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Re: Shaking up the bird family tree
Found it. The paper is:
Whiting M. Bradler S. and Taylor M. 2003. Loss and recovery of wings
in stick insects. Nature 421: 264-267
Authors state that : "These results suggest that wing developmental
pathways are conserved in wingless phasmids, and that ‘re-evolution’
of wings has had an unrecognized role in insect diversification."
"These results support the hypothesis that the ancestral condition in
Phasmatodea is wingless, that the first six basal phasmid lineages are
entirely wingless, and that fully developed wings were derived later
in phasmid evolution, on as many as four occasions. Clearly, the
presence of wings is a very plastic feature in phasmids, with
congeneric species (for example, Lopaphus) exhibiting both partially
winged and wingless states. One of the correlates with winglessness in
insects is increased female fecundity2,3, and as phasmids scatter
specially modified eggs individually rather than concentrating them in
large numbers similar to their sister taxon, there may have been a
selective advantage early in phasmid evolution to shift to
winglessness to facilitate fecundity and increased crypsis."
So, essentially the punch-line is that phasmids (and likely other
insects, as well) can switch wings on and off rather easily. For
several reasons, I suspect the situation is less plastic in birds.
Still, an excellent point to raise (and a darn interesting paper,
On Jun 27, 2008, at 2:32 PM, Mike Habib wrote:
Didn't someone recently find that in a group of stick insects?
I'm afraid I don't have the reference at hand.
I think they may have - I know the paper you're talking about, and
I'll dig it out. That said, the thing about flight loss in phasmids
(and mantids, as well, to an extent) is that the non-flying taxa
seem to be grounded more by gigantism without wing enlargement, than
by true wing reduction (to an extent, anyway. The wings are truly
reduced in some taxa). The upshot is that flight loss/gain may be
unusually plastic in phasmids. Emphasis on maybe.
Michael Habib, M.S.
Center for Functional Anatomy and Evolution
Johns Hopkins School of Medicine
1830 E. Monument Street
Baltimore, MD 21205