Re: AAT Questions...
J. Moore (email@example.com)
Sat, 12 Aug 95 17:31:00 -0500
El> Subject: Re: AAT Questions...
El> Date: Tue, 01 Aug 1995 15:50:42 GMT
El> Convergent evolution is a respectable scientific concept.
El> People have registered irritation with the way I use the word. Maybe
El> because (a) I use it to account for single enigmatic features rather
El> than overall morphology, and (b) I suggest there may be signs of
El> convergent evolution having specialised an animal for a niche which it
El> no longer occupies.
No, the irritation is due to the ad hoc way you attempt to use the
concept: you use the concept only when you think it fits your theory,
and studiously ignore all instances when it does not. For instance,
there are several questions that have been floating around this
newsgroup about why humans are "odd man out" in several features
compared to marine mammals. These are in regard to features that
have evolved time and time again, due to convergent evolution, in
aquatic and marine mammals.
These features include: shorter legs, smaller or non-existent
ears, young born in an advanced state and/or very quick maturing
young, and very large, heavily lobulated kidneys to excrete excess
salt. Compared to marine mammals, humans are "odd man out" in all
Your theory ignores these features and makes no attempt
to explain why these ubiquitous aquatic marine mammalian features
were somehow exempt from the power of convergent evolution in one
singular case -- humans.
These are features that have to be explained: if humans, as you
claim, developed many of their distinguishing features due to
a process of convergent evolution with marine animals, why did
they not also develop these other features, which are common or
universal amongst marine mammals?
Yet you say that all theories which postulate a land-based
transition from the common ancestor must be incorrect because
you claim that humans are "odd man out" amongst terrestrial
mammals because, as one example, they don't cool themselves like
"the wild ass and the camel". But you make no attempt to explain
the "odd man out" status of humans compared to marine mammals.
Why does the AAT get this special pleading, this special exemption
from explaining the data, this special status where only the data
you find useful need be discussed: Why is the AAT, alone amongst
theories of hominid divergence, supposed to be accorded this
Jim Moore (firstname.lastname@example.org)
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