David M woodcock (
27 Jun 1994 03:01:25 GMT

This reproductive isolation requirement for speciation
greatly influenced my thinking when I was reading on
this subject 12 years ago. It appeared that neandertal
man was a West Eurasian/African phenommenon. He
seemed one way erectus could develop --toward a better
open country hunter : smarter, more cold adapted, perhaps
However H.s.sapiens seemed to be reversing the trend toward a
more effective open country hunter -- he was less well muscled
than erectus, certainly dramatically less so than neandertal.
H.s.sapiens seemed adapted for a different biome -- one with less
food for [Acheulian technology] humans, perhaps temperate
forest. [This parallels the argument that preagricultural
rain forest populations, e.g. in central Africa,Queensland,
are small because the human food there is less than in
grasslands and what there is is mostly in the canopy]

I wasn't very satisfied with this as biome differences didn't
seem enough to account for the divergence observed; [short of
speciation to be sure ; I felt Shanidar was good evidence of
interbreeding] for a wide-ranging creature like erectus.

I had written off E.Asia as a backwater because of the
absence of Acheulian tools til c. 100 000 BP. Now with the
bamboo hypothesis, the skull series from E.Asia, and
the apparent presence of H.s.sapiens in the East Med about
100 000 BP for the first time I think the H.s.n/H.s.s.
divergence can be attributed to a genetic bottleneck
between W.Eurasia/Africa and E.Asia -- lasting perhaps
400 000 years. My guess is about 100 000 BP H.s.s.
groups -- having mastered the difficult problem of
living in tropical forest started to spread thru SE Asia
to the West. With the advantage of larger groups
[as each member required less food than each neandertal]
and a culture more suited to a variety of biomes they
dominated the temperate & tropical West within a few 1000 years.

However their stone artifacts were no better than the
neandertal's [which they no doubt copied]. This I
think is indicative that at 100 000 BP they weren't
yet competitive physically or culturally in the tundra
steppe biomes of Europe. The last interglacial
[c 40 000 BP] replaced European steppe with forest and
gave them the edge. They entered with a technology that
had advanced in 60 000 years and remained more than
competitive when the ice returned.

So the out-of-Africa theory of sapiens sapiens origins is
wrong. The multi-regionalist theory is better: there's no
reason to suppose H.s.s. and H.s.n. couldnt interbreed
indeed there's evidence to the contrary. But the
picture isn't quite as smooth as the theory suggests.
In particular I doubt anyone will find skull series
starting with erectus and ending with sapiens sapiens
in Africa comparable to the E.Asian ones.