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Re: origin of bats/reply 2 to TMK
So the question is, if bats were climbing using all fours, why and
how would the change to using only the thumbs and folding the other
fingers under actually work? IMHO there has to be an intermediate
stage because if something is working right (climbing hands) they
don’t change without intervention.
This is an assertion, not really a robust conclusion. There is not
reason to think that climbing hands can't evolve dual function under
specific selective regimes. The fact that we can't imagine a
particular story to go with it is of limited importance in this
regard. Mechanically, climbing with only digit one, while folding the
other digits clearly works (as bats currently use this method). To
determine how a standard climbing hand gets to that point, we need
more fossil evidence and phylogenetic analysis. Just assuming that
there has to be a bipedal stage is not recommendable.
Michael Habib, M.S.
Center for Functional Anatomy and Evolution
Johns Hopkins School of Medicine
1830 E. Monument Street
Baltimore, MD 21205