A team of scientists at the University of Utah has proposed that the unusual pattern of genetic diseases seen among Jews of central or northern European origin, or Ashkenazim, is the result of natural selection for enhanced intellectual ability.
…the Utah researchers argue, evolution has had to counter a sudden threat by favoring any mutation that protected against it, whatever the side effects. Ashkenazic diseases like Tay-Sachs, they say, are a side effect of genes that promote intelligence.
…Ashkenazi Jews occupied a different social niche from their European hosts, and that is where any selective effect must have operated, the Utah researchers say. From A.D. 800, when the Ashkenazi presence in Europe is first recorded, to about 1700, Ashkenazi Jews held a restricted range of occupations, which required considerable intellectual acumen. In France, most were moneylenders by A.D. 1100. Expelled from France in 1394, and from parts of Germany in the 15th century, they moved eastward and were employed by Polish rulers first as moneylenders and then as agents who paid a large tax to a noble and then tried to collect the amount, at a profit, from the peasantry. After 1700, the occupational restrictions on Jews were eased.
As to how the disease mutations might affect intelligence, the Utah researchers cite evidence that the sphingolipid disorders promote the growth and interconnection of brain cells. Mutations in the DNA repair genes, involved in second cluster of Ashkenazic diseases, may also unleash growth of neurons.
In describing what they see as the result of the Ashkenazic mutations, the researchers cite the fact that Ashkenazi Jews make up 3 percent of the American population but won 27 percent of its Nobel prizes, and account for more than half of world chess champions. They say that the reason for this unusual record may be that differences in Ashkenazic and northern European I.Q. are not large at the average, where most people fall, but become more noticeable at the extremes; for people with an I.Q. over 140, the proportion is 4 per 1,000 among northern Europeans but 23 per 1,000 with Ashkenazim.
When I was pregnant with my second (my son), I had a really mean OBGYN who worked in the same office as my main OBGYN. The mean one sat me down in his office and told me that my son would probably have Tay-Sachs because of my Jewish (Ashkenazic) blood. My family history made it so that my son was incredibly likely to suffer from Tay-Sachs, and this doctor told me that I was a horrible mother who was risking my child’s life when I refused to take the genetic test during my pregnancy. I told him that it didn’t matter because I would have my child no matter what happened.
Now why wasn’t that doctor telling me that my son was way more likely to become a Nobel Prize winner or a genius? 😛 That would’ve been a much more pleasant conversation.
And hey, doesn’t this tie in nicely with my post about IQ and breastfeeding? No wonder I’m a breastfeeder! Its all about the Ashkenazic blood, baby! LOL.