Re: Origin of feathers

[Dinogeorge <Dinogeorge@aol.com>]

In a message dated 98-04-10 08:21:39 EDT, jjackson@interalpha.co.uk writes:

<< The benefit would be immediate in my skin-friction drag senario, surely? >>

Yes(!). If the pre-feathers first appear as "peach fuzz" all over the animal's
body, or at least, in areas well exposed to the air at the leading edges
(particularly the forelimbs), they will surely increase aerial friction and
allow a small, wingless, arboreal animal to better interact with the air when
it is in free fall. If the animal has an arboreal lifestyle, this would fill a
prior "need" and would therefore be selected for. The smaller the animal, the
stronger the air-friction effect.

Now if the pre-feathers >also< served as a sulfur-excretion mechanism, they
would have filled >two< needs simultaneously. One problem with pre-feathers as
sulfur-excretion mechanism is that the animals don't have to be arboreal to
"need" the feathers (so to speak). So by filling two needs, pre-feathers would
be >strongly< selected for in arboreal animals. Throw display into the mix as
something that additionally compels the persistence of pre-feathers once they
appear as "peach fuzz," and the only thing left is the wait for the pre-
feathers' initial appearance. We don't require that the animals be homeotherms
or anything like that, in the beginning. They could simply have been fuzzy
little archosaurs.

Luis Rey painted one of these for the frontispiece of my 1994 Omni article. I
originally wanted twelve stages in the picture, but had to settle for six due
to time and space considerations, so the fuzzy archosaur is also up on semi-
erect limbs (something like a tree-climbing chameleon).