First, my apologies to Mimi Koehl for misspelling her name, and to say
that this topic is a bit far afield from molecular evolution so I'll
keep this short.
I suggest that anyone truly interested in the issue of what
*morphospace* is physically possible for thermoregulation and
any enhancement of insect gliding abilities should read
Kingsolver, J. G., and M. A R. Koehl. 1985. Aerodynamics,
thermoregulation, and the evolution of insect wings: Differential
scaling and evolutionary change. Evolution 39:488-504.
Many of Ben Jones's questions may be answered there.
thomasb at spider.ento.csiro.au