Re: An alternative to ST and AAT

Rohinton Collins (
19 Nov 1996 21:19:06 GMT

I'm going to enjoy this!

Paul Crowley <> wrote in article
> In article <01bbd4c4$ce230260$LocalHost@dan-pc>
> "Rohinton Collins" writes:
> > Paul Crowley <> wrote in article
> > >
> > > Chimp males demonstrate a high degree of competition, but show
> > > little dimorphism; this is probably because if they got much
> > > heavier they would not be able to sleep, or generally function,
> > > in the trees.

Probably? This is pure speculation based on the unfounded and unreasonable
assumption that 'if the males got much heavier ....'.

> > Sorry Paul, but this is absolute rubbish. Orang-utan males are twice
> > size of females, and lead an arboreal existence.
> You're not thinking. Orangs live in tropical rainforest in Borneo
> and Sumatra. They have NO predators (other than H.s.s.). Even if
> leopards were present they would find it hard to climb those trees.
> Orangs' nests can be large platforms. OTOH chimps live in general
> forests on mainland Africa and are constantly predated by leopards.
> Males need to be near females when they are in estrus and the trees
> in which they sleep would not support large nests.

You what? Chimpanzee retire to the trees and make a new bed every night.
Your above paragraph makes absolutely no sense whatsoever. One word Paul -
I have explained the widely held understanding of the reason why the
chimpanzee displays relatively little sexual dimorphism with respect to
body size (SDWRTBS), but it seems that you have seen fit to delete it from
this post and ignore it. Please re-read my last post. Failing that read any
contemporary text on primate social structures and how they affect SDWRTBS.

> > The reason for little
> > sexual dimorphism with respect to body size in the chimpanzee is
> > the social system is multi-male polygyny.
> This is an assumption. Evidence against it (proof?) would be a multi-
> male group with large dimorphism; i.e. baboons.

above is certainly no assumption, it is an inference based on neo-Darwinist
truisms, as well as observed fact.

> > > Large dimorphism certainly does not necessarily
> > > imply a single-male harem type of social structure, and the
> > > assumption that it does is far too facile. For example, highly
> > > dimorphic baboons do not have one.
> >
> > Incorrect again I'm afraid Paul. In fact a large degree in sexual
> > dimorphism with respect to body size correlates very highly with a
> > polygynous social structure. Baboons do actually have an dominant male
in a
> > group. The only way other males get to mate (without having confronted
> > dominant male) is by deception (mating out of sight of the dominant
> This is not correct. Chimps are nearly identical as regards such
> matings. All multi-male groups have a dominance system.

Look, if you lack knowledge on this subject, then go read a book or watch
some documentaries, but DON'T force us to endure your unfounded fantasies.

> I abominate the mindless application of general rules.

Science is all about looking for rules, for correlations, for order, so
that we may further understand .......

> They were not laid down by God.

Who asked you to bring god into this? I thought you were a scientist?

> They are derived from general observations
> and have no other validity.

No other validity? This statement denies your right to post to this
newsgroup Paul. Read the FAQ. Observations are what science is ALL about.
Only by observation may we learn more about the world, and universe, we
live in.

> At best their application to a
> particular case is an assumption.

An assumption is not based on observed fact.

> Why should multi-male
> promiscuous mating rule out dimorphism?

I refer you to my last post and my above ANGRY REPLY. And it does not rule
out SDWRTBS, it simply reduces it.

> Size counts in dominance
> conflicts and alpha's usually do most of the procreating.

You really do not get it do you Paul? Chimpanzees live in small groups
where the males are all related. This means that each male has an interest
in seeing that his brethren also have offspring. It is not in their
interests to compete against each other sexually to the EXCLUSION of all
others, which is what you are suggesting.

> Size counts in inter-group conflicts - invariably between males.
> There is no reason IMHO to conclude that A.afarensis had a
> polygamous system and numerous reasons for not doing so.

So you, alone amongst palaeoanthropologists, Paul, would ignore what we
have learnt by studying extant ape species?

> unit; it's males who are compelled by sexual competition to adopt
> less than optimum shapes or sizes (e.g. peacocks' tails).

Which is evidenced by a large degree of SDWRTBS in a uni-male polygynous
social structure.

Regards, but please READ my replies, and some relevant texts, as suggested.
Try the chapter on 'Bodies, behaviour, and social structure' in Lewin's
'Human Evolution'. This should be clear enough even for you to understand.