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From: falk@sun.uucp (Ed Falk)
Newsgroups: sci.bio,talk.origins
Subject: Re: Evolution vs.(?) Creationism
Message-ID: <10519@sun.uucp>
Date: Wed, 17-Dec-86 00:27:34 EST
Article-I.D.: sun.10519
Posted: Wed Dec 17 00:27:34 1986
Date-Received: Thu, 18-Dec-86 00:03:57 EST
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Organization: Sun Microsystems, Inc.
Lines: 39
Xref: mnetor sci.bio:67 talk.origins:223

> > I read one author who, noting that many women have given birth without
> > ever apparently having had sex, thinks that virgin birth is possible in
> > humans.
> 
> 	This seems very unlikely, because artificial stimulation of a
> mammalian egg causes development to occur only up to a certain point
> (gastrulation I think), after which it always becomes abnormal, and cannot
> proceed further.  As far as I know, the reason for this is not known; it works
> fine in many other organisms, and even occurs naturally in some (such as some
> lizards, which are near the same evolutionary path as mammals, although not as
> advanced (mammals evolved from reptiles)).
> 
There is a method called "parthogenesis" in which an egg cell is produced with
a full complement of chromosomes (instead of just 23).  The resulting child
would be a full genetic clone of the mother.  Some sci-fi stories have
been written that deal with a world where all the men have died off and the
women are perpetuating the race this way.

Biologists have figured that the odds of this happening spontaneously vary
from one in several hundred thousand to one in several hundred million.

About two decades ago, the British medical journal "Lancet" conducted a
survey to see if such a case could be found.  Testing is theoretically easy:
just do tissue cultures between mother and daughter and look for signs of
rejection.

At any rate, they got about fifty responses, most of whom could be weeded
out because they had misunderstood the article.

But when all the testing was done, they had one mother-daughter pair that
could not be told apart genetically.  It doesn't *prove* that parthogenesis
occurred, but they couldn't find any other explanation.

Sorry if the details are hazy, it's been a long time since I read about this.

-- 
		-ed falk, sun microsystems
terrorist, cryptography, DES, drugs, cipher, secret, decode, NSA, CIA, NRO.
(The above is food for the NSA line eater.)