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Re: Waking up covered in dew
Paul Crowley (Paul@crowleyp.demon.co.uk)
Wed, 21 Aug 96 10:36:06 GMT
In article <3217C4A1.41E3@worldnet.att.net>
comsec3@worldnet.att.net "Gotschall" writes:
> > The surprising thing to me is that the author apparently accepts
> > that a recent and substantial part of our evolutionary history
> > was, in fact, spent in such a habitat.
>
> Thanks again everyone for the input, it has been enlightening. I should
> know better by now but I am surprised that cold appears to be a critical
> factor in this problem. Paul, your last statement kind of threw me
> though. I took it to mean that you disagreed with the savanna idea. If
> so I would be interested in hearing your views.
I think that Elaine (following Alasdair Hardy) has, in rough
outline, the right idea about the conditions for the initial
speciation. However, they both accepted the traditional idea
of a savannah existence for the last 3-4 Myr. But, to me, every
aspect of our anatomy screams out a denial of this: our soft
hairless skin, our slow terrestrial speed, our copious sweating
of water and salt, our poor sense of smell and our enormously
fat babies. It is, frankly, absurd to suggest that such an
animal could survive for a few days, let alone a few nights, let
alone raise a family, let alone have evolved, on the savannah -
prior to fire, good shelter, advanced weapons and, probably,
domesticated cattle.
I believe that at about 5 mya the hominid line adapted into a
completely new niche, for which bipedalism was necessary; and
in which it *stayed* until about 10 kya. This was the littoral,
with shellfish forming a significant part of its diet. The crab-
eating macaque indicates the possibility of such a niche. As a
result of the recent rise in sea levels virtually all of the
fossil record is now 100-200 metres below the surface. However,
wherever there are geologically upraised coasts in the tropical
or semi-tropical old-world dating from 150mya to 10 kya, vast
shellfish middens are found.
The change in dentition shown by A.anamensis and A.afarensis
indicates an departure from the forest diet and an adaptation
of a chimpanzee type of mouth to the crushing of shells. Thick
enamel was needed to protect against damage caused by small
pieces of shell.
The surplus population in each generation would be forced to
move inland, and would tend to stick to the inland lakes, where
a highly disproportionate number would be fossilized. They
would have to adopt a rougher diet and would generally die young
with worn teeth, as the record shows.
Until the use of fire, nocturnal predation would have inhibited
the permanent colonisation of inland areas or of oceanic coast-
lines. Early hominids had to stay by an inland sea where they
found nocturnal refuge on sand banks or shelves of rock or dead
coral. This meant that core populations were small and localized,
thus enabling rapid evolution.
This theory provides answers to many of the problems that regular
PA prefers to avoid. In addition to those provided by the AAT
for the niche, the reasons for speciation, for bipedalism and for
other aspects of the human anatomy, it accounts for the changes
in dentition, the extraordinary pattern of the fossil record
(e.g. that only four AMH skulls have been found) the age distrib-
ution of the fossils and their excessive tooth-wear, the problem
of nocturnal predation, the rapid evolution of the species, and
the number of human (especially water-borne) parasites.
It provides a meaningful focus for the development of advanced
societies with sophisticated language ability and extensive
agriculture, over the last 200 Kyr or so, which have no sense,
function or possibility, in the small, scattered, nomadic hominid
bands traditionally envisaged.
Paul.
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