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From: lonetto@phri.UUCP (Michael Lonetto)
Newsgroups: net.singles,net.med,net.bio
Subject: Re: If sodomy, why not incest?(really herd behavior)
Message-ID: <2396@phri.UUCP>
Date: Mon, 21-Jul-86 16:13:59 EDT
Article-I.D.: phri.2396
Posted: Mon Jul 21 16:13:59 1986
Date-Received: Wed, 23-Jul-86 01:36:45 EDT
References: <2588@mit-eddie.MIT.EDU> <892@ucbcad.BERKELEY.EDU>
Reply-To: lonetto@phri.UUCP (Michael Lonetto)
Distribution: net
Organization: Public Health Research Inst. (NY, NY)
Lines: 30
Xref: watmath net.singles:14577 net.med:4255 net.bio:620
Summary: unmasking recessive genes

In article <892@ucbcad.BERKELEY.EDU> sadoyama@pavepaws.UUCP (Eric J Sadoyama) writes:
>
>I've heard this reasoning many times, but never any proof or evidence
>for it. How is this any different, genetically, from the situation in
>herds, or other animal living groups, where the dominant male mates with
>*all* the females in the group, be they related or not? 

Most (if not all) herding animals choose dominant males in ways that
decrease the incidence of incest.  A typical means is for females to
remain with the the herd (thus highly related) while juvenile males are
driven from the herd.  When the males are fully mature they can attempt
(individually) to take over herds, however, typically lone males wander
much further than the herd does, thus the chance of taking over one's
maternal herd is reduced.  This is a simplification of the system used
by lions.  Chimpanzees have a similar means of dealing with the problem.
I'm not familiar with how ungulates decide.

Incidentally, there is good evidence, both human and animal, that 
close inbreeding can lead to problems.  The European royal family
bred amongst itself for some centuries and managed to unmask some
unpleasant recessive genes that they were carrying, including 
hemophilia.  When any small population breeds only within itself
the frequency of homozygous recessive genotypes will increase.
Most often such genes have no  heterozygous phenotype, including
in the presence of other heterozygous recessive mutations.  Putting
two of the same recessive gene in the same person (animal, plant,
etc) causes problems.

Michael Lonetto                         UUCP:(allegra!phri!lonetto) 
USMAIL: Public Health Research Institute, 455 1st Ave, NY, NY 10016