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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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