Re: Dating Adam

Terry M. Gray (grayt@calvin.edu)
Tue, 28 May 1996 13:18:10 -0400

Glenn wrote:

>Agreed. But due to some recently discovered problems with the methodology,
>"Eve" may have been much longer ago than you seem to want (~100,000
>years). Christopher Willis writes:
>
> "The most probable divergence time between the ancestors of humans
>and chimpanzees, it is now thought, lies somewhere between four million
>and seven and a half million years ago. When I used transversions alone
>to estimate the age of Eve, I found that humans had accumulated about
>one-seventh as many transversions as had accumulated between us and the
>chimpanzees. This meant that the mitochrondrial Eve probably lived
>between six hundred thousand and a million years ago."~Christopher Wills,
>The Runaway Brain, (New York: Harper Collins, 1993), p. 54-55 (see also
>Trinkaus and Shipman The Neanderthals, 1992 p. 396)
>
>If genetics now seems to imply an Eve of approximately 800,000 years ago,
>then "Eve" was a Homo erectus. Anatomically modern men appear around
>130,000 years ago.
>

Glenn,

I mentioned that the dating has been controversial. I think that the
position that you are citing is a minority position. Most of the data --
mitochondria, Y-chromosome, other chromosomal loci etc. are pointing to a
much younger date -- obviously given certain assumptions about the clock --
are pointing to dates as young as 80,000 years ago all the way to 200,000
years ago with 120,000 years ago being the most commonly cited number.
This is much more compatible with the anthropological data giving the
appears of modern homo sapiens at 130,000 years ago.

Most of the advocates of the older data are also advocates of the
multi-regional origin hypothesis. I.e. that modern man "independently"
arose from geographically isolated homo erectus stocks throughout the
world. This, of course, is highly inconsistant with any notion of a common
ancestor -- Adam. This is one of the things that the "Eve" data clearly
points to -- that the multi-regional origin hypothesis is untenable.

Of course, even if we allow the 800,000 year old interpretation of the
genetic data, that is still a far cry from > 5.5 million years that your
view requires. Your 5.5 million years ago takes us all the way back to the
last common ancestor between chimps and humans. You are the only person
that I know that suggests that human beings originated that early.

TG

_____________________________________________________________
Terry M. Gray, Ph.D. Department of Chemistry and Biochemistry
Calvin College 3201 Burton SE Grand Rapids, MI 40546
Office: (616) 957-7187 FAX: (616) 957-6501
Email: grayt@calvin.edu http://www.calvin.edu/~grayt

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