John Wilkins (
Mon, 22 May 1995 10:04:08 +1000

In article <>, (Gil
Hardwick) wrote:

: In article <>,
( writes:
: >No doubt, but incestuous and close cousin fertilization also greatly
: >increases the chances of the zygote's getting two copies of some
: >catastrophic recessive gene.
: For this "incest taboo" theory of yours to hold, you have to explain
: why so many isolated and otherwise culturally diverse people who know
: nothing whatsoever about either zygotes or recessive genes, hold so
: consistently nevertheless to the idea of incest being a crime.

I'm not entirely sure about the "recession" theory of incest, but a
plausible scenario is that irrespective of whatever underlying knowledge
or mythology a society may have, the *results* of close inbreeding will
tend to select culturally against the practice, so that the practice of
prohibiting inbreeding and encouraging outbreeding will be passed on to
future generations. However, this is a pretty weak selection pressure, so
I'm not sure [cf, Egyptian Pharonic sibling marriage to avoid pollution of
the royal blood]. I rather think that agricultural societies could *learn*
from observation that animals and people closely bred had unacceptable
frequencies of undesirable traits, and that this was rationalised in any
number of ways.

John "Chris" Wilkins, Assoc. Prof. of Recent Runes, Uni of Ediacara
Also: Head of Communication Services, Walter and Eliza Hall Institute
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