> Paul Brandon wrote:
>
> > Homo Sapiens is remarkable homogenous, genetically speaking.
Mike Scoles replied:
>
> Then why are some some inherited diseases much more common is some
> groups than in others?
I agree with others on this thread that the message of the human
genetic code is anti-racist rather than racist. It indicates the
enormous genetic similarity of all racial groups. While certain
genes occur with greater frequency in specific populations,
surely no one can take a person's genetic code and use it to
identify his/her race with any degree of confidence.
An example concerns Tay-Sachs disease, the dreadful degenerative
disorder invariably fatal by age four. The risk of having
a child with this disorder is so much higher for Jews (I estimate
100 to 400x higher based on various sources) that it might
appear that the gene for it is a specific marker for being
Jewish. But:
1) This elevated risk only occurs among a sub-group of Jews,
those from Eastern Europe (Ashkenazim). Other Jewish groups,
notably from the Mediterranean (Sephardim) show no higher risk
than that of the general population.
2) Even for this high risk group, only about 1/25 to 1/30 carries
the gene
3) The same elevated risk as for Ashkenazi Jews is also found
among certain non-Jewish populations. One of these is a group of
French-Canadians in the Gaspe region of Quebec (Myerowitz &
Hogikyan, 1986).
So while the presence of this gene is likely to be one of the
strongest of genetic differences between Jews and non-Jews,
it's still of little help in determining who's Jewish.
Stephen
Reference
Myerowitz, R. & Hogikyan, N. (1986). Different mutations in
Ashkenazi Jewish and non-Jewish French Canadians with Tay-
Sachs disease. Science, 232, 1646--
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Stephen Black, Ph.D. tel: (819) 822-9600 ext 2470
Department of Psychology fax: (819) 822-9661
Bishop's University e-mail: [EMAIL PROTECTED]
Lennoxville, QC
J1M 1Z7
Canada Department web page at http://www.ubishops.ca/ccc/div/soc/psy
Check out TIPS listserv for teachers of psychology at:
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