Re: When did "Eve" live??

Keith (
Fri, 27 Dec 1996 22:02:38 GMT (Kevin Mackenzie) wrote:

>Hello everyone,

>A few years ago I remember hearing about a study (out of California I
>think) in which the researchers determined (with reasonable confidence)
>that all modern Homo sapiens have one common maternal ancestor. This was
>based on a genetic study. Does anyone know the authors or title of any
>publications on this study? Did the researchers estimate when this "Eve"
>lived and does anyone know of a similar genetic study performed for male

>Thanks in advance

The original study was performed by Cann, Stoneking and Wilson (1987)
in a paper entitled Mitochondrial DNA and Human Evolution, published
in Nature, Vol 325, pp 31 - 36. There are others thereafter which are
too numerous to list. It should be easy enough to find, but if you'er
REALLY nice to me, I may post you a copy (I accept bribes). It was
not definitive but basedon fairly good principles. Just be aware of a
few flaws.

The study was based on mitochondrial DNA (mtDNA). mtDNA is a remnant
of DNA left in the mitochondria from when these energy houses of the
cell were taken up as endosymbionts some ridiculous number of years
ago. Mitchondria are only passed on from mother to child, no paternal
mitochondria are inherited, therefore all mtDNA is of maternal origin.
The only way to do a similar study with an 'Adam' would be to use the
Y chromosome. Unfortunately this suffers from the problem of
recombination, which mtDNA does not, and it would therefore be
dificult to infer lineages from such data.

The authors estimated 'Eve' to have originated somewhere in Africa and
that she lived around 140 000 to 290 000 years ago. Unfortunately,
several of the assumptions made to reach these conclusions were
suspect. This is not to say that the work was all bad. I believed
they were/are on the right track, but should have been more careful
and perhaps taken longer to validate their data.

I hope this helps!!!

Keith Norris
University of the Witwatersrand
South Africa