Open Thread: September 2011

Pavitra

If it's worth saying, but not worth its own post (even in Discussion), then it goes here.

If continuing the discussion becomes impractical, that means you win at open threads; a celebratory top-level post on the topic is traditional.

If it's worth saying, but not worth its own post (even in Discussion), then it goes here.

If continuing the discussion becomes impractical, that means you win at open threads; a celebratory top-level post on the topic is traditional.

Genetic natural selection is done operating on people. There is no need to speculate about its future effects.

We will not be done with genetic natural selection till we give up the flesh, and perhaps not even then.

In populations recently exposed to the modern diet, and ill adapted to it, there has been significant genetic adaption in a couple of generations. S. G.; Ewbank, D.; Govindaraju, D. R.; Stearns, S. C. (2009). "Evolution in Health and Medicine Sackler Colloquium: Natural selection in a contemporary human population". Proceedings of the National Academy of Sciences 107: 1787. Similarly, populations recently exposed to alcohol.

There have been significant and substantial changes in skeletal structure over the last ten thousand years. One can reasonably define the white race in such a way that it is only ten thousand years old, that everyone before then was non white, not that we know what skin color they were. In Jamaica, we are arguably seeing sympatric race formation, as the upper classes develop a significant genetic difference from the lower classes.

Ashekenazi Jews have evolved very substantial genetic differences from Sephardic Jews since the crusades, even though they have single culture, and no one discriminates between them, they have become two quite different races, a single culture, a single folk, yet two races.

Ashkenazic and Sephardic Jews were first identified as distinct less than a millenium ago. That is fast. It took tens of thousands of years for Europeans to diverge from Africans. If Ashkenazim look different from Sephardim, it's because people living in northern Europe are more likely to marry northern Europeans, and people living in the Near East are more likely to marry Arabs.

9JoshuaZ15y

There are a lot of cultural differences. Different prayers, different foods, different accents, different values, different humor, different cultural history. There also is discrimination between them if one looks at the right people who are aware of what they are looking for. This is more akin to how most Americans can't tell the difference between various East Asian populations. The genetic evidence also suggests that much of the difference between the Sephardim and Askenazim arose from the Askenazim getting an influx of European genetic material not from evolution. See this paper for example (although to be clear Askenazim do not genetically look very European compared to most Europeans).

2[anonymous]15y

Modern races or rather population groups though they have some deep roots due to archaic admixture are probably mostly rather young. For example the West African type seems to have only arisen with tropical agriculture a few thousand years ago, and has expanded its range in basically historical times (one of the reasons that until quite recently people liked to think of the Khosians as something of urhumans).