Re: local evolutions

Bruce Scott TOK (
26 Aug 1996 13:07:56 GMT

On Thu, 22 Aug 1996 09:35:48 -0500, "C. Marc Wagner @ UCS"
<> wrote:

: I think that this theory has begun to fall out of favor in recent years
: as genetic evidence has come down on the side of the "Out of Africa"
: theory that several times in the past Hominids have migrated out of
: Africa. If I understand it correctly, the genetic evidence suggests
: that all living Homo sapiens sapiens are descended from a single female
: who lived around 800KYA. Much later than Homo erectus left Africa.

I haven't been following this story recently, but when and why did this
time scale become 800 kya and not 200 kya?

Yousuf Khan ( wrote:

: However, what evidence is there that it did originate in Africa?
: All we can guess at is how long ago it happened, but that doesn't
: tell us where it happened: it could've happened in Africa, but
: not necessarily so.

According to the original story, the evidence was that there is more
genetic diversity among humans in Africa than ahywhere else, consistent
with the hypothesis that diversity expands with time among non-migrating
populations. Also consistent with this is that the least diversity was
observed in native people from the Americas.

: What exactly do you mean? How do you measure genetic diversity?

I don't remember the details, but it had to do with certain alelle
frequencies in the mitochondrial DNA. It _was_ however quantitative.
Look it up in Nature articles from about 1992-1993.


Mach's gut!
Bruce Scott Congratulations to Ghada Shouaa,
Max-Planck-Institut fuer Plasmaphysik Olympic heptathlon champion!