Re: Niche, not "bipedal n

J. Moore (
Thu, 5 Oct 95 15:55:00 -0500

Mu> (J. Moore) wrote:
Mu> > It just happens that
Mu> >a predominately bipedal primate would do well in such an available
Mu> ^^^^^^^^^^^^^^^^^^^^^^^ &&&&&&
Mu> >niche, for a number of reasons, such as a primate's (and especially
Mu> >an ape's) relatively high intelligence, their heavy reliance on
Mu> >eyesight, and their carrying abilities.

Mu> Did bipedalism develop before hominids were in the "mosaic savanna ?"

It could have. It just happens that such an adaptation is
particularly useful for a variety of reasons in open countryside.

Mu> >These last two are also
Mu> >enhanced, in open country, by bipedalism. Bipedalism allows one
Mu> >to see over more grass and brush even while moving, and allows
Mu> >carrying objects, such as food or tools, further with greater ease
Mu> >(i.e., while remaining in a naturally comfortable position).

Mu> So the early signs of bipedalism were enhanced in the savanna ?

Rereading my sentence, I'd have to say I didn't word that well.
What I was attempting to say there was that the early hominids'
abilities, which I mentioned, are even more useful in relatively
open country than in dense forest.

Mu> Could someone explain how the "mosaic" in the "mosaic savanna" explains
Mu> in bipedalism that simple savanna doesn't. Perhaps grassland instead of
Mu> savanna might be more appropriate.

"Grassland" is just one type of savannah; much savannah contains
trees, sometimes quite a few, and most all savannah is interpersed
with rivers, waterholes, forest and brush of varying types and
densities (that's the reason for saying "mosaic" in describing the
enviroment). So "grassland" instead of "savannah" would simply be

Mu> In trying to visualize this, did the
Mu> hominids already live in the dense forest (with early signs of
Mu> bipedalism) and then as the dense forest changed into savanna, early
Mu> bipedalism helped in predation/escape and ultimately evolved to its
Mu> present stage (?).

Except for your focus on "predation/escape", that's more or less
the view today, with varying emphasis amnong different researchers
on how critical the open country was at the very beginning stages
of the transition from common ancestor to hominid. Predation and
dealing with predators were likely not particular problems for
very early hominids, just as they aren't for chimps, especially in
relatively open environments (except now chimps have us as
predators). Although it certainly is the case that habitual
bipedalism being used most of the time would be a great help in
predator avoidance, more likely as spurs would be the day to day
activities of food-getting.

Mu> Hmm, perhaps when looked at the evolving system as a
Mu> whole, less energy went into the system (at least all man had to do was
Mu> simply stay where he was :) to create bipedalism than migrating to the
Mu> sea/coast. Thermodynamist, does that make sense ? :-).

Well, it should be noted that Morgan doesn't propose a "migration
to the sea-coast"; rather she proposes that an arm of the Red Sea
cut off a population of pre-hominids, and that this population
became adept swimmers and divers but still, Gilligan-like,
couldn't get off their island by crossing a not-too-large strait.

She doesn't explain how these highly effective swimmers and divers
stayed trapped on an island for several million years, but then
that's only one of many things she doesn't explain. For instance,
she doesn't explain why they didn't evolve kidney modifications,
as other marine mammals all have, to deal with the otherwise
lethal doses of salt in their environment, nor why the human
lacrimal (tears) system, in terms of excretion, has more in
common with the "salt" glands of land reptiles and birds rather
than marine reptiles and birds as she claims.

Jim Moore (

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