Re: GRACILITY IN TETRAPODS

[ornstn@inforamp.net (Ronald Orenstein)]

>I need some thoughts on a fairly simple issue, and thus start here with a
>relatively simple question. Does anybody know of, or can they think of, any
>mechanisms that might encourage the evolution of gracility in a lineage?
Besides
>the obvious speed-race theories. I am trying to find out if there is any
>evidence suggesting that molecular, ontogenetic or phylogenetic factors can
>create or exasperate such a change.

One thing to think about: what are the different selective factors leading
to gracility as opposed to simply smaller size?  If, for example, food
becomes limiting so there is an advantage to reducing body weight, eithr
gracility or dwarfism would do the trick - yet on islands, for example,
dwarfism seems the commoner result.  So whatever selects for gracility it
may not be a need to reduce body weight for purely energetic reasons (absent
adaptations for speed, etc.)
--
Ronald I. Orenstein                           Phone: (905) 820-7886 (home)
International Wildlife Coalition              Fax/Modem: (905) 569-0116 (home)
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