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From: felsenst@entropy.ms.washington.edu (Joe Felsenstein)
Newsgroups: sci.bio
Subject: Re: Universal Common Female Ancestor (really: Humans,Chimps,Gorillas)
Message-ID: <656@entropy.ms.washington.edu>
Date: Wed, 21-Oct-87 02:44:48 EDT
Article-I.D.: entropy.656
Posted: Wed Oct 21 02:44:48 1987
Date-Received: Fri, 23-Oct-87 03:13:14 EDT
References: <894@phoenix.Princeton.EDU> <1248@bsu-cs.UUCP> <548@bucket.UUCP> <10107@sci.UUCP> <7034@sgi.SGI.COM>
Reply-To: uw-entropy!uw-evolution!joe@uw-beaver.UUCP (Joe Felsenstein)
Organization: UW MathStat, Seattle
Lines: 41
Summary: (Humans,Chimps),Gorillas

In article <7034@sgi.SGI.COM> rmr@chefchu.SGI.COM (Robert Reimann) writes:
>In article <10107@sci.UUCP>, daver@sci.UUCP (Dave Rickel) writes:
>> 
>> I remember
>> that humans, gorillas, and chimpanzees all seem to be about equidistant from
>> some common ancestor on the evolutionary tree--that gorillas are as closely
>> related to man as they are to chimpanzees; ditto with chimps.
>> 
>
>This was a matter of contention until recent comparisions of human, chimp, and
>gorilla DNA showed that gorillas were closer, as in the diagram below.  If I
>remember correctly, the point where the gorilla/human ancestor split from
>chimps is not very far from the point where gorilla and human lines split.
> [diagram omitted]
>					 Robert Reimann.

You misremember.  Actually that's the one tree no one backs.  
The recent studies of Sibley and Ahlquist (Journal of 
Molecular Evolution, 1984) using DNA hybridization
strongly back humans being (slightly) closer to chimps than either is to
gorillas.  There are other evidences that this is true, but some studies
contradicting it and putting chimps closest to gorillas and both equidistant
from humans.  To really settle the matter more data are needed, but one
thing that is clear from all studies is that the tree is nearly a three-way
split (trifurcation).

Additional data analyses are on the way; the ones I know about back 
human-chimp.  Sibley and Ahlquist have an expanded paper coming out in
early 1988 in JME and I have a paper accompanying it analyzing this expanded
data set.

---
Joe Felsenstein, Dept. Genetics SK-50, Univ. of Washington, Seattle WA 98195
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