The lithic technology of southwestern France (c. 22,000-17,000 BP) strangely resembles that of the first paleo-Amerindians (c. 12,000). Some people speculate that early Europeans reached North America by crossing the Atlantic. The truth is even more incredible. Early Europeans spread eastward and became the ancestors not only of the Amerindians but also of East Asians. (source)
The recent study by Beleza et al. (2012) has elicited comment on two findings:
- European skin turned white long after
modern humans had entered Europe (c. 40,000 BP). Moreover, it whitened
relatively fast—between 19,000 and 11,000 years ago. Such a narrow
timeframe implies some form of selection, and not just relaxation of
selection for darker skin.
- The new skin-color alleles did not come from the Neanderthals. This point may have broader repercussions because some have argued that the rapidity of evolution among modern humans required “cherry picking” of useful alleles from Neanderthals and other archaic hominins.
But another
finding deserves comment. This is the discovery that an earlier (though minor)
lightening of skin color had occurred shortly after the entry of modern humans into
Europe:
[…] the initial stages of European skin lightening occurred in a
proto-Eurasian population, about 30,000 years ago, after the out-of-Africa
migration ~60,000-70,000 years ago […] and slightly more recently than the
earliest archaeological evidences for the dispersal of anatomically modern
humans in Europe, around 40,000 years ago (Beleza et al., 2012).
It’s
widely accepted that the ancestors of Europeans and East Asians parted company
long after modern humans had begun spreading out of Africa. It’s usually
assumed, however, that this splitting took place somewhere in the Middle East
or Central Asia. If we are to believe Beleza et al (2012), it must have
happened after the entry of modern humans into Europe.
So the
first Europeans were also the first East Asians. Cro-Magnon Man wasn’t just a
proto-European. He was also a proto-Eurasian.
From Africa to East Asia … by way of Europe?
A
straight line isn’t always the easiest route from point A to point B. In any
case, modern humans weren’t going anywhere in particular when they began
spreading out of Africa. They were seeking new lands and following the path of
least resistance.
Let’s
suppose you’re a band of hunter-gatherers in the Levant circa 50,000 BP. What
new territories would tempt you? The Iranian Plateau and, beyond it, the arid
steppes of Central Asia? No, that doesn’t seem very tempting.
You would
look to lands farther north and west along the Mediterranean. Those lands are similar
in climate, vegetation, and wildlife. You can continue using the same life
skills, since the means of subsistence are almost the same.
As your
descendants grow in numbers and spread farther out, they will eventually bump
up against an ecological zone that differs in climate, vegetation, and
wildlife. At that point, they’ll have to stop their advance and begin a slow
process of adaptation within transitional environments on the edge of this zone.
Once they’ve sufficiently adapted, they will break out from this “beachhead.”
And begin a new wave of advance.
This is
what happened when modern humans spread north from the Mediterranean and into
more boreal environments with wider seasonal variations. Finally, they
encountered the Eurasian steppe-tundra—a vast open plain of grassland stretching
from southwestern France to Manchuria. Living in that environment would require
a whole suite of new adaptations. The men would have to become much more mobile
in order to hunt the herds of wandering herbivores. The women would have to
abandon food gathering and take on new tasks like shelter building and garment
making. So where do you think those adaptations were developed?
In southwestern
France. This “beachhead” was the most southerly and resource-rich portion of
the Eurasian steppe-tundra (Mellars, 1985). Sheltered valleys dissected the
steppe and offered trees and other non-arctic vegetation, particularly on
south-facing slopes (Blades, 1999b). In this protected environment,
hunter-gatherers could live off salmon, local game, wild fruits, grains, and
tubers while hunting reindeer herds that passed through in the fall and winter
(Blades, 1999a; Blades, 1999b; Mellars, 1985). As the climate improved from
30,000 to 27,000 BP, closed forests became established, the herds moved further
afield, and reindeer hunting was all but abandoned at valley sites (Blades,
1999b). The men had to move out of the valleys and onto the surrounding tundra
tablelands. They now had to make further adaptations: more efficient use of raw
materials (wood for fire and shelter, lithic materials); long-distance travel to
procure them; and development of extensive social networks (Goebel, 1999; Hahn,
1987).
Sometime after
28,000 BP, they broke out from the beachhead and colonized the tundra plains in
their entirety. This breakout may correspond to a demographic expansion (23,000-21,000
BP) of a genetic lineage that occurs most often among the Basques of northern
Spain and southwestern France (Richards et al., 1996; Richards et al., 2000).
Relatively few people were involved, as indicated by the very low variability
of the northern European gene pool (Reich et al., 2001). Presumably, there were
many semi-isolated groups, each one tinkering with its own mix of cultural
adaptations until one of them got it right and colonized the Eurasian steppe-tundra.
After the breakout, nothing could stop them from spreading east
throughout the Eurasian steppe-tundra … all the way to the Pacific Ocean, and
from there to Beringia and North America. They would in time become the
ancestors of most people living today, not only Europeans but also East Asians
and Amerindians.
For this, we have several
lines of evidence:
- a
Y-chromosome study has found that all North Eurasian peoples descend from a common
ancestral population dated to about 15,000 BP (Stepanov & Puzyrev, 2000;
see also Armour et al., 1996; Santos et al., 1999; Zerjal et al., 1997).
- the
language families of northern Eurasia, particularly Uralic and Yukaghir and
more generally Uralic-Yukaghir, Eskimo-Aleut, Chukotko-Kamchatkan and Altaic,
share deep structural affinities that point to a common origin and not simply
to word borrowing (Cavalli-Sforza, 1994, pp. 97-99; Fortescue, 1998; Rogers,
1986).
- archeological
evidence (characteristic lithic technology, grave goods with red ocher, and
sites with small shallow basins) also suggests a common cultural tradition
throughout Europe and Siberia 20,000 to 15,000 years ago (Goebel, 1999; Haynes,
1980; Haynes, 1982).
- dental
and cranial remains from Mal’ta (23,000-20,000 BP) in southern Siberia indicate
strong affinities with Upper Paleolithic Europeans (Alexeyev & Gokhman,
1994; Goebel, 1999).
Finally,
the lithic technology of southwestern France (c. 22,000-17,000 BP), referred to
as “Solutrean”, strangely resembles that of the first paleo-Amerindians (c. 15,000-12,000).
Solutrean and Clovis points
share common characteristics. Both are thin and bifacial, and both share the
intentional use of the outre passé,
or overshot flaking technique, which quickly reduces the thickness of a biface
without reducing the width.
This
similarity has led to the “Solutrean hypothesis”— the idea that early Europeans
reached North America by crossing the Atlantic. Again, the easiest route
between two points isn’t always a straight line. For the proto-Eurasians of
southwestern France, the road to North America ran east ... over the unbroken
grasslands of the Eurasian steppe-tundra.
References
Alexeyev, V.P., & Gokhman, I.I. (1994).
Skeletal remains of infants from a burial on the Mal'ta Upper Paleolithic site.
Homo, 45, 119‑126.
Armour, J.A.L., Anttinen, T., May, C.A.,
Vega, E.E., Sajantila, A., Kidd, J.R., Kidd, K.K., Bertranpetit, J., Paabo, S.,
& Jeffreys, A.J. (1996). Minisatellite diversity supports a recent African
origin for modern humans. Nature
Genetics, 13, 154‑160.
Beleza, S., A. Múrias dos Santos, B. McEvoy, I. Alves, C. Martinho, E. Cameron, M.D. Shriver, E.J. Parra, & J. Rocha. (2012). The timing of pigmentation lightening in Europeans, Molecular Biology and Evolution, 20,
online
Blades, B.S. (1999a). Aurignacian settlement patterns in the Vézère valley,
Current Anthopology, 40, 712-719.
Blades, B.S. (1999b). Aurignacian lithic economy and early modern human
mobility: new perspectives from classic sites in the Vézère valley of France, Journal of Human Evolution, 37, 91-120.
Cavalli-Sforza, L.L., Menozzi, P. & Piazza,
A. (1994). The History and Geography of
Human Genes. Princeton: Princeton University Press.
Fortescue, M.D. (1998). Language Relations across Bering Strait. Reappraising the
Archaeological and Linguistic Evidence.
Cassell: London.
Goebel, T. (1999). Pleistocene human
colonization of Siberia and peopling of the Americas: An ecological approach. Evolutionary Anthropology, 8, 208‑227.
Hahn, J. (1987). Aurignacian and Gravettian
settlement patterns in Central Europe. In The
Pleistocene Old World, O. Soffer (Ed.). New York: Plenum Press, pp. 251‑261.
Haynes, C.V. (1982).Were Clovis progenitors in
Beringia? In Paleoecology of Beringia,
D.M. Hopkins (Ed.). New York: Academic Press, pp. 383‑398.
Haynes, C.V. (1980). The Clovis culture. Canadian Journal of Anthropology, 1, 115‑121.
Mellars, P.A. (1985). The
ecological basis of social complexity in the Upper Paleolithic of Southwestern
France. In Prehistoric Hunter‑Gatherers.
The Emergence of Cultural Complexity, T.D. Price & J.A. Brown
(Eds.). Orlando: Academic Press, pp. 271‑297.
Reich, D.E., M. Cargill, S. Bolk, J.
Ireland, P.C. Sabeti, D.J. Richter, T. Lavery, R. Kouyoumjian, S.F. Farhadian,
R. Ward, and E.S. Lander. (2001). Linkage disequilibrium in the human genome,
Nature, 411, 1999-2001.
Richards, M., H. Côrte-Real, P.
Forster, V. Macaulay, H. Wilkinson-Herbots, A. Demaine, S. Papiha, R. Hedges,
H.-J. Bandelt, & B. Sykes. (1996). Paleolithic and Neolithic lineages in
the European mitochondrial gene pool, American
Journal of Human Genetics, 59,
185-203.
Richards, M., V. Macaulay, E.
Hickey, E. Vega, B. Sykes, et al. (2000). Tracing European founder lineages in
the Near Eastern mtDNA pool, American
Journal of Human Genetics, 67,
1251-1276.
Rogers, R.A. (1986). Language, human
subspeciation, and Ice Age barriers in Northern Siberia. Canadian Journal of Anthropology, 5, 11‑22.
Santos, F.R., Pandya, A., Tyler‑Smith, C.,
Pena, S.D.J., Schanfield, M., Leonard, W.R., Osipova, L., Crawford, M.H., &
Mitchell, R.J. (1999). The Central Siberian origin for Native American Y
chromosomes. American Journal of Human
Genetics, 64, 619‑628.
Stepanov, V.A., & Puzyrev, V.P. (2000).
Evolution of Y‑chromosome haplotypes in populations of North Eurasia. American Journal of Human Genetics, 67,
220.
Zerjal, T., Dashnyam, B., Pandya, A., Kayser,
M., Roewer, L., Santos, F.R., Scheifenhövel, W., Fretwell, N., Jobling, M.A.,
Harihara, S., Shimizu, K., Semjidmaa, D., Sajantila, A., Salo, P., Crawford,
M.H., Ginter, E.K., Evgrafov, O.V., & Tyler‑Smith, C. (1997). Genetic
relationships of Asians and Northern Europeans, revealed by Y‑chromosomal DNA
analysis. American Journal of Human
Genetics, 60, 1174‑1183.
Hi Peter,
ReplyDeleteHave you seen this? If not, would this new info affect your conclusions here?
http://www.genetics.org/content/early/2012/09/06/genetics.112.145037
Dark skin protects against cancer.
ReplyDelete... and ...
Light skin protects against cancer. It permits the absorption of higher rates of Vitamin D which has anti-cancer properties.
White Australians (descended mainly from Brits, Scots, Irish) have high incidence of melanoma than their relatives who remained in the cloudy British Isles.
Black African-Americans who live in cloudy Northern cities have higher overall cancer rates than those who live in sunnier Southern cities.
Read all about it here:
http://www.jamesgraham.bz/cancerselectioni.html
and here:
http://cancerselection.blogspot.com
Unlike the evolution of genes over the last 25,000 years the synthesis of Vitamin D in people of white skin and dark skin is reasonably well understood and available for study. I'm going to try to explain how pigment affects vitamin D and health at temperate latitude, and why the vitamin D hypothesis of skin color does not stand up in the light of recent studies. My generalizations are staked on the gold standard authoritative source: a recent major IoM report, by experts in interpreting studies, some with a particular interest in cancer and the health of people with darker skin. (See here).
ReplyDeleteThe US and Canadian government commissioned the IoM to look at vitamin D. The vitamin D enthusiasts had worked backward from the vitamin D hypothesis to decide that, as the vast majority of people in the US do not run about outside half naked at a latitude similar to that of their ancestors (or eat a meat-rich diet) they must be vitamin D deficient. It was taken for granted that all black people in northern US latitudes would be deficient in vitamin D. Well they aren't.
""Despite the many claims of benefit surrounding vitamin D in particular, the evidence did not support a basis for a causal relationship between vitamin D and many of the numerous health outcomes purported to be affected by vitamin D intake. [...] Although ensuring adequacy is important, there is now an emerging issue of excess vitamin D intakes. A congruence of diverse data on health outcomes ranging from all-cause mortality to cardiovascular risk suggests that adverse health outcomes may be associated with vitamin D intakes that are much lower than those classically associated with hypervitaminosis D and that appear to occur at serum 25OHD levels achievable through current levels of supplement use""
The IoM looked at all the studies dealing with the epidemiology of diseases and vitamin D levels, They did not find any benefit from a higher vitamin D blood level than the one virtually every North American, including those of very dark skin color living at high latitude, already actually has. Over this practically universal level vitamin D does not improve bone health, and there is no evidence at all that vitamin D levels are causal in prevention of infectious disease or cancer, but there is evidence that people, especially black people in north America. (See here) suffer damage to their health if their vitamin D level is above this typical range for the US or Canadian population. That is not my opinion, it's the finding of the IoM in a major report.
The crucial point is that the North American population (including many who are very black) are typically not working outside wearing few clothes. They grow up and live at latitudes comparable to northern Europe's or greater, and are largely clothed during the summer. The relationship of pigment to vitamin D levels, and to health, is not one that supports the argument that the white skin (or hair and eye colors) of Europeans were caused by selection for reduction in skin pigment due to need for optinizing vitamin D levels in Europe by increased solar UVB synthesis at high latitudes in Europe (or the Pontic-Caspian steppe or Nuristan). The original UVB latitude theory as still proposed by Nina Jablonski, or the agriculture variants of Cochran and Razib Khan are wrong. There are two papers I think key to understanding the point at issue .
ReplyDeleteFirst: "...question of skin surface area and UVB exposure dose, related to erythema, necessary to achieve a given level of vitamin D status. They demonstrate the importance of baseline vitamin D status in conducting such studies. A smaller substudy suggests that skin pigment is not a barrier to vitamin D photosynthesis." Here.
Second; The determinants of serum vitamin D levels in participants in a melanoma case-control study living in a temperate climate.. It found lower vitamin D levels in fair skinned people. Only partly explained by avoiding sunburn. As the leader of the study commented "But some fair-skinned individuals also appear to be less able to make and process vitamin D in the body, regardless of how long they sit in the sun for" (Here).
LGM physical setting in the south-western Palaearctic
ReplyDeletePeter,
ReplyDeleteRazib Khan and Dienekes Pontikos's comments on this paper were that where you say "This is the discovery that an earlier (though minor) lightening of skin color had occurred shortly after the entry of modern humans into Europe", the paper does not actually show at any point that this occurred in Europe.
I know you are resistant to the idea of subsequent population change in Europe (it is certainly arguable) after the initial entry, but this is an important point...
Davidski,
ReplyDeleteAt present, the consensus among anthropologists is that there is admixture in Europe from early farmers who came from the Middle East. There were also other neolithic and postneolithic movements within Europe. The degree of admixture varies from a high of 25% to a low of 10%. The Finnish and Baltic peoples are often cited as populations with low levels of admixture.
James,
Yes, cancer rates are higher in the U.S. northeast than in the U.S. southeast. This is true for both African and Euro Americans. But we don't see this trend on the west coast. In fact, cancer rates seem to be higher in California than in Washington.
There has been much study on this point. The high cancer rates in the U.S. northeast are closely correlated, geographically, with heavy industry, particularly production of chemicals, tires, and rubber.
Sean,
Thanks for the links! Unfortunately, the vitamin D craze will be the thalidomide of the 21st century.
Anon,
I respect Dienekes and Razib Khan, but with all respect they are pushing the envelope of logic.
1. Circa 30,000 years ago, ancestral Europeans and East Asians were still a single population.
2. Modern humans were already present in Europe 40,000 years ago.
3. There is a continuity between those early Europeans and those we find at later periods.
Yes, one could jerry-rig a theoretical model whereby proto-Eurasians left Europe and then split apart somewhere else, with proto-Europeans then returning to Europe. But that is not the simplest model, to put it mildly.
Sometime after 28,000 BP, they broke out from the beachhead and colonized the tundra plains in their entirety.
ReplyDeleteIs that the Gravettian?
Unlike my earlier vitamin D comment, this is rather speculative. But, whether or not Finns are the current Europeans who are least mixed with post ice age people, I very much doubt they are more typical of denizens of the West European plain at the latter Last Glacial Maximum than Danes. The hair and eye color of Finns must the result of sexual selection of women in the latter LGM. But Finnish men look like hard bastards Compare a Finnish war hero to a Danish war hero (the only one, Denmark surrendered after 2 hours). Finns (and Baltic) men's faces seem to show less sign of sexual selection of women. That makes me think the Baltic peoples have retained some of the face shape from 25,000-21,000-BP
ReplyDeleteI think the less feminized face shape of Finns is due to the Sami admixture. Maybe of living peoples the the Sami are closest to the type of the Eurasian plain around 28,000- 21,000 BP. The Danes are closest to the Europeans of 20,000-15,000 BP, and the Finns are a mixture of types from two periods.
Peter, how dark would you say ancestral europeans were before the lightening began, and when did the light skin we see among northern europeans become commonplace?
ReplyDeletehow dark would you say ancestral europeans were before the lightening began
ReplyDeleteOlive-skinned, I would imagine.
I am no expert but the similarity of the solutreans and clovis tools looked always dubious to me.
ReplyDeleteAfter all, a stone is a stone and there must less than 10 different ways to shape a stone and make it with sharp edges, and the result will look very similar in any of these 10 diferent ways you choose.
So it could be convergent cultural behavior instead.
"the North Europeans (the Finns, Saami, and
ReplyDeleteSwedes) have diverged craniometrically the least from the CroMagnons of Europe." Here
I wonder if blue eyes are so common around Finland because of an effect other than frequency dependency that had special value in a particularly robust population suddenly under sexual selection of women. Feminization of face shape by blue eyes. Even with all the blue eyes Finns are still pretty robust. Finnish entrants for modeling competition Here.
In my opinion Danes are the current population that is closest to the appearance of people on the West European plain 11,000 years ago.
--------------
The latest refutation of the idea that vitamin D levels of 20ng/ml represents deficiency. Here.
Cranial robusticity is defined as some combination of :
ReplyDelete- a face that is large relative to the neurocranium
- a cranium with rugged and developed superstructures
- a cranial vault which is relatively thick (relative to size)
It does not mean "a relatively broad and short face" in any craniometric or anthropological context I have ever seen.
It would be interesting to see any study which places Finns as particularly robust in a world or European context, or Danes as particularly gracile.
Second-to-fourth digit ratio and facial shape in boys: the lower the digit ratio, the more robust the face.
ReplyDeleteThe vitamin D hypothesis is no longer tenable. I'm suggesting that looking to see where blue eyes are most common may still be misleading. Sexual selection may have favored blue eyes (for a feminizing effect) far more in Finnish women because they were so masculine to start with.
Finn-Baltic males were under selection for a suite of traits useful in male-male competition. Facial masculinity is respected because it is valid information about how dangerous a potential opponent is. (Hence narrow faced males get victimized and murdered even today, because their face shows them to be less dangerous.)
The corollary of superior masculinity in Finno-Baltic males, is that, in Finno-Baltic females there was a lack of femininity. And so the feminizing blue eye gene was hyper selected for in the Finno-Baltic region.
If blue eyes already had a a feminizing effect when they reached a masculine Finno-Baltic population, there must have been sexual selection of women elswhere. I think the ground zero of sexual selection was in at the western end of the European steppe tundra zone.
The 'valid information' link.
ReplyDelete> The crucial point is that the North American population (including many who are very black) are typically not working outside wearing few clothes. They grow up and live at latitudes comparable to northern Europe's or greater
ReplyDeleteYou didn't know that London and Paris are far, far north of Boston? Paris is 100 miles north of northernmost Maine, right near the Dakota-Canada line. NYC is even with Madrid and Naples, well south of Rome. DC is 50 miles up from Athens. Berlin is almost 300 miles north of the Dakota-Canada border.
I am interested in what you have to say, and you seem decently meticulous overall, but that is a pretty big factual slip.
Major European cities overlaid on North America, corrected for the identical latitude Here. 3.6 % of the Alaskan population are black. Vitamin D insufficiency in southern Arizona
ReplyDeleteSD,
ReplyDeleteYes, the Gravettian seems to correspond to this expansion onto the steppe-tundra. The Gravettians were reindeer and mammoth hunters.
Anon,
From 30,000 to 19,000 BP, early Europeans were probably as dark-skinned as Amerindians. Whitening of European skin took place between 19,000 and 11,000 BP.
Ben,
Arrowheads exist in many different human cultures, but most don't exhibit the characteristics of Clovis and Solutreans points.
Sean,
There may have been a 3-way split of the Eurasian population at the height of the last ice age, with the Saami forming a third isolate to the east of the Fennoscandian ice sheet.
It's hard to say which human group most closely resembles this original Eurasian population (since evolution is an ongoing process in all populations), but the Ainu might come closest.
Finnish women are masculine? Most of the ones I've known were babes.
Peter, same question as at the end of the last thread. What caused the shift from darkly pigmented skin to something lighter, and why hasn't it had an effect in Africa - i.e. why are African skin tones so much darker than native south American?
ReplyDeleteIt seems odd to me that a population with substantial input from a (presumably dark) ancestral Saami type, has a higher rate of blue eyes than Norwegians, and at the same the women have relatively masculine faces, when compared to Norwegian women.
ReplyDeleteAinu didn't get beards till after sexual selection had shrunk the jaws, beards are for making the jaw look bigger. (The 'valid information' paper in full text)
Finally some improved knowledge of haplogroup R1a1 (Y-DNA) (?)
Iain,
ReplyDeleteThe usual explanation is that Amerindians have a shallower time depth than subSaharan Africans, so they haven't had enough time to evolve a darker skin at tropical latitudes.
I don't think that's the whole story though. Another factor is that the dynamics of sexual selection are the reverse of what happened in Ice Age Europe. I discuss this point at greater length in the following article:
http://137.140.1.71/jsec/articles/volume2/issue4/NEEPSfrost.pdf
Sean,
Perhaps. It's late at night, and I don't really follow you.
Here’s a very thorough and illuminating study into digit ratio hera.ugr.es/doi/15009579.pdf
ReplyDeleteThere is little variance in Polish male fitness, as judged by their tight gradient digit ratios. Or, to put it another way, Poland is filled with beta males and not too many omegas or alpha male cads. Poland is a place where female monogamy is favored. The fact that Polish men also have relatively high digit ratios suggests that the men are, like their women, more favorable to monogamy.
Now compare that to Finns. Finnish men have a lot of variance in digit ratio, and a very low (masculinized) overall ratio. We can then surmise that Finland is filled with a wide variety of men (relative to their population), from omegas to betas to alphas, who are, nonetheless, more masculine than men from most other ethnic backgrounds. Finnish women would be open to alpha cad flings, cheating and using betas as emotional tampons. Presumably, some Finnish men would be glad to oblige. Both sexes would be less disposed to monogamy.
That is, at least, what a digit ratio hypothesis into sexual behavior differences would tell us. Is it true?
Polish women in Poland were much more open to “beta male game” than American women are. Polish girls love being courted in the traditional sense, don´t play “I’m the princess, here” games, and were inclined to long term relationships. They really are sweeter, more feminine and less interested in short term flings than women from other backgrounds.
And both our experiences with Polish chicks corroborate digit ratio analysis; the high overall digit ratio and low intrasex digit ratio variance of Polish girls predisposes them to LTRs and preferring the company of more attentive, “traditional” men.
My hypothesis then, based on digit ratio analysis, is that in countries where the women have a high overall digit ratio (longer index finger than ring finger) and a low intrasex variance in digit ratio (where most women and men have pretty much the same digit ratio), monogamy will be the preferred relationship norm of the women and aloof alpha male game will need to be distilled with a heavy dose of beta provider game. If my digit ratio hypothesis is correct, he will find Finnish girls to be very similar to coastal city American girls, and very different from Polish girls.
So where do modern Europeans come from then? The Middle East, Caucasus, Central Asia, etc.?
ReplyDeleteThis is a point of contention, right? I believe Greg Cochran has argued for multiple waves of complete replacement, while you, Peter, disagree with that view.
Could early American history (i.e. the European discovery and colonization of the New World) have been a replay of what had happened thousands of years before in Europe? That is, European agriculturalists replaced Amerindian hunter-gatherers in America, just as the hunter-gatherer ancestors of the Amerindians that were living in Europe were replaced by the agricultural ancestors of modern Europeans that arrived from the Mideast or wherever.
Anon asked, 'So where do modern Europeans come from then?'
ReplyDeleteLike the post says, they came from "southwestern France. This “beachhead” was the most southerly and resource-rich portion of the Eurasian steppe-tundra (Mellars, 1985)
Southwestern France is where Magdalenian Girl was found. She had the earliest known case of impacted wisdom teeth. That was caused by the face getting smaller due to sexual selection for less robust facial features.
According to this "midline diastema [a gap between two front teeth] is twice as common in blacks" [while] "it seems clear that Class II problems are most prevalent in whites of northern European descent (for instance, 25% of children in Denmark are reported to be Class II)."
West Europe had more resources and population density; sexual selection had most effect there. Look at the narrow faces with small delicate facial features (causing crowded teeth) that are commonest in West Europe. Cochran and Harpending still haven't proposed any selection pressure as the cause of the putative replacing population waves of agriculturists and/or IndoEuropeans acquiring such delicate features in the blnk of an evolutionary eye.
(My sister described my nose as like 'a butterknife'. I had 3 premolars removed when I was 12 but at 48 I still got a cyst on an impacted wisdom tooth and the irrupted neighbor, that required an operation to remove both. And without a beard my features do look very unmasculine as more than one girl has told me).
When I was young I had very pale skin -'the pint of milk' a workmate dubbed me-. Cochran & Harpending say the 'simplest explaination' for white skin in Europe is vitamin D. That is total stupidity.
IoM report on vitamin D says:
"A recent study of 182 individuals in Denmark, screened in January and February and selected to reflect wide ranges of baseline 25OHD levels and skin pigmentation, found that the increase in 25OHD levels after UVB exposure was inversely correlated with skin pigmentation as well as with baseline 25OHD (Bogh et al., 2010)."
The determinants of serum vitamin D levels in participants in a melanoma case-control study living in a temperate climate. is conclusive; light skin pigmentaion came about for reasons that had nothing to do with vitamin D.
When compared against present day populations, the ancient dna samples which have been recovered and are believed to be hunter-gatherers plot significantly more European than any existing Northern Europeans on a European-Middle Eastern ascertained axis. They don't seem particularly Amerind like (they're much more Middle Eastern like than Amerind like or Asian like).
ReplyDeleteNow, how much replacement is a point of contention - even the "high counters" of replacement still vacillate between near total replacement and 9/10s of ancestry being paleolithic in some North Eastern European populations (with 50%ish replacement as typical for Western Europe)... There is no way to be sure at the moment.
We also do not have any Middle Eastern adna samples yet, which would be a useful reference...
But it's hard to see why a lack of any evolutionary explanation for replacement has that much relevance in this context. I mean, there is adna. It is more Northern European (hyper Northern European) than present day populations, who are more Middle Eastern like. So I don't really see how the lack of an evolutionary explanation matters. As we get more adna, we will understand the extent and directions of gene flow better (whether they were only into Europe or also out of Europe).
Peter,
ReplyDeleteHave you heard about these more recent discoveries:
http://www.independent.co.uk/news/world/americas/new-evidence-suggests-stone-age-hunters-from-europe-discovered-america-7447152.html
"New archaeological evidence suggests that America was first discovered by Stone Age people from Europe – 10,000 years before the Siberian-originating ancestors of the American Indians set foot in the New World."
"The similarity between other later east coast US and European Stone Age stone tool technologies has been noted before. But all the US European-style tools, unearthed before the discovery or dating of the recently found or dated US east coast sites, were from around 15,000 years ago - long after Stone Age Europeans (the Solutrean cultures of France and Iberia) had ceased making such artefacts. Most archaeologists had therefore rejected any possibility of a connection. But the newly-discovered and recently-dated early Maryland and other US east coast Stone Age tools are from between 26,000 and 19,000 years ago - and are therefore contemporary with the virtually identical western European material."
"Another key argument for Stanford and Bradley’s proposal is the complete absence of any human activity in north-east Siberia and Alaska prior to around 15,500 years ago. If the Maryland and other east coast people of 26,000 to 19,000 years ago had come from Asia, not Europe, early material, dating from before 19,000 years ago, should have turned up in those two northern areas, but none have been found."
"Some genetic markers for Stone Age western Europeans simply don’t exist in north- east Asia – but they do in tiny quantities among some north American Indian groups. Scientific tests on ancient DNA extracted from 8000 year old skeletons from Florida have revealed a high level of a key probable European-originating genetic marker. There are also a tiny number of isolated Native American groups whose languages appear not to be related in any way to Asian-originating American Indian peoples."
Peter, you say 30-20000 circa europeans where eurasians. OK, it is consistent with the statuettes showing peper-hairs and bushman style buttock of the venuses, along with the almond shape eyes, inherited from the bushman, who are the first asians, so to speak, but
ReplyDelete1) does that imply a de-asianisation of the later post glacial-europeans, while east eurasians, i.e, today's asians, retained these characters?
2) Is there any reason west eurasians woold loose asian characters like the epicanthic fold, while east-asians retained or even amplified them. Sexual selection?
3) In this case, the Cro-magnon being more asianized than modern europeans, did they have an epicanthic fold or did they have lost it already?
Anon, study cited in your second comment has circumstantial 'key arguments'. Read post again, more carefully, here's Peter arguing against (total) replacement at Cochran and Harpending's blog
ReplyDeleteThe lack of a plausible ' evolutionary' explanation for phenomena which are anomalous for a hypothesis is only inconclusive while the science is not well understood. Once we do understand, then it's no longer tenable to make hand waving assumptions about some future discovery which will transform the field and resolve all the anomalies. The hypothesis has to be abandoned.
For example at one time interstellar travel was plausible, but now we know that it would require humans to spend hundreds of years on spaceships. Nothing we might discover about physics can change the brute facts about light speed or human lifespan. Genetic replacement is a hypotheses that is coming under pressure. It's questionable whether an informed person would still be at all confident whether its assumptions are correct.
There is only one non sexual selection explanation for impacted wisdom teeth and less robust facial features: reduced biting stress with agricultural diet. But Magdelenian girl is 13,000-15,000 years old. So what caused those who replaced Europeans to alter very quickly and look like the people they 'replaced.' Drift doesn't work that fast, so it seems the 'Replacement ' camp must argue there was some kind of selection, but instead of putting up or shutting up, they are adroitly reticent. Evasive even.
The relationship of white skin to vitamin D synthesis is a field where the important factors are already well understood. It's now known what the determinants of serum vitamin D levels are. For a significant proportion of the fair skinned, UVB exposure does not raise serum vitamin D above a (supposedly insufficient) baseline. Genetic factors which are inversely correlated with how pigmented skin is are the primary determinants of serum vitamin D levels. In other words, when exposed to sun, very light skinned Europeans get less vitamin D in serum than darker people, not more. Bogh found this, but he used UVB lamps, so his findings were not a rock solid indication of how things work in the real world. ' The determinants of serum vitamin D levels in participants in a melanoma case-control study living in a temperate climate.' supports Bogh's finding in a relevant real world solar exposure context. It's the replacement hypothesis enthusiasts who are using evolutionary explanation based 'reasoning', they're the ones working back from a cherished theory, all the while ignoring we what we actually know about real modern Europeans in relation to vitamin D.
determinants of serum vitamin D levels
ReplyDeleteThe vitamin D-agriculture /replacement hypothesis would posit a time frame for the European specific skin lightening alleles of around 7000 years ago at the earliest.. But the date for the for the European specific skin lightening alleles is actually 19,000 to 11,000 years ago. Peter 's theory that the white skin of today's Europeans evolved in a period of intense sexual selection (in Europe) that occurred 20,000-15,000 BP, had very little to support it at first. The vitamin D hypothesis is finished, the mtDNA case for replacement was badly weakened by the above study. The timing of skeletal changes (such as impacted teeth), along with the skin lightening gene dates converge on one conclusion. A bad theory does not get studies flying to its aid from every quarter.
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Redness enhances perceived aggression, dominance and attractiveness in men's faces.
Comprehensive candidate gene study highlights UGT1A and BNC2 as new genes determining continuous skin color variation in Europeans. "We identified two new skin color genes: genetic variants in UGT1A were significantly associated with hue and variants in BNC2 were significantly associated with saturation"
UGT1A polymorphisms in a Swedish cohort and a human diversity panel, and the relation to bilirubin plasma levels in males and females. "Testing for the association of genotype and total bilirubin levels (nonfasting) in plasma disclosed that homozygous carriers of the TA allele, irrespective of haplotype combinations, had increased levels of bilirubin compared with noncarriers, but a gender-associated difference was observed."
Ovarian cancer-associated polymorphisms in the BNC2 gene among women with endometriosis.
Read post again, more carefully, here's Peter arguing against (total) replacement at Cochran and Harpending's blog
ReplyDeleteI'm not talking about mtdna evidence, for which a selective argument may be plausible. These are markers across the entire autosome from adna.
http://dienekes.blogspot.co.uk/2012/04/ancient-dna-from-neolithic-sweden.html
http://dienekes.blogspot.co.uk/2012/06/mesolithic-iberians-la-brana-arintero.html
http://dienekes.blogspot.co.uk/2012/03/first-look-at-genome-of-tyrolean-iceman.html
These are all subsequent to that whole discussion between Peter and Greg. Read up if you're not aware.
You have to consider this in light of the latest evidence...
Particularly of interest to you would be that the more narrow faced Western Europeans show less "paleolithic" (apparently) ancestry than the wider faced Eastern Europeans.
I'll take your word for it.
ReplyDeleteThe mtDNA has been further called into question just last week. Though I don't know about genetics, the markers across the entire autosome from adna, it will prove no more reliable.
I know this because what is being said about white skin, vitamin D and craniofacial form is nonsense (and about vitamin D, I do know). Thats what was meant by saying 'The lack of a plausible evolutionary explanation for phenomena which are anomalous for a hypothesis is only inconclusive while the science is not well understood. Once we do understand, then it's no longer tenable to make hand waving assumptions about some future discovery which will transform the field and resolve all the anomalies. The hypothesis has to be abandoned.'
:shrugs:
ReplyDeleteyour faith is perhaps admirable, but looking at adna directly, and particularly at the pigmentation mutations there, will give us irrefutable information about gene flow to Europe, and the timing of pigmentation changes. More so than cobbling together a bunch of random studies that you feel support your favored theory. shame you don't have any interest.
The first key idea is that evolution optimizes function. It makes things ... It magnifies the rare changes that improve things (G.Cochran)
ReplyDeleteI have faith in Gregory Cochran. It is strange indeed for the author of a book about the EXPLOSION in selection during the last last 10,000 years to, in effect, argue that very transition to agriculture didn't involve a process of picking up hyper-marginal genes and running with them, thereby transforming the genome of the hunter gatherers beyond all recognition.
You know. Magnifying 'the rare changes that improve things'. And being necessarily extremely rare during hunter gatherer times (when they were not adaptive), it would be possible for these rare genes to happen to be present in the samples of adna from hunter gatherer times that we have. But them not being there, in the relatively few samples we have, is far from proof that they were alien to Europe.
Citing (Melchior et al., 2010), Peter's rejoinder to Cochran was "So the sharp genetic divide was not between late hunter/fisher/gatherers and early farmers. It was between the earliest farmers and groups that had been farming for at least a millennium. The evidence points to natural selection and not to population replacement."
mtDNA is selected very very slowly (many still claim it's not selected at all). If Euro HG mtDNA was in the earliest farmers and disappeared over the next thousand years, is it really so difficult to believe that other DNA (which evolves far more rapidly) could alter drastically?
Breeding fruit flys for simple longevity there were changes in all sorts of genes found:here. The myriad challenges of agriculture would have transformed the genome.
The Pontic-Caspian steppe is at the eastern edge of the west European plain; why would anyone be surprised at European hair and eye color genes being in the Kurgan homeland, Nuristan, or Manchuria by the Neolithic.
White skin has nothing to do with vitamin D and/or agricultue, it appeared between 19,000 and 11,000 years ago in ancestral Europeans only. Moreover many Europeans have weak features, to the extent that their faces are too small for their teeth, and we know this was true 13,000 years ago, so it wasn't caused by reduced need for chewing with an agricultural diet.
It is hand waving to ignore these salient facts and point to the discrepancy between the pre agricultural and the current European genomes.
Feminine women would be more impacted by female hormones, and reproductive system cancers are caused by such hormones right? Europe has the highest rates of breast and ovarian cancer, and Denmark has the highest of all.
Scroll up a bit on this page to linked study 'Comprehensive candidate gene study highlights UGT1A and BNC2 as new genes determining continuous skin color variation in Europeans. ' that says "We identified two new skin color genes: genetic variants in UGT1A were significantly associated with hue and variants in BNC2 were significantly associated with saturation" Also linked above on this page is the study 'Ovarian cancer-associated polymorphisms in the BNC2 gene among women with endometriosis.'
Now do you see.
If Euro HG mtDNA was in the earliest farmers and disappeared over the next thousand years, is it really so difficult to believe that other DNA (which evolves far more rapidly) could alter drastically?
ReplyDeleteFirstly, about this comment of Peter's that "the sharp genetic divide was not between late hunter/fisher/gatherers and early farmers" it is based on a paper which states "A high frequency of Hg U lineages , especially U5, has been inferred for pre-Neolithic Europeans based on modern mtDNA data, with Hg U5 being fairly specific to Europe.". I have no clue why this "inference" is given by him superior status to actual mtdna from bones that were actually buried in the ground at that time.
Secondly, as far as I am aware, yes it is. The largely neutral autosome is not going to evolve to match more closely the Middle Eastern genome by natural selection. It's not going to happen.
A selective story is dubious but believable for mtDNA. It's not plausible at all for the autosome. We're not talking introgressing variants or selective sweeps here.
I don't think you'll find anyone who believes a selective story is plausible, or that the increased similarities could evolve by chance or drift. I have never seen any genome blogger or published paper ever remotely suggest that selection or drift is a plausible explanation at all.
I think the link on Rose's fruit fly experiment suggests there would be drastic changes, again Natural Selection Cuts Broad Swath Through Fruit Fly Genome "In addition, soft sweeps could explain the apparent speed of human evolution, because they work on the genetic variation already present in a population, without having to wait for a novel mutation to arise."
ReplyDeletePeter is maintaining his hypothesis, I would note the vitamin D evidence seemed to refute his ideas, but lo and behold he has already seen off the vitamin D objection.
The best thing to have is a good theory, not a bunch of bien pensant supporters. We shall see.
"I have no clue why this "inference" is given by him superior status to actual mtdna from bones that were actually buried in the ground at that time."
ReplyDeleteAnon,
The study by Melchior et al. was based on mtDNA from bones.
QUOTE="But Finnish men look like hard bastards Compare a Finnish war hero to a Danish war hero (the only one, Denmark surrendered after 2 hours). Finns (and Baltic) men's faces seem to show less sign of sexual selection of women. That makes me think the Baltic peoples have retained some of the face shape from 25,000-21,000-BP"
ReplyDeleteIf Danes cant fight please explain the viking age. Perhaps they just realized the Nazis made better masters than the Soviets.
'Anglo Saxons' did very little real fighting Bishop Wulfstan complained Saxon lords often looked on and did nothing as their wife and daughters were gang raped by Vikings.
ReplyDeleteThe Viking age was caused by a special situation that forced Danish men to be aggressive; female infantide caused an excess of males in their society, there was a youth bulge disproportionately made up of young men.
Remember that the eastern 'English' suffering Viking attacks were to a great extent ethnically Danish. The 'Anglo Saxon' Jutes (Jutland) the Angles (Angeln) via Fresia. 'Saxon' England,
Denmark is the most tender minded minded country in the world; more accepting of homosexuality (Vikings had sex with one another on the longboats BTW) than any other state, homosexuality was legalised in 1933, the age of consent is 15, first country to legalize same sex unions. It goes overboard on sustainable energy "the Danish Government has set a goal of running the entire country on renewables by 2050. What makes Denmark's announcement even more unusual is that it has won support from across the country's political spectrum" Here.
Denmark scraps fat tax after it emerges people were travelling across the border in search of cheaper unhealthy snacks Nanny state.
A modern Viking Danish protester: 'No one would care if a Palestinian was hit with a rifle' "While volunteering for the International Solidarity Movement (ISM) in the West Bank over the past six weeks, Ias says he has witnessed "a process of ethnic cleansing that has been going on since the start of the occupation".
The Danish psyche is as far from being sympathetic to Nazi ideals as it is possible to get.
As the pigmentation mutations that lighten Europeans and Asians are different and not shared. If Asians only separated 20kya in France that implies that there ancestors the Cromagnons were as dark as Negroes up to that time.
ReplyDeleteSean the vikings did not only invade England they also made conquest in France, North Africa and over round headed slavs in Russia.
First point, no. The original skin color in Sub Saharan Africa can be seen in surviving hunter gatherer peoples. The Bushmen who are known to be basal to all other populations of modern humans are far lighter than Black Africans. (Peter's ideas about why Black Africans are so dark here).
ReplyDeleteCromagnons got lighter but prior to 19,000 years ago no humans were white.
Second point. One could speculate that the Danish contributed the traits that made England's invention of the modern world possible. The US too, the Puritans who went to New England were disproportionately from East Anglia, the most Danish part of England.
ReplyDeleteBut then...who are middle easterners and south asians descended from? they seem to cluster closer to europeans than modern east asians do in principal component analyses.
ReplyDeleteSo... were the Clovisolutrean settlers of the new world, bronze or white? If they took the steppe-tundra route, we'd have to assume bronze. But if they crossed water (Solutreans had boats), perhaps skirting the edge of a winter transatlantic icepack, maybe white Clovisolutreans hit North America first...
ReplyDelete...which would explain numerous Native American legends, of their ancestors encountering the prior inhabitants of the land -- "white giants" -- some described as blue eyed or red headed.
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ReplyDelete