Re: Shaking up the bird family tree

[Mike Habib <habib@jhmi.edu>]

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."

And also:

"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,  
regardless).

Cheers,

--Mike


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.
PhD. Candidate
Center for Functional Anatomy and Evolution
Johns Hopkins School of Medicine
1830 E. Monument Street
Baltimore, MD 21205
(443) 280-0181
habib@jhmi.edu