Wednesday, June 11, 2014

Neanderthal Admixture and Racial Phenotypes In Modern Humans

Analysis of the recovered ancient Neanderthal genome strongly suggests that they had very light pigmentation in hair, skin and eyes.  Put simply, Neanderthals were white.  Ancient DNA also suggests that the earliest modern humans in Europe, called Cro-Magnons, were dark pigmented relative to modern Europeans.  Simply put, Cro-Magnons were "brown" (but did not have the modern sub-Saharan African phenotype, associated with the folk racial classification "black" in the United States, either).

The questions is whether light pigmentation in some modern humans in Eurasia arose from admixture with Neanderthals.  The Neanderthal light pigmentation genes aren't identical to the modern European light pigmentation genes, but a new paper makes a tentative case that most of the light pigmentation genes in aboriginal Tawainese people, and to a much lesser extent in some other Eurasians (especially East Asians), could have a Neanderthal source.

I'm agnostic regarding how solid this evidence is at this time.  Maybe the paper makes a really strong case for this, but I'm not convinced by what I have read summarizing the paper so far.

2 comments:

andrew said...

There is no genuine dispute that skin color, hair color, eye color, and other similar aspects of personal appearance are governed by genes. Nor is there reasonable dispute that geographic origins and genetically governed aspects of appearance are strongly correlated.

Only willful blindness can prevent someone from distinguishing between someone ancestrally from Democratic Republic of Congo from someone ancestrally from Norway from someone ancestrally from coastal China.

Reference to folk racial classifications, which has some relationship to genotype despite not coinciding exactly, are reasonable ways of communicating the gist of those regional distinctions. Folk classifications of race have problematic boundaries and issues, but they aren't totally divorced from reality either.

terryt said...

"Only willful blindness can prevent someone from distinguishing between someone ancestrally from Democratic Republic of Congo from someone ancestrally from Norway from someone ancestrally from coastal China".

Well put.

"The questions is whether light pigmentation in some modern humans in Eurasia arose from admixture with Neanderthals".

I have always been strongly inclined to the view that Neanderthals were light pigmented. And that to at least some degree the modern light-coloured gene introgressed from Neanderthals. After all, in the case of most species a white colour is associated with camouflage in Winter snow, exactly the condition many Neanderthal populations were exposed to. However parts of the study are difficult to explain. Such as:

"most of the light pigmentation genes in aboriginal Tawainese people"

I didn't know there were any 'light pigmentation genes in aboriginal Tawainese people'.