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Re: Campbell's even crazier than a MANIAC? (archeopteryx
--- On Wed, 9/24/08, Mike Habib <email@example.com> wrote:
> So, essentially, we might predict that a greater percentage
> of powered
> flyers would come from arboreal lineages than terrestrial
> ones. In
> practice, this doesn't seem to have worked out - birds
> seem to have a
> mostly terrestrial ancestry (with some semi-arboreal
> members possibly
> present), and bats seem to have an arboreal ancestry, while
> and insects are somewhat equivocal at present.
No telling how many times insects evolved flight, nor in how many ways not
available to verts, so I will unilaterally exclude them :D.
Given the presence of easy-to-climb trees (e.g., cycads), and good reasons to
climb them daily, but perhaps not spend all day there, I do not see where the
terrestrial ancestry of birds necessarily speaks to a ground-up scenario.
Given an Earth-type planet populated w/ a generic terrestrial vertebrate
species, and a large block of time, my wager will be that the majority of the
eventual fliers (and the first) will have taken a gravity-driven route, because
it is "easier".
This is a much different proposition than betting the farm that the crow
outside my window "probably" arrived here by jumping out of a tree. I have not
done that, as I believe you know...