Yoyoism (was Re: Endothermic Crocs in Nature)

[Dino Guy Ralph <ralph.miller@alumni.usc.edu>]

"Tim Williams" <twilliams_alpha@hotmail.com> writes:
For example, I know of no "neoflightless" insects, nor
"neoamphibious" proto-cetaceans.

Many phasmids (stick insects) appear to be neoflightless, and secondary 
flightedness has apparently evolved independently in four distinct phasmid 
groups since this initial neoflightless event.  In fact, a couple of phasmid 
clades apparently lost their wings, regained their wings, and lost their 
wings yet again.  But don't take my word for it -- read the paper for 
yourself at 
http://www.eeb.uconn.edu/Courses/Eeb477/Whiting_etal_phasmid_04.pdf#search='convergent%20evolution%20%20Phasmid'. 
Figure 3 is particularly fun.

I hereby coin the term "yoyoism" to describe this aspect of numerous 
reversals of a particular character within a lineage.

--------
"Dino Guy" Ralph W. Miller III
Docent at the California Academy of Sciences
proud member of the Society of Vertebrate Paleontology