>Tedd:
>> Actually, with feathers accounted for (warmth), the idea of
>> running creatures using the aerodynamic features of feathers
>> (strong but lightweight extensions) for leaping or short glides
>> seems to make any hopeful monster unnecessary.
Ami:
>And where are the feathers placed, and how is the limb they used to glide
>shaped? How did they happen to be aerodynamic? The only natural selection
>for flight is either escape from predators, or capture of prey. It would be
>far quicker to just develop speed. So either both animals are taking the
>same evolutionary path: flight which is more difficult, or one of them gets
>faster and the race is lost. You need a lot of chance happenings falling
>into place at just the right time. Remember, there is no purpose. The
>leaping animal does not intend its children to fly, nor does it imagine how
>it came to leap or how it can leap better or make better use of its
>insulating coat. Even if it can imagine how to leap better, it can do
>nothing about it.
the indidivuals who were better at leaping and then flying left behind more
of their offspring than the individuals who were lousy at it. That's how
natural selection works.
>(BTW, do we have fossils of primative feathers? That is just a curious
>question, not a point of argument)
yes we do
http://www.abcnews.go.com/sections/science/DailyNews/dinobird990225.html
http://odur.let.rug.nl/~nieuwlnd/source2.htm
>The only task natural selection takes into account is survival long enough
>to reproduce. Obviously single celled creatures do that very well. How did
>they gain new abilities?
they did it by clumping together and then some of the cells becoming
specialized. There's a nice accessible overview in "Sacred Depths of
Nature" by Ursula Goodenough
Susan
----------
For if there is a sin against life, it consists not so much in despairing
of life as in hoping for another and in eluding the implacable grandeur of
this one.
--Albert Camus
http://www.telepath.com/susanb/
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