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Darwin-L Message Log 7:89 (March 1994)

Academic Discussion on the History and Theory of the Historical Sciences

This is one message from the Archives of Darwin-L (1993–1997), a professional discussion group on the history and theory of the historical sciences.

Note: Additional publications on evolution and the historical sciences by the Darwin-L list owner are available on SSRN.


<7:89>From sarich@qal.Berkeley.EDU  Tue Mar 29 17:29:42 1994

Date: Tue, 29 Mar 1994 15:25:50 -0800
From: Prof Vince Sarich <sarich@qal.Berkeley.EDU>
To: darwin-l@ukanaix.cc.ukans.edu
Subject: Evolution within Homo

Some thoughts on the discussion inspired by the Time article on human
evolution:

I second the doubts expressed by Donnelly and Jacobs as to the claimed
antiquity of the Javanese fossils.  I suggest that one should think about such
reports as one would think about, for example, the recent claim of
30,000-year-old humans in Brazil -- asking the simple question of how they got
there without leaving any trail along the way.  The answer, of course, is that
they couldnUt have -- it is a long way from Alaska to Brazil -- and did not.
Ditto from Africa to Java.

I also second the comments of Princehouse with respect to the Chinese
so-called Homo sapiens skull.  There is a lateral view of it on pg 55 of the 3
March 1994 issue of Nature, which makes is clear that (1) this is nothing
resembling anatomically modern Homo sapiens, and (2) it looks as though it is
as old as claimed.  Morphological dating still works quite nicely, just as it
did for the 1470 skull in the early 70s; that is, 1470 did not look as though
it were 2.8my old, and, lo and behold, it was not.  She also points out quite
correctly that the Javanese date makes <ABSOLUTELY NO DIFFERENCE WHATSOEVER as
far as the African vs multiple origins debate goes.

On that debate, however, I have a fair amount to say.  From an old
introduction to an article now in press:

I argue here that all the available data on Homo sapiens (genetic,
morphological, linguistic, cultural) are most readily interpreted within the
framework of a phylogenetic tree that links extant human populations over a
time span of no more than 15,000 to 20,000 years.  This is not to suggest that
some ur-population speaking an ur-language lived in a geographically restricted
Garden of Eden 20,000 years ago, expanding out of there to lead to what we have
today.  Indeed, the scenario envisioned here goes to quite the other extreme in
seeing our 'Garden of Eden' as the entire inhabited world of that period.  I
suggest that as recently as 15,000 to 20,000 years ago the human population was
something approaching <panmictic> at all levels, and that most of the
interpopulational differences we observe today, and in the recent past, have
accumulated since then.  The proposed <panmixis> is seen as driven by glacial
pulsations which would have necessitated large-scale movements of populations,
not only in areas <directly> affected by the glaciers themselves, but also in
those that suffered the secondary effects of shifting climatic zones and major
sea level changes.  It thus must have been essentially world-wide, and only
after populations had begun to settle down in more-or-less their current areas
could regional differentiation leading to what we see today have begun.  Thus
we would have had episodic, glacial cycle driven, regional (racial)
differentiation subsequent to the expansion of Homo out of Africa, and
concomitant episodic obliteration (<panmixis>) of most or all of the
regionality.  We then simply appear to be living in one of those episodes of
regional differentiation, with ours beginning with the last glacial retreat.
These episodes of developing regionality would have been characterized by
differential retention of portions of the existing (which would have been ,
just as today, substantial -- but basically intrapopulational) plus significant
in situ developments.  The degrees of past regionality achieved would then,
presumably, have been strongly correlated with the lengths of the
glacial/interglacial cycles involved, and thus potentially much greater than
that present today.

That is the model; what follows is its genesis, development, and testing.
-----------------------------------------------------------------
Obviously this scenario renders the Garden of Eden/regional continuity
obsolete.  The article is entitled (admittedly immodestly) RACE AND LANGUAGE IN
PREHISTORY, and anyone who wants the current version can have it by e-mail or
hard copy for the asking.  It also explains (briefly) what is wrong with the
mitochondrial dates at both ends of the time scale at issue.

Vincent Sarich
Department of Anthropology
University of California at Berkeley

whoops! left out <argument> after <continuity> in the last paragraph.  Sorry
for the length.  I hope it will be worth it.

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