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Thursday, February 28, 2008

Neanderthals and Sapiens didn't mix.


As you may know, the controversy on wether H. neanderthalensis and H. sapiens mixed on the arrival of the latter to West Asia and/or Europe did not die with the sampling of Neanderthal mtDNA that happened to be totally out of range with modern humans (while Cro-Magnons were fully in line, even if their haplogroup was somewhat exotic). A lot of people, including many scientists remain convinced that there must have existed some inter-specific sex with offsprings sufficiently viable as to produce introgression of Neanderthal genes into modern humans.

The problem is that none of such genes has been found and only theoretical models seem to support the introgression hypothesis. Last year it was discovered that, as some had fantasized, some Neanderthals had red hair... but the genetic mutation causing it was (again) totally different from that of modern humans.

Once and again the hybridist field has failed to provide any conclusive evidence of introgression, even if that has been found to be common in other species.

In Octuber 2007, J. K. Wall and S. K. Kim published in PLOS Genetics a research titled: Inconsistencies in Neanderthal Genomic DNA Sequences. It deals with two divergent studies on Neanderthal genetics, one suggesting no admixture and the other suggesting important hybridation. The authors conclude that the second study's results were only due to contamination of the Neandethal DNA and that the true Neanderthal admixture rate is 0.

4 comments:

Manjunat said...

Too bad if there is no exotic Neanderthal admixture. If nothing but for all the "ironical" stories that small Neanderthal genes, who themselves became extinct, giving unbelievable advantages to Sapiens I expect introgression.

By the way, what are the Cro-Magnon mtDNA haplogroups?

Maju said...

Welcome Manju.:)

Guess you can't say that it's 100% impossible some degree of admixtue but what I see is that evidence is lacking all the time.

The cromagnon haplogroups are N* (two samples). This was part of the first important research on ancient mtDNA, that also sampled several Neanderthals and one Paleolithic Australian. The link is:

http://www.pnas.org/cgi/content/full/100/11/6593
(Caramelli et al, 2003)

The PC graphic in that historical article shows cromagnons fully in the modern human (and European) range, Mungo Man somewhat apart but still in range, and Neanderthals very distant instead.

This mtDNA study doesn not by itself exclude introgression, though, via minimal and marginal hybridation though but it clearly determines that Neanderthals were not our direct maternal ancestors in any case.

jhangora_ki_baal said...

Maju in this edition of blogging u seemed to have expanded ur horizons....Goodluck....I would really like to read more posts about our cousins and possible ancestors "Neanderthals"...The idea of having a living neanderthal amongst us excites me...Hi Manju...

Jhangora said...

Maju did u read about "Neanderthal Treasure Trove"...I bet u must be excited...Incase you havn't read about the finding plz go to http://www.independent.co.uk/news/uk/home-news/neanderthal-treasure-trove-at-bottom-of-sea-793678.html