Re: Origin of feathers

[Thom Quinn <swo@execpc.com>]

George, come on, I understand your arguments and I highly respect your
ideas, but don't make mine into a straw man! I'm not talking about
nonogenesis or orthogenesis and I think you are well aware of that!

Dinogeorge:
> Heavens! I'll certainly agree that there could have been display >behavior  
> before the evolution of pre-feathers. But pre-feathers, being >absent, could  
> not have been part of it, and I see no way in which the >organism could 
> "wish"  those pre-feathers into existence.

Thom:
Hey, no one is suggesting that organisms are "wishing" these into
existence. This is not a neo-larmarkian explanation. Pre-feathers
obviously came about from some kind of mutation to the dermal surface,
either via scales, skin, or a new kind of structure. This example is
totally hypothetical: The red skinned dino does well at attracting
mates. A mutation occurs. The red skinned dino with the sudden new
ridges does much better, at least with some mates that like the novel
"show" of ridges added. 

Dinogeorge:
>Once the pre-feathers appear, of course, they can quickly be exapted >into the 
>display rituals. (Not to mention that the  "behaviors evolve >first" 
>hypothesis is ridiculously untestable!)

Thom:
That is what the display and informational origin hypotheses suggest:
that the initial protofeathers became part of the displays. Obviously,
before they exist, there can be no direct selection on them!!! 

The "behavior evolve first" hypothesis is one of the main tenets of
modern zoology. And it is not always untestable! In this case, yes, I
agree, it is hard to test.