Time to update taxonomy?
cfstumpf at UNITY.NCSU.EDU
Fri Jan 31 14:08:06 CST 2003
That's right, Lynn.
The authors claim that
a) the ancestral condition in Phasmatodea is wingless
b) that first six basal lineages are wingless and wings were derived later
c) that wings were derived four times
I cite directly here: "..... wings did not re-evolve de novo in phasmids,
but are rather re-expression of the basic insects wing which was lost in
ancestral stick insects".
Their explanation for the wing formation genetic pathway not get loaded with
mutations is that is has been recruited from the limb formation pathway and
cannot be easily changed without major changes to other important genetic
pathways. Wing formation can apparently be switched on and off as seen in
the phasmid tree, but that probably extends also to other insect taxa. The
authors speculat that this phenomenon may be a more general trend in nature.
The article is very interesting to read. I can only highly recommend it.
(Nature 421, 264-267, 2003).
NC State University
>I am puzzled. Is this illustration, "the big wing switch"on the link below,
>from the Nature article mentioned?
>If so, can anyone explain to me just where wings were lost and regained.
>I see four separate origins of wings and two subsequent losses but no
>regaining of wings after they were lost. I haven't read the article but was
>shown the cladogram (in an article in New Scientist) by a colleague who
>asked this same question.
>Some simple explanation would be appreciated. After all these prestigious
>journals can hardly be wrong, can they?
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