Re: Bipedalism and other factors and AAT

J. Moore (
Thu, 15 Jun 95 09:01:00 -0500

JM> >You are again incorrect when you state that chimpanzees are not under
JM> >pressure from non-human predators.

Tk> The fact is, chimpazees have very few natural (non-human) predators in
Tk> the wild and will live to a ripe old age in the wild.

Odd that you manage to suggest that, despite the fact that chimpanzees
manage to deal reasonably well with their potential predators, such as
lions and leopards, early hominids of similar size and brainpower would
be incapable of doing so.

JM> You gave a quote about how much water can be lost by active humans in
JM> the desert, which has nothing whatsoever to do with australopithecines
JM> unless they were in the desert. So your quote has nothing whatsoever
JM> to do with the subject at hand. (Question: How much water would, say, a
JM> wildebeest use in "an hour of walking in a hot day in the desert"?
JM> Answer: who cares? the desert has nothing to do with its actual
JM> habitat.)

Tk> The point was still that hominids do not conserve water very well, IN
Tk> ANY KIND OF HABITAT. I understand that they do not live in the desert
Tk> but I was merely pointing to their unusually high water consumption
Tk> rates. Did I not make that clear?

All that matters is whether or not they do *well enough*; that's how
evolution works. We see that in fact australopithecines did well enough
to survive in their environment for millions and millions of years. And
in fact even chimpanzees do well enough in relatively dry areas, similar
to those used by australopithecines.

Tk> If you really think I don't understand "how walking in the desert
Tk> differs from foraging and resting in a wooded savannah mosaic
Tk> environment" then I don't think you understood the point I was trying
Tk> to make at all.

Your point was, and is, irrelevant to the subject of australopithecine
adaption to their environment. Contrary to what you continually insist,
they just flat out worked in that environment; well enough to last there
for millions and millions of years.

Tk> > I don't think there is really any question, no matter what quote you
Tk> > come up with, that the susceptibility of early hominids to
Tk> > dehydration
Tk> > was probably pretty high. If you look at any other creature on the
Tk> > savanna, the ways in which they conserve water resources are far
Tk> > superior to the human/pre-human model. Their body temperatures are
Tk> > generally higher, they allow their internal body temperatures to
Tk> > rise in response to heat and they don't sweat, they pant.

Evolution works on what is there; it can't just build a whole new system
from scratch. Humans are primates, they evolved from primates, not from
antelopes, or pigs, or dogs. The fact that they use different physical
structures to accomplish similar ends compared to some other animals in
similar environments is not evidence that they didn't live there. In
fact, we know that they *did* live there, so whatever system they used
obviously worked well enough, regardless of whether or not other systems
worked "better". The "better" is in quotes because one problem with
using a physical adatation as a "solution to an environmental problem"
is that it almost inevitably reduces your options as a species. This
isn't a problem for a species that stays put in an environment that
changes slowly, but as it turns out for humans, it was yet another lucky
break in our evolutionary past that we didn't have such a gross
morphological adaptation to limit us.

JM> >And yet they *were* there; oh, not in the treeless and waterless
JM> >savannah that you imagine, but in the actual savannah environment that
JM> >existed in reality. And they were there for millions and millions of
JM> >years, which fact even the AAH accepts. So it is obvious that they
JM> >could and in fact did live and indeed thrive there.

Tk> Yes, they thrived in an environment that had the necessary aquatic
Tk> resources in order to replenish any fluids lost during the hot day.

Tk> I think you are still missing the point here. The AAH argument is that
Tk> if hominids
Tk> evolved EXCLUSIVELY in a savanna environment, then why don't they
Tk> conserve water
Tk> resources as well as other savanna creatures?

As I pointed out above, you can't just evolve whatever "takes your
fancy"; evolution works with what is there in the organism. So no, we
didn't survive there like antelopes do, or like warthogs, or by
burrowing and coming out at night, or by digging into the ground and
popping out every few months after the rains fall, or by any of the many
*different* ways that animals survived and still survive in that
environment -- we did it our way. (Everybody sing!)

Tk> Yes, but I never said anything about the sea shore. Personnally, I think
Tk> most
Tk> of the aquatic phases took place in fresh water rivers, lakes and
Tk> streams.

Tk> The estuarian crocodile lives in ESTUARIES which are BRACKISH; or
Tk> mixtures of some
Tk> salt with but mostly fresh water. If these crocodiles are exposed to
Tk> the kinds of
Tk> salt levels found in the ocean for a long enough period of time, they
Tk> will die.

As has been pointed out to you, both recently and several times
previously, you are incorrect.

Tk> Besides, crocodiles living in salt water, even though you seem to latch
Tk> on to this
Tk> issue rather quickly, is not the real issue for this news group.

I bring it up because a basic tenet of the AAH has been that "the
savannah" is full of dangerous predators, and the oceans (swamps,
streams, rivers, lakes, etc.) are not. The fact is that not only are
those waters full of dangerous predators, the predators there are also
demonstrably not as easy to see and do not respond to bluff and threats
as the major land-based predators [of large primates] demonstrably do.

Tk> I was not
Tk> implying that an aquatic environment was free from predators. I was
Tk> merely
Tk> pointing out that given our many physical deficiencies, which I am not
Tk> going to
Tk> list again, we must have evolved in a relatively safe environment. We
Tk> may have
Tk> developed defensive strategies to help avoid crocodiles. And I have
Tk> stated in this
Tk> news group before, that I would imagine it would be easier to deal with
Tk> crocodiles
Tk> as a predator than it would be to deal with lions, or big cats on the
Tk> open plains.

And here you make exactly that bogus point, contrary to fact.

Tk> The first reason is because crocodiles lay their eggs in shallow nests
Tk> around the
Tk> edges of their aquatic environment and do very little to defend these
Tk> nests.
Tk> These eggs would make a very good meal for early hominids and it would
Tk> be an
Tk> effective way to control the population of crocodiles as a whole.

The fact that crocodiles thrived in massive numbers along every African
waterway until extremely recently convincingly demonstrates that their
population wasn't well enough controlled to keep them from being a
constant danger to anything of reasonable size which enters the water
(fresh or salt).

Tk> I doubt if early hominids would have any chance of making a meal
Tk> out of lion cubs or leopard kittens.

Judging from the chimp actions at the leopard den at Mahale, I don't
think they would make a meal of them either. The chimps didn't eat the
leopard cub, they just killed it.

Tk> Secondly, crocodiles are dumb. They are much dumber than
Tk> lions, and I
Tk> would imagine that a defensive strategy could be developed to deal with
Tk> them after some examination of their habits.

Sure: stay out of the water. Quite effective, and easy to figure out

It's their stupidity that makes them so hard to deal with. They just
don't respond well to threats, as the relatively smart mammalian
predators do.

Tk> >Tk> Haven't you ever been to the beach?
Tk> >Tk> Troy Kelley

JM> >Yes, I have, but didn't swim or wade, due to the prevalence of shark
JM> >attacks in the area.

Tk> Shark attacks kill fewer people than lightning does each year. You
Tk> should have
Tk> gone in the water. BTW, did you drive to the beach? That is much more
Tk> dangerous that swimming in the ocean as well.
Tk> Troy Kelley

Perhaps if *you're* driving. When driving, as with land-based mammalian
predators, you have some control over the situation (well, *I* do, anyway).
If you keep your wits about you, you can usually see trouble coming and
therefore take effective steps to avoid it. With sharks as with
crocodiles, your chances of seeing the trouble coming are greatly
reduced, and your chances of doing something about it once it arrives
are virtually nil.

Jim Moore (

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