Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!cs.utexas.edu!berleant From: berleant@cs.utexas.edu (Dan Berleant) Newsgroups: sci.bio Subject: Re: The Ubiquity of Tay-Sachs: a shocking but elegant theory Message-ID: <190@ghidrah.cs.utexas.edu> Date: 14 Feb 89 20:19:33 GMT References: <10276@ut-emx.uucp> Organization: U. Texas CS Dept., Austin, Texas Lines: 34 In article eric@snark.uu.net (Eric S. Raymond) writes: >In <10276@ut-emx.UUCP> ethan@ut-emx.UUCP (Ethan Tecumseh Vishniac) writes: <>>... I have... never looked into, the question of why... Tay-Sachs... has <>>such a relatively *high* incidence among Ashkenzaic Jewry (I believe that <>>1/30 individuals is heterozygous). < <>[someone] went looking for a disease or other environmental factor that was <>endemic to south central Russia and the Pripyet Marshes around the time the <>ancestors of the Ashkenazim emerged as a distinct population there. Something <>sufficiently dangerous that resistance to it was a net win over significantly <>higher infant mortality; something for which no less costly adaptation has <>been shown in any other human population; and something for which some later <>suggestion of significant resistance in the Ashkenazim could be found. <> <>He found it. A bacterium called `pasteurella pestis' -- the bubonic plague. <> <>I don't know if he ever tried controlled in vitro test of this hypothesis; in <>vivo, of course, would be horribly dangerous. But if true, it would explain <>an *awful* lot about the tragic history of the Jews in Europe. Perhaps the <>Ashkenazim really *were* (inadvertent) plague-spreaders. Standard theory about <>the ghettos escaping the worst effects because of `superior sanitation' always <>had sounded kind of thin to me. This could certainly explain the high incidence of the Tay-Sachs gene among Ashkenazim. But it wouldn't explain why Jewish ghettoes escaped the worst of the plague, because if only 1/30 of the population was resistant, that still leaves a whopping 29/30 (about 97%) who were presumably as vulnerable as the gentile population. Superior sanitation might actually be reasonable. I think Bubonic plague is carried by rats, and anything that would discourage rats would tend to reduce the amount of plague among the people in the area. Dan