Re: An alternative to ST and AAT
Thomas Clarke (clarke@acme.ucf.edu)
5 Nov 1996 15:21:39 GMT
In article <01bbcaf8$3113c520$962270c2@default> "John Waters" <jdwaters@dircon.co.uk> writes:
>Thomas Clarke <clarke@acme.ist.ucf.edu> wrote in article
><55lpgn$qs0@news.cc.ucf.edu>...
>> Don't you see a difference in these cases.
>> H.s and preceeding hominids and australopithecenes are
>the only
>> animals ever to "walk like a man". [at least I know of
>no others]
>> (snip)
>> Does this not suggest the possibility of special
>evolutionary
>> circumstances? If the circumstances were not special
>then why
>> are there not lots of animals that walk like a man?
>JW: There are only three species of knucklewalking
>primates. And
>only one species of fistwalking primate. Does this imply
>special
>evolutionary circumstances? Or simply that a small number
>of
>species used these adaptations?
Well, perhaps we are just saying the same thing in different
ways.
The fact that a small number of species uses an adaptation
to me implies that something special is going on. If the
adaptation is adaptive as it must be, then one would expect
over time that the adaptation would be "discovered" by more
than one or a few species.
Of course, A's and H's have been only around for a few million
years which is an evolutionary eye blink, so maybe all that
is going on is some sort of anthropic selection. E.G. true
bipedalism, walking like a man, may be prerequisite for development
of intelligence and science. Hence asking the question of
why did bipedalism, man-style, arise is sort of a self fulfilling
prophecy. It may be the case that only a biped can ask that question.
On the other hand, why did human-style bipedalism and concomitant
intelligence arise at this point in geological history?
Climate? (e.g. ice ages, dry climate. what?)
One would hope that some explanatory factors can be identified.
However, it could just be that bipedalism is one very unlikely
mode of locomation that arose by chance a few million years ago.
Tom Clarke
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