July 16, 2006

Cochran: A lot of apparent racial similarities are only skin deep:

Was headbutting Algerian Berber soccer star Zinedine Zidane provoked by a "racist" comment? Not being a lipreader, I'll merely point out that Zidane is slightly fairer-skinned that the Italian he flattened.

Zidane looks strikingly Teutonic because the Berbers and the Germans can reasonably be grouped in a vast Caucasian racial group with common ancestors. Similarly, East Asians and American Indians display certain similarities because they shared common ancestors back before the end of the last Ice Age.

But there are also lots of other visual or functional similarities among various groups spread far apart across the globe that are more likely caused by separate convergent evolution than by unchanging descent or by acquisition of genes through intermarriage.

Greg Cochran points out that many similarities among widely dispersed peoples are not caused by them having the same genes, but instead by having different genes that evolved to do similar things. For example, some of the sub-Saharan tribes that have high degrees of lactose tolerance have mutations giving them that capability than are different than the mutations found in the lactose tolerant northern Europeans. Or, as Cynthia M. Beall of Case Western has determined, three high altitude groups -- Andean Indians, Tibetans, and Ethiopian highlanders -- have three different adaptations that allow them to thrive at 10,000 feet or more.

Unfortunately, at present we only know what a fraction of all genes actually do, although we're learning fast.

There are a lot of other candidates for this tendency that apparent racial similarities are often only skin deep.

- For example, blonde hair is found among Caucasians and a few Australian aborigines in the center of the Outback.

- The Ainu aborigines of Japan, who have as much body hair as Robin Williams and beards like ZZ Top, were long thought by physical anthropologists to be displaced Caucasians, but genetic research has rendered that idea unlikely. They're apparently just really hairy East Asians.

- A yellowish cast to skin color is found in East Asia and among the Bushmen of Southwest Africa.

- Melanesians are often black-skinned and wooly-haired, but their neutral genes are as unlike sub-Saharan Africans as just about anybody on Earth.

- The pygmies of Central Africa and the pygmy negritos of the Andaman Islands and points East are probably not racially related.
The steatopygia of the Andamanese and the Bushmen / Hottentots women is likely convergent evolution.

On the other hand, some of these similarities could be left over from the original out-of-Africa group. Perhaps, originally all human women were fully steatopygous, and the Bushmen, some Pygmies, and the Andamanese are the only ones who didn't evolve away from that template.

My published articles are archived at iSteve.com -- Steve Sailer

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