Re: Evolution: A few questions

Glenn,

I refer to your response to one of Jason's recent questions. He had asked,

" What happens during the intermediary stages when a feature
 is evolving, but before it's fully functional? For example, I
imagine it took an EXTREMELY long time before the wings of an
 insect or animal (which evolved from whatever they evolved
 from) were perfected and enabled them to fly. What happens
 during "however many generations" the organism exists with
 wings that were not yet functional? Wouldn't this be more
 detrimental thus causing the evolutionary process to drop the
 wings before they're useful?"

A most reasonable question, we would all surely agree - and along the same
lines as the assumed 'fish > amphibian' transition that you and I briefly
debated in 2002 (detailed at the URL
http://www.calvin.edu/archive/asa/200204/0410). Here is what you had to say
to Jason:

"Feathers appear to have evolved as a body covering. That was useful to
 help keep the animals warm. But with some animals, the wings begain to
 help them escape predators. I can't find the reference now but there is
 a bird which uses wings to help it climb steep slopes but it isn't
 flight. In that way an animal with feathers can improve their ability
 to use air to propel themselves."

In my view, this hardly gets to the nub of things - indeed, it is as
disappointing as the answer you gave me. Precisely how does an incipient
wing confer selective advantage?

Vernon
www.otherbiblecode.com
Received on Wed Jun 16 20:15:04 2004