[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
RE: Feathers from gills/lungs and morphogenesis of feathers
>>If the same genes are responsible for the
growth of lungs, and lungs are evolutionary descendants of gills,<<
They aren't. Lungs and gills (in vertebrates, that is), are two
completely different structures. Lungs evolved in some early group of
boney fish to get oxygen out the air when murky, stagnant water was
useless for gills. Many species did (and some still do) have both gills
and lungs. Land-living vertebrates lost their gills, while some types
of boney fish modified their lungs into swim bladders to help them
control their buoyancy in water.
>> then is it
possible that the feather shape (not function) is a carry over from
gills of some early amphibious animals.<<
Well, something similar may have happened with insects (dragonfly larvae
actually have two sets of paired gills very much like wings), but not
with birds. Feathers are made of keratin, gills out of---I suppose that
depends on the animal. Some of them are just looped blood-vessels,
right? So there really isn't much correlation between gills and
feathers, neither structurally nor developmentally.
I could see how that _could_ happen, though. Good science fiction idea.