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Yet More Nicholls vs Morgan
Phil Nicholls (pn8886@csc.albany.edu)
8 Jan 1995 17:35:55 GMT
Elaine@desco.demon.co.uk (Elaine Morgan) writes:
> Hi Phil (Chris?) This is fun, isn't it?
I would do it if it wasn't.
> You wrote: "You are not trying to reconstruct a phylo-
> geny."
You will pardon me, Elaine, but I have a great dislike to
being quoted out of context. While I don't think it is
necessary to quote an entire article I do think it is
necessary to provide enough so that those joining the debate
for the first time can follow the argument.
What I actually wrote was:
> > However, you are not trying to reconstruct a phylogeny or
> > establish a phylogenetic relationship. You are reconstructing
> > an ancestor, a protohominid, from characteristics that you
> > consider to be the result of an evolutionary convergence. Your
> > premise -- that hair reduction, sweating, fat distribution and
> > nose shape are aquatic convergences is also your evidence for
> > an aquatic phase in hominid evolution and is a classic example
> > of begging the question.
To which you have responded:
> No, I doubt we'd disagree on the phylogeny.
Don't be to sure. For example, I don't believe Lucy is a
direct hominid ancestor.
> I'm
> trying to address a simple question: Why is Homo unique
> among the primates in such a bewildering variety of
> ways? eg Functional nakedness, bipedality, prenatally
> acquired fat layer, descended larynx,disappearance of
> 90% of apocrines, proliferation of sebum, psychic tears
> accompanied by lump in the throat, moveable velum, eccrine
> thermoregulation, vernix caseosa. etc. The conventional
> response to most of which is : let's not talk about that.
In _Scars of Evolution_ you cite in the notes to chapter 4 an
article by Pete Wheeler which appears in the Journal of Human
Evolution, 1985 volume 14 (Your citation places it in volume 42,
which does not currently exist for the Journal of Human
Evolution. You also have the wrong page numbers). That volume
of the JHE is devoted to the issues of hairlessness and
sweating. Pete Wheeler has to date published about 10 articles
on the subject, including a recent exchange in the latest
issue of the Journal of Human Evolution.
I hope that by now you have seen my review of the issue of
eccrine /apocrine sweating. In this post I reviewed research
which shows very clearly that primates on the whole do not use
apocrine glands for thermoregulation, that in anthropoids the
apocrine glands become smaller and are reduced in number,
that chimpanzees do indeed give off eccrine sweat and that the
pattern of eccrine gland distribution in chimpanzees and the
rhesus monkey are identical to those in Homo.
Now I personally don't have time to investigate each and every
characteristic you claim makes us anomalous primates. I can
only point out that the two I have investigated (bipedalism
and eccrine sweating) are not anomalous at all. They in fact
confirm Darwin's thesis that human differences are of degree,
not kind.
> Second simple question: in what kind of habitat would these
> qualities be at a premium? If on the savannah, why are they
> not common among other savannah mammals instead of
> non-existent?
Now I might turn the question around and ask "If bipedalism is
such a boon to aquatic mammals why is in that none of them
have developed as bipeds?" However, that question would have
the same flaw as yours. The answer would be the same. The
question is meaningless because our ancestors were anthropoid
apes.
> To establish in what habitat they are at
> a premium, is it not reasonable to enquire what other
> creatures display these characteristics? In the majority
> of cases the answer is: aquatic ones. This is a striking
> fact.
Only if your broadly define aquatic to include any animal that
even looks cross-eyed at a body of water. Hardy's original
aquatic ape was truely aquatic. Yours is a wading ape. Why
does a wading ape lose body hair? I know of four primate
species that are comfortable in the water and NONE of these
have lost their body hair. What specifically was your wading
ape adapting to that required a loss of body hair?
Please tell me which aquatic mammals are bipeds.
Please tell me which aquatic mammals use eccrine glands for
thermoregulation?
> ST sems content to attribute it to the long arm of
> coincidence. I don't think the arm of coincidence can
> stretch so far,
There is no such thing as the "savanna theory." The savanna
figures in scenerios of human evolution because we KNOW that
two and a half million years ago early hominids were living on
the savanna. Bipedal locomotion is a TERRESTRIAL adaptation
and terrestrial primates tend to inhabit drier, open forests
grasslands. This is true of lemurs (Lemur catta is well
adapted to the drier regions of southern madagascar and spends
some 40-50% of its forging time on the ground) and Old World
Monkeys.
> > The vast majority of ALL fossils come from mud and silt.
> Yes, of course. I plainly stated that fossil evidence
> cannot prove the first hominids did not roam the arid
> savannah. My point was that it certainly cannot prove
> that they did (though that claim is often made or at
> least implied)
But I don't need to prove that the first hominids were
consumate savanna dwellers. As a matter of fact, I think that
the anatomical evidence suggests that A. afarensis was in fact
partially arboreal. The combination of partially arboreal and
terrestrial biped suggests to me that they were occupying a
niche that included the interface between forest and savanna.
But the fossil evidence DOES demonstrate that 2 million years
ago hominids were scavanging on the savanna.
>> We know that hominids eventually moved onto the savannah
>> and that makes it reasonable to conclude that many aspects
>> of hominid morphology are a result of adaptation to the
>> savannah
> Does it really make it reasonable? Even in respect of
> aspects shared by no other savannah animal?
Yes, because no other savanna animal is descended from an
anthropoid ape.
> The only species- specific human trait that we can date from
> fossil evidence is bipedality.
Actually there are many species-specific human traits we can
date from the fossil record. We can date the changes that
occur in brain size, the reduction in the size of the anterior
dentition, the reduction of the facial profile and the change in
shape of the dental arch, to name a few.
However, of all the traits you list as evidence for aquatic
ancestry the ONLY one present in early hominids is
bipedality. Unfortunately for you, bipedalism is not an
aquatic adaptation.
> As you say, many people now conclude that it predated the
> savannah. But you then posit, without offering any evidence
> for it, that all the other distinguishing characteristics
> evolved millions of years later, just because that would
> better fit your scenario. When I do a thing like that you call
> it begging the question. I submit that in this regard we are
> either equally innocent or equally guilty.
The difference between our two situations is that I am
proposing the following:
Arboreal Ape -------> Early Hominid ---------> Early Homo
(Common Ancestor) (Biped w/some (Bipedal, savanna
Arboreal) savanger)
8-5 mya 5 - 4.5 mya 2.4 mya
I have evidence to support all three of these steps that is
derived from fossils.
You, on the other hand, are proposing a detour for which you
have no fossil evidence.
By proposing that hair loss, sweating, etc. are adaptations to
the savanna I am merely drawing conclusions from what we know
about the first three million years of hominid evolution.
> > A theory or hypothesis is supported by evidence and not
> > by a lack of evidence for other competing hypotheses.
>
> I couldn't agree more. The weakness of ST is that as far
> as I can see it is not supported by any such evidence.
Except for the fact that we know that by 2.5 million years ago
hominids were living on the savanna as scavangers. Therefore
we know there was a transition from forest life to savanna
life. That is not a theory, that is a fact.
> You on the other hand say "having read Scars of Evolution
> I find no such evidence presented by you." I'm afraid this
> inability to see the force of one another's arguments
> is going to lay us both open to the attentions of the
> deconstructionists :-)
The force of your arguments is inversely proportional to the
expertise of the person reading your book. Pat and Troy tend
accept everything you say about anatomy and physiology. I do
not.
--
Philip "Chris" Nicholls Department of Anthropology
Institute for Hydrohominoid Studies SUNY Albany
University of Ediacara pn8886@cnsunix.albany.edu
"Semper Alouatta"
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