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From: throopw@dg-rtp.UUCP (Wayne A. Throop)
Newsgroups: sci.misc,sci.bio,soc.women
Subject: Re: Univerrsal Common Female Ancestor
Message-ID: <317@dg-rtp.UUCP>
Date: Mon, 12-Oct-87 11:30:28 EDT
Article-I.D.: dg-rtp.317
Posted: Mon Oct 12 11:30:28 1987
Date-Received: Tue, 13-Oct-87 05:43:05 EDT
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> dd@beta.UUCP (Dan Davison)
>> dhesi@bsu-cs.UUCP (Rahul Dhesi)
>>      All living people (or at least ~99% of them) have a single common
>>      female ancestor on their purely maternal line....
> A small correction:  this refers ONLY to mitochondrial DNA, not nuclear DNA,
> and so for the vast majority of the population says nothing about a single
> common female ancestor.

How does the fact that mitochondrial DNA was used in this evaluation
escape the conclusion of a single common female ancestor (SCFA for
short)?  Mitochondrial DNA comes exclusively from the female parent, and
if there was a single common original human mitochondrial DNA, it must
(barring unusually bizarre co-incidences) have come from a single female
at some point in time.  The evidence supports a single common ancestral
mitochondrial DNA, hence an SCFA.

> Nor does it imply a population bottleneck 200,000 years ago.

True.  There may have been any number of male ancestors, and the fact
that only one maternal line survived doesn't mean that it was the only
maternal line *at* *that* *time*.

> Note that the other women alive at the time could have left mitochondria
> in their descendants who did not have female offspring as recently as
> 2 generations ago, thus making it look as though there is an "Eve".  

Not only does it *look* as if there is an "Eve", there *IS* an "Eve" in
the sense meant -- that is, all *surviving* humans have an SCFA.  The
point is that the lines of descent of Eve's "competitors" may have died
out only recently, but they *DID* die out.  (Note that this Eve isn't
much like the biblical Eve, which may explain why creationists don't try
to exploit the cute naming of this hypothetical individual.)

> Note, though, that even The Sciences blew it: the cover
> says "Who was the mother of all mankind?".  Amazingly fuzzy thinking!
> I am quite amazed at the degree of misinformation this work has caused.

Um.... why is this "fuzzy thinking"?  In the sense meant, she *would* be
the mother of all mankind.  In the same sense that, say, your maternal
grandmother is the "mother of" you, your siblings, and your maternal
cousins.  It doesn't mean that she was the only female ancestor of yours
in that generation, just that she is a common one to the group of people
in question.

--
"What are we going to do?"
"S-s-s-simple," said Inigo after a while.
"Are you frightened too?" asked Fezzik in the darkness.
"Not... remotely," Inigo said with great care.  "And before, I meant to
say 'easy';  I don't know how the 's-s-s-s' got in there."

                --- from the book The Princess Bride by William Goldman