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From: emigh@ncsugn.ncsu.edu (Ted H. Emigh)
Newsgroups: sci.misc,sci.bio,soc.women
Subject: Re: Univerrsal Common Female Ancestor
Message-ID: <672@ncsugn.ncsu.edu>
Date: Sat, 10-Oct-87 22:15:39 EDT
Article-I.D.: ncsugn.672
Posted: Sat Oct 10 22:15:39 1987
Date-Received: Mon, 12-Oct-87 21:21:48 EDT
References: <894@phoenix.Princeton.EDU>
Reply-To: emigh@ncsugn.UUCP (Ted H. Emigh)
Organization: Genetics, North Carolina State University, Raleigh, NC
Lines: 35
Keywords: update on mitochondrail eve, big mama lives
Xref: mnetor sci.misc:539 sci.bio:719 soc.women:7743

In article <894@phoenix.Princeton.EDU> elturner@phoenix.Princeton.EDU (Edwin L Turner) writes:
>
>In 1983 there was a fairly extensive discussion of the above referenced
>topic started by an article I posted which I reproduce, in part, below:
>
>-All living people (or at least ~99% of them) have a single common female
>-ancestor on their purely maternal line.  In other words, tracing back to
>-one's mother's mother's mother's ... mother will bring everyone back to a
>-single individual woman.  She is estimated to have lived between 50,000 and
>-500,000 years ago.
>-
[Material left out]
>...  It
>remains true that the result suggests that our species has had at least one
>rather close brush with extinction, direct or statistical.

Just because we have common ancestors does not mean that we have had a
"close brush with extinction".  Not even close.  No more so than any other
organism on this planet.

Notice that the time from divergence was measured by the accumulation of
mutations.  It is this accumulation (among other factors) that keep the
genetic diversity of the species.  Also, remember that the size of the
human mitochondrial DNA is about 65K bases, while the entire genome is
about 3 BILLION (US Billion, really 1000 Million) bases.

While the EVE model is an interesting 'fact' it is hardly the stuff to
force us to rethink human evolution.  I teach it in my General Genetics
and Population Genetics classes to drive home the point of the extreme
difficulty in understanding MACRO evolution by completely understanding
MICRO evolution.
-- 
Ted H. Emigh, Dept. Genetics and Statistics, NCSU, Raleigh, NC
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