you can get from 'all African' skin colour genes (my black S African relatives are a golden tan) and you'd probably be looking at an 'Asian tan with freckles' colouring with ginger hair added in.
I suspect DNA tests on ancient will probably show the incidence of ginger hair is much lower now than it was among the Cro Magnons (if they ever test for colouring). Light brown skin plus gingerness = vitamin D; but light skin plus gingerness = bad sunburn.
Also, it seems some other mutations for hair and eye colour also lighten skin tone (from Razib a while ago).
I don't think that light hair and eye colours are common as a result of sexual selection. More likely prototype skin lightening attempts.
I still suspect Neanderthal introgression as a source of these lightening genes, lack of Mt DNA and Y chromosomes really shows nothing. There seems to have been an Australoid population in South America a very long time ago, but no anomolous haplotypes have been found in the SA native population. I've also seen a couple of studies very supportive of natural selection working on human mt DNA. Makes the lack of N mt DNA meaningless.
These observations of yours don’t seem very scientific and are full of generalizations that reek of ignorance. For a blog that’s supposed to be about anthropology, the author seems to be severely lacking in knowledge on the evolution of civilizations.
You can cherrypick from a variety of different societal practices of a people and make general assumptions about them. One may argue that the strict fashion protocols in western countries is very conformist and the very individualistic fashion sense of the Japanese is very non-conformist. I could also argue that the formulaic plots of most Hollywood films is conformist while the relatively less commercial movie industries of japan and korea are non-conformist. I could go on and go on from here. But those don’t sound like very scientific assumptions do they? They are assumptions derived from my own general and somewhat limited views of either culture and my own subjective views on what conformity is.
Europeans “copy” from other Europeans and, yes, they also copy from asia. No modern society builds knowledge entirely on its own from the ground up. They integrate knowledge they learn from other societies. Science works that way. It isn’t separated by geographical boundaries. It’s shared among peoples. Very few of today’s technologies are purely European or purely asian. They build up on knowledge that’s already there. You can call that “copying” if you want but in that sense, all civilizations are copycats.
Yes china is somewhat backward today. But they were the leading civilization for centuries and until much recent history, most of Europe was backwards compared to it. Throughout the history of humanity, there isn’t one civilization that’s always on top.
I suggest that you read up on the historical contributions of ancient china. I can’t think of any educated person who would make such ignorant claims as you did here. You may be surprised to learn that the only reason you haven’t heard of any significant scientific advances from asia is because you just don’t read enough outside of the dogmatic egotistical propaganda that you like feeding yourself
Oh and my comment was directed to E.C, whom i assume is the author of this blog.
E.C,
You come across as a skinhead. Most of Asia lost out on Industrial reveloution coz they were colonized by the british, except Japan. Remember why the europeans came to asia?. Coz they were rich and more developed. Fireworks was developed in China. So does that mean Europeans are copycats, and made a bigger firework aka bomb. Silk was first used in China. All European designers use silk today in their clothes. Even pasta was first made in china. And I can go on and on. FYI in the 16th century India constituted 22% of world GDP, and China had 19% by mid 17th century. Europeans prospered part by colonization but mostly by Industrial reveloution that asia lost out.Uneducated people have more kids, that is evident in the US, europe and asia. Asia just happens to have more population that is uneducated. That was such a stupid justification on your part to claim white supremacy.It is also true that under-educated people tend to be skinheads or belong to other racist gangs.
Natural selection is still a hard concept to grasp, because the entire history of the universe is one big sequence of causality since the supposed "big bang".
I don't think you should take known diseases from the present day to explain why populations some odd years ago had to adapt. In essence, the universe is in homeostasis, until a deviation occurs.
The european apeman was just white.
Albinism is the answer whether some want to believe it or not.
"A team of scientists has tracked down a genetic mutation that leads to blue eyes. The mutation occurred between 6,000 and 10,000 years ago, so before then, there were no blue eyes... If the OCA2 gene had been completely shut down, our hair, eyes and SKIN would be melanin-less, a condition known as ALBINISM."
http://www.msnbc.msn.com/id/22934464/wid/11915773
SLC45A2: "Mutations in this gene are a cause of oculocutaneous ALBINISM type 4."
http://en.wikipedia.org/wiki/SLC45A2
The SLC24A5 gene is located on the long (q) arm of chromosome 15 on position 21.1, from base pair 46,200,461 to base pair 46,221,881.
It is currently estimated that the threonine allele became predominant amongst Europeans 5,300 to 12,000 years ago.
http://en.wikipedia.org/wiki/SLC24A5
Chromosome 15 has several other disorders that have characteristic light skin and hair.
"The OCA2 gene is located in a region of chromosome 15 that is often deleted in individuals with Angelman syndrome. A loss of this gene does not cause the characteristic features of Angelman syndrome; however, people who are missing one copy of this gene tend to have unusually light-colored hair and fair skin"
http://ghr.nlm.nih.gov/gene=oca2
The region of chromosome 15 containing the OCA2 gene is often deleted in individuals with Prader-Willi syndrome. A loss of this gene does not cause the characteristic features of Prader-Willi syndrome; however, people who are missing one copy of this gene tend to have unusually light-colored hair and fair skin
http://ghr.nlm.nih.gov/gene=oca2
"More than 70 mutations in the OCA2 gene have been identified in people with oculocutaneous albinism type 2. People with this form of albinism often have light yellow, blond, or light brown hair, creamy white skin, light-colored eyes, and problems with vision. The most common OCA2 mutation is a large deletion in the gene, which is found in many affected individuals of sub-Saharan African heritage. Other OCA2 mutations, including changes in single DNA building blocks (base pairs) and small deletions, are more common in other populations.
http://ghr.nlm.nih.gov/gene=oca2
Notice how in the last passage they specifically state "which is found in many affected individuals of sub-Saharan African heritage." but fail to name the other populations - Europeans who have "changes in single DNA building blocks (base pairs) and small deletions"
Yet below says it all:
Research done by a large team at Penn State University and a number of other institutions discovered that the gene has two primary alleles that differ in only one nucleotide, changing the 111th amino acid from alanine to threonine. [1][2][3]
The threonine allele was present in 98.7 to 100% among several European samples, while the alanine form was found in 93 to 100% of samples of Africans, East Asians and Indigenous Americans.
http://en.wikipedia.org/wiki/SLC24A5
I think this study without any doubt shows that people originally came from Black people. When I write black people I mean all non-white people. Amongst Black people we have people with straight hair and same physical features like white people, e.g. the Somalians, Nubian, Ethiopians, Aborigines, etc...
Well, this study suggest that all people came from Black people because these are the people with brown skin today. When I mean black people I refer to all non-white people.
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Come on guys, the out of Africa theory is no longer a theory, it's a fact as confirmed by the human genome project.
To make silly statements such as Caucasian or Asian phenotypes makes no sense whatsoever. You'll find these same phenotypes in Africa and in more variety. There are people with straight, curly, wavy and wooly. Within these groups some are jet black, brown, tan, white and even reddish. Are red heads non-white? Is this an adaptation for anything?
Trying to divide humans along clear racial phenotypical lines yields nothing but frustration as exceptions become far more common than the rule. For this reason, Darwin's natural selection model doesn't fit. Stop leading science with socioeconomic political biases however powerful they are.
the oldest remains of a european where the dna can show skin color is 5,300 years old in northern italy and he was white and this was before indo europeans there are over 40 remains of people with european mtdna and lived in china,siberia,kazakstan 4,000 ybp all had the gene for white skin and most had light hair and light eyes they where paler than europeans today these white europeans in aisa where indo europeans they migrated to siberia 5,300 years ago so u know for a fact 5,300 years ago there was a group of people as pale as modern swedish before before they migrated to siberia they lived in the steppes in asia 6,000 ybp as the yamn culture so u know for almost a complete fact 6,000 ybp there where people who lookied like modern swedish they where closly related to the 5,300 year old remains of a white person in italy the best way to figure out how old wite skin in europeans is to figure out who the common ancestor of those remains of people in italy and remian sif people in china are which would be defintley over 7,000 years but it is impossible to know for sure
the genetics of europe as compltley changed in the last 6,000 years british people today ar enot the same as the people who made stone henge there was not some big thing that happned 6,000 years ago that made every human in europe white thats impossble their common ancestor had white skin the indo europeans who seem to have looked like modern scandnaviens migrated to europe 5,000 ybp they had ydna r1a and r1b the naive europeans had ydna G2a and I the indo europeans slowly spread throught all of europe today most europeans haveR1b and R1a not I or G2a so the indo europeans could have made europe paler but probably not
if u put all the information togather it is impossble to say how long it has been it might be 30,000 years old no one knows but it seems like europeans or at least some hav been white like today for at least 10,000 years probably closer to 15,000 and europeans ancestors migrated to europe strting 50,000 years ago i dont know why people say 30,000 there are human remains in europe that are 45,000 years old and have mtdna U or U5 which is only in europeans today those where europeans ancestors so modenr europeans have lived in the content of europe for 50,000 yeras there are human remains in UK,Italy,Greece,Romania,SPain,France,GErmany that are over 40,000 years old europeans had covered all of europe 40,000 years ago so they first came there at least 50,000 year sago the first europeans would have been light brown skinned and had brown hair not black hair brown hair has less pigmentation than black hair europeans are really the same race as north africans and mid easterns and indians the first european would have looked like modern arabians some arabians have white skin the gene was already in europe 50,000 years ago they had less pigmentation in their hair to so 50,000 years is a long time to go from almost white skin to white skin in my opinon at least one group of people who are ancestors of modern europeans had white skin 13,000 or 15,000 years-30,000 or 40,000 years ago i would be suprised if it has only been 15,000 years sonce it is so strogly in all europeans genes even greeks who have 50% mid eastern ydna so it has had to have been a very long time
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