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Re: OUR FRIEND, THE KIWI



>         Incidentally, if anyone hasn't heard, the Kiwi egg is
> _not_ a leftover adaptation from Moas as Gould has stated, kiwis
> aren't even all that closely related to them. I think this is one
> reason why Gould pisses some people off: "Oh, the Kiwi egg has no
> adaptive significance, it's just a random accident of evolution". If you
> have the view that who lives and who dies is more or less random, and that
> a lot of adaptations are just random, then if you run into a puzzle, it
> gives you an easy way out: "Oh, you're just trying to use the failed
> paradigm that all adaptation must be functional".

     If it wasn't for left over adaptations, there wouldn't be any
cladistics, or any phylogenetic reconstruction at all for that matter, of
extinct organisms.  These relationships are inferred using homologies,
which are "left-over" anatomical features shared with closely related
organisms that may or may not still have adaptive value.
     Additionally, the term "random" , when applied to evolution, is a
little misleading.  What is meant by that is that the environemtnal and
ecological changes that cause evolutionary change in an organism are
unpredictible, so the sorts of adaptations that an organism may be called
upon to develop in order to survive (and the potential niches that open
up for exploitation; do you think the mammals knew beforehand that the
large terrestrial animal positions werre going to open up at the end of
the Cretaceous?) are unpredictible.  It DOESN'T mean that the fact that a
polar bear has thick layers of fur and fat, and the fact that it lives in
a really cold environemnt, are totally coincidental.

LN Jeff
O-