Re: puzzle of the negrito: isolated archaic populations
Gerold Firl (geroldf@sdd.hp.com)
19 Dec 1996 21:00:51 GMT
In article <E2IHEr.Lp@liverpool.ac.uk>, dbarnes@liv.ac.uk (Dan Barnes) writes:
|> In article <58s45k$con@gazette.bcm.tmc.edu>, pdeitik@bcm.tmc.edu says...
|> >So unlike
|> >what has been discovered in europe, which can be summerized as
|> >evidence for interspecies cultural exchange (with a lack of any
|> >genetic exchange) in southeast asia there is simply no evidence for
|> >temporal territorial overlap. In addition there is no reason, based on
|> >genetic studies, to suggest that these ancient southeast asians are
|> >not out of africa.
|> Of course the new dates for H.e. (27 to 53 ka) in Java throws a different light on
|> this. There may have been a degree of temporal overlap. I have also heard
|> suggestions, although I have no ref for them, that H.e. had colonised at least one
|> island (c. 700 ka) that would have needed boats - even at low sea levels.
Not to keep harping on this, but I think there is an under-appreciation
of the effect of the glacial pump on population movements. Go to william
calvin's web site (http://weber.u.washington.edu/wcalvin/index.html) and
browse through some of his texts; I believe it's _the ascent of mind_
which discusses the effect of ice-age climatic change on geography and
population movements in a very lucid manner.
As the glaciers advance and retreat, ecological zones move hundreds of
miles north and south. Plants, animals, including hominids: all track
the movement of their resident eco-zone. Not only is there a north-south
translation, but other significant effects creat population movements
and concentrations: exposure and inundation of continental shelves being
one of the most important.
The fundamental period of the ice ages is 100,000 years, with smaller
fluctuations occuring within the larger cycle. Thus in SE asia, where
genus homo has been found for about a million years, roughly ten major
cycles of population advance/retreat has taken place. This is one of the
main reasons for the lack of regional speciation seen in man: large-scale
mixing caused by glacially-induced population movements. Austronesia is
precisely the place to see the ragged edge of such mixing, since it is
at the end of the line for migration, and inter-glacial inundation
isolates small populations for huge stretches of time. Pre-modern
colonization of australia, before the invention of blue-water
technology, created a huge reservoir of archaic h. sapiens who were
present when truely modern man arrived, roughly 40,000 BP. Hybridization
did take place there.
The apparent lack of hybridization between neandertals and h. s. sapiens
indicates that neandertal *should* be classified as a separate species.
In austronesia, on the other hand, it appears that genetic diffusion
rates were sufficient to prevent speciation from taking place.
|> However, you are right in concluding a lack of evidence for genetic continuity.
Alan Thorne of the australian national university in canberra, writing
in the _cambridge encyclopedia of archaeology_, concludes that there
*is* evidence of genetic continuity between australian aborigines and
pre-h. sapiens populations in java. To me, such a conclusion appears
quite unmistakable; the archaic features of certain modern day
australians is obvious. Couple that with a fossil record which shows
both fully modern skulls and contemporaneous archaic skulls, which fall
outside the current range of variation in australia, and the conclusion
of multi-regional contribution to current populations is clear.
--
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=-=-=-=-=-=-=-=-=-=-=-=-=-=---- Gerold Firl @ ..hplabs!hp-sdd!geroldf
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