Bosnia experienced little climactic change from 60k to 16k and Vinja Hybrids
Thursday, May 31, 2012
Was Gould a Well-Meaning but Self-Rightworthly Asshole?
he seems to have tried to destroy someone else's career due to a hatred of racism, doing so under the guise of combating scientific bias. Yet in doing so he was proved bias instead of his victim.
Source
Wednesday, May 30, 2012
Tuesday, May 29, 2012
Denisovan Admixture stretches back from 3 million years
Various reports disagree on the date the Denisovan split from the line that led to modern man, and the biggest discrepancies stem mainly from which Denisovan-like genes are being studied, and not from which dating methods were used. I propose this is because the Denisovan genome was is a giant gene dump: the Denisovan hominid was a mutt and various types of hominid in Asia were undergoing muttinization just before and at the time of Hss take-over.
Homo erectus and similar forms had lived in Asia for probably two million years. Some of their deepest DNA lineages had been separated from those that led directly to us by over 2 million years. Around 225 thousand years ago a descendant of heidelbergensis finally pushed into the coastal regions of mainland East Asia and bean to absorb the erectines there. Like his cousins in Africa that now make up only 2% of the genes there, his deepest lines had been separated from our line by some 700,000 years, while some lines may have had onlt 2-400,000 years of separation from ours.
So Asia from the Altai region all the way down to the Wallace line was undergoing heidelberg/erectus hybridization to various degrees until around 120,000 years ago when an anatomically modern homo sapien line which was, nonetheless, not descended from the line of Mitochondrial Eve entered East Asia from South Asia and supplanted/interbred with Denisovans along the Southern coasts of the mainland. By 60, 000 years ago he had made it from East Asian coast through Eastern Sundaland all the way to the southern tip of Australia, but had not fully absorbed the Denisovan populations in Western Sundaland and surrounding Islands and in the interior of China.
The Toba eruption separated eastern "Mungo Man" from the descendants of Mitochondrial Eve, who had been were pressing them east in India, and also devastated erectus populations in Sundaland. Around 40,000 ybp our ancestors, presumably with many males carrying genes ancestral to Y-haplogroup C as well as neanderthal genes from admixture in South West Asia, made it intop East Asia following the same path as Mungo Man and absorbing him as he went. This is were the early C Haplogroups got the Denisovan genes, and further studies will likely reveal that populations with a lot of Denisovan genes will also yield a higher than normal amount of genes from humans that seperated from our line after Neanderthal and Denisovan divurgence, but BEFORE the birth of Mitochondrial Eve.
In short,the Denisovan gene is a hodge-podge of of evolutionary lines that descended from South and East Asian representatives of homo erectus, heidelbergensis, neanderthal (via hybridization in the Altai region), archaic homo sapien, and possibly even "Mungo Man" and direct eastern descendants of homo georgicus.
It would be interesting to see if populations with Denisovan genes also have a high degree of Mungo Man's DNA embedded in their chromosome.
Source Blog
Iwo Eleru Is Not the 2% Archaic Content in Africans, but a neanderthal Hybrid
Since the discovery of mankind's Neanderthal and Denisovan ancestry, it has also been discovered that some Africans get as much as 2% of their DNA from an Archaic source other than Neanderthals and Denisovans.
Discoveries in Iwo Eleru of two "archaic" skulls that are dated around 13000 years ago have led some to dub the African admixture with the name "Iwo Eleru."
However, the culture that produced the Iwo Eleru skulls is definitely NOT the culture that contributed the 2% archaic genes. Here's why:
The 2% archaic admixture in Africa comes from a race that separated from our line over 700,000 years ago.
The Iwo Eleru skulls have been classified by numerous tests as being "half-way" between archaic (neanderthal, heidelberg, erectus, and archaic moderns from Israel) and modern humans. They are more "primitive" than any moderns known from Africa, but still less "primitive" than any archaic form of man. A race that dropped off the family tree 700,000 years ago anywhere even near Africa could only be Heidelbergensis (defined here as those who shared our common ancestor BEFORE the neanderthal split and AFTER the erectus/ergaster split) or a race of or related to Homo ergaster/antecedent (home erectus, as defined here, was only in Asia at the time).
Here are the clues that tell us what Iwo Eleru was:
* Nigerians have the most neanderthal blood in Africa.
* Iwo Eleru is in Nigeria
* Iwo Eleru skulls are the closest of any African skulls to skulls circa 120,000 to 80,000 BP, and these skulls are often cited as examples of early modern/neanderthal hybridization.
* The 2% archaic admixture in Africans is concentrated the highest in the pygmies of central Africa, not Nigerians
* No study has yet compared the Iwo Eleru skulls with the Ibero-maurusian skulls of North Africa, which are often said to be neanderthal/human hybrids.
* Ibero-maurusians practiced tooth-knocking, which is still practice among Nigerian tribes today.
* Ibero-maurusians appear in North Africa just after the last known neanderthals and neanderthal hybrids disappear from the fossil record in Europe...right across the Straight of Gibraltar from them in Southern Iberia.
* Morroccans, Egyptians, and Tunisians (North Africans) have the second largest amount of Neanderthal blood. The Ibero Marusians were invaded by the Capsians from the Middle East around 10,000 BC...roughly the same time as the dating of the Iwo Eleru Skulls.
It IS likely that the Iwo Eleru skulls ARE more primitive than those of the Ibero--maurusian specimens, and that would be consistent with this theory as well. If there were a population of modern humans living in west and central Africa up until the end of the last Ice Age, with a high degree of archaic genes (and some degree of archaic traits, but whose anatomy falls within the range of modern variation), then mixing with hybrid Ibero-maurusian invaders would indeed pronounce the resulting people's display of archaic features. As we can see from other late finds in Africa that show archaic traits, though much less extreme than Iwo Lereru, this was indeed the case. Admixture with neanderthal hybrids would also dilute the percentage of 700,000 year old genes in the Nigerian population...which might be why Nigerians have less "heidelberg" genes than bushmen, but more neanderthal genes than anyone else in Africa.
It would be interesting to compare the genes of Berbers, Nigerians, Basques, and Gaunches as it pertains to these ideas...
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