Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!cs.utexas.edu!ut-emx!ethan From: ethan@ut-emx.UUCP (Ethan Tecumseh Vishniac) Newsgroups: sci.bio Subject: Re: The Ubiquity of Tay-Sachs: a shocking but elegant theory Summary: A fascinating response, but it left me with a few questions Message-ID: <10492@ut-emx.UUCP> Date: 14 Feb 89 15:25:00 GMT References: <10276@ut-emx.uucp> Organization: The University of Texas at Austin, Austin, Texas Lines: 32 In article , eric@snark.uu.net (Eric S. Raymond) writes: > In <10276@ut-emx.UUCP> ethan@ut-emx.UUCP (Ethan Tecumseh Vishniac) writes: > >Not being a geneticist, I have frequently wondered, but never looked into, > >the question of why an infrequent mutation like Tay-Sachs, which has such > >a devastating effect on those unfortunates who are homozygous for it, has > >such a relatively *high* incidence among Ashkenzaic Jewry (I believe that > >1/30 individuals is heterozygous). > > So he 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. .... > He found it. A bacterium called `pasteurella pestis' -- the bubonic plague. A fascinating idea, although fairly similar to the earlier suggestion about TB. However, I vaguely recall that there are two other rarer genetic diseases among the ashkenazim that produce similar metabolic effects in heterozygous individuals. (Did another poster mention this? Perhaps they could post a few more details.) In any case, the plague was widespread in Europe for quite a while. Why did the Ashkenazim come up with three genetic adaptations and other groups come up with none? Coincidence? Maybe other mutations occurred in the general population but were so diluted as to be indistinguishable from the effects of intermarrying with Jews? -- I'm not afraid of dying Ethan Vishniac, Dept of Astronomy, Univ. of Texas I just don't want to be {charm,ut-sally,ut-emx,noao}!utastro!ethan there when it happens. (arpanet) ethan@astro.AS.UTEXAS.EDU - Woody Allen (bitnet) ethan%astro.as.utexas.edu@CUNYVM.CUNY.EDU These must be my opinions. Who else would bother?