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Re: Shaking up the bird family tree



On Thu, Jun 26, 2008 at 3:05 PM, Raptorial Talon
<raptorialtalon@gmail.com> wrote:
> "And that flighted tinamous evolved from flightless ostriches, says
> ornithologist Shannon J. Hackett of Chicago's Field Museum of Natural
> History, one of the lead authors, "can change the way people look at
> the evolution of flight.""
>
> Wow.
>
> Kind of like how flying bats evolved from flightless bears, right?

(Not quite the best analogy, but I'm having trouble thinking of a good one.)

> Right? Doesn't that just make so much sense?!

Yeah, given the many independent occurrences of flightlessness among
avialans, it seems more likely to me that, if their topology is
correct, flight was lost three times among palaeognathes: once in
stem-ostriches, once in stem-rheas, and once in the Apteryx-casuariid
stem group. Maybe more, depending on where the extinct flightless
clades go. (Who knows, though?)

> Maybe we should focus on trying to "change the way people write science 
> articles for laypeople" first.

No argument there.

Incidentally, I note that this topology poses a problem for Gauthier
and de Queiroz' (2001) definitions of _Ratitae_ and _Tinamidae_ (both
branch-modified node-based definitions). The former becomes restricted
to _Struthio camelus_ (or possibly smaller, if the species is more
inclusive than the crown group), and the latter now includes rheas,
kiwis, cassowaries, emus, moas, etc.! Seems like a good spot for an
unrestricted emendation or two.
-- 
T. Michael Keesey
Director of Technology
Exopolis, Inc.
2894 Rowena Avenue Ste. B
Los Angeles, California 90039
http://exopolis.com/
--
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