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March 20, 2003

Hope spring forth, or does it?

Dr. Greg Cochran on the possibility of gene frequencies shifting in populations leading to changes in phenotype (eg; IQs going up and down yo-yo style over thousands of years):

Look, _nobody_ thinks about this. I'm not just talking about people who want to celebrate their ancestors' real or imagined achievements.

If you really want to understand long-range historical trends, assuming that that is even possible, you're going to have to take selection over historical time into account. Or so it seems to me.

OK, I know Greg is working on a quantitative study of Ashkenazi Jews in this context (or so I gather from his comments). Kevin MacDonald's work focuses on the group selection strategy having a eugenic effect. Does anyone know of other studies? David Sloan Wilson has done some work on Overseas Chinese (I am reading a book on what I now know is the great transnational crime racket that is the Chinese Diaspora).

I have shot-the-shit and talked to friends about possibilities that different historical experiences have had on discrete populations. Myopia for instance comes to mind (imagine a Chinese guy wearing glasses, and an Australian Aborigine wearing glasses, and reflect on which mental image seems a little ridiculous). But do these selection pressures apply anymore today? Famine is now man-made (in other world, chains of supply from surplus to deficit regions are blocked by political barriers). Many people seem to agree that for the past few generations in the modern West the "lower orders" have been more prolific.

Update: Some readers might be interested in this site: http://www.cashforbirthcontrol.com.

Posted by razib at 12:11 AM

Natural selection operates through differential reproduction of genes. It is a common misconception (propagated even by the likes of Steve Jones) that natural selection is weaker in modern man than among other animals because we now have relatively little selective mortality during the reproductively active part of the lifecycle. But of course, there might still be intense selection via differential fertility. R A Fisher was fond of pointing out that one-quarter of the population produced over one-half of the next generation (or some such impressive figure). If even half of this reproductive differential had a genetic basis, natural selection would be very strong.

Posted by: David Burbridge at March 20, 2003 09:24 AM

Of course.

Posted by: gcochran at March 20, 2003 10:29 AM

Too much emphasis is placed on "natural selection" as the only engine of Darwinism. Darwin himself talked about natural selection, sexual selection, and artificial selection.

To take one famous example, Palestinians are currently reproducing at something like 2-3 times the rate of Israeli Jews. This is shifting the demographic balance within Greater Israel at a rate that can be measured in years, not centuries. That's a form of of selection.

Posted by: Steve Sailer at March 20, 2003 08:15 PM


I wanted to replace my Norplant when it expired two years ago, and I was told they were no longer available. I checked back several times since then, and the last I heard they had decided to stop marketing them in the US.

It's just as well, I've since figured out that hormonal birth control makes me an emotional basket case.

I want to get a tubal... maybe I can borrow some crack babies and pretend they're mine, and they'll give me a tubal and some money. $200 goes a long way at Powells.

Posted by: Jacqueline at March 20, 2003 08:49 PM