To: i-node who wrote (380736 ) 4/26/2008 10:36:53 PM From: combjelly Read Replies (2) | Respond to of 1574267 "CJ? You're a smart guy with numbers. What do you think caused it?" Well, Z has a point. Once China started to grow, if your area got conquered, you became Chinese regardless of whatever identity you had before. And that is a form of proselytization. Look at their respective histories. China has been more or less stable for millenia. Most Jews haven't been so lucky. Not only was the original Israel in an area that still isn't stable, they got kicked out in two waves. The last one, by the Romans, scattered Jews across the empire, into the cities where they weren't exactly welcomed with open arms. They were usually segregated into ghettos. Remember that cities weren't great places to live until the past century or two. This is illustrated by the fact that the Ashkenazi Jews have several characteristic genetic disorders that exist in a large percentage of the population. By large percentage, often several percent of the population are carriers for one or more of these. They are all autosomal recessives, which means that if you only have the gene from one parent, you are ok, even more than ok. But, if you get one from each parent, you are screwed. In the homozygous state they kill or disable in many really nasty ways. But, the heterozygous carriers often have advantages that adapt them to medieval city life. Tay Sachs, for example, gives the carriers a high immunity to tuberculosis. If I recall correctly, there are at least two more which confer similar advantages to a population that had to live in crowded, unsanitary conditions. Given this and the high prevalence of the other autosomal recessives, I suspect that they all make their own little contribution. Bottom line, there were very strong selection pressures on them. The mortality rate had to've been extremely high to drive those kind of changes.