Re: origin of bats/reply 2 to TMK

[Mike Habib <habib@jhmi.edu>]

> 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.

Cheers,

--Mike


Michael Habib, M.S.
PhD. Candidate
Center for Functional Anatomy and Evolution
Johns Hopkins School of Medicine
1830 E. Monument Street
Baltimore, MD 21205
(443) 280-0181
habib@jhmi.edu