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Re: Did Feathers Evolve for Dispaly? We Still Don't Know!



Michael Erickson <tehdinomahn@live.com> creates a straw man:

> I am addressing the claim that this discovery provides convincing evidence
> that feathers (in this post I will be including protofeathers under the 
> blanket
> term "feathers") initially evolved for display.

Maybe you should wait until someone makes that claim before you attack
it.  Even in your very own message the quote is:

"We therefore suggest that feathers first arose as agents for colour display"

How do you translate "we therefore suggest" to "this discovery
provides convincing evidence"?

I'm all for demanding evidence, but when someone suggests a hypothesis
you shouldn't go all Katie bar the door on them.

Next:

(1)
> For one thing, we don't actually know that _Sinosauropteryx_ itself
> used its feathers in display

and:

(2)
> Second, even if _Sinosauropteryx_ itself *did* use its vivid color patterns
> in display, that the animal had striking plumage in no way even begins to
> support the hypothesis that feathers themselves evolved for display, or at
> least not any more than that the bright and vivid plumage of many modern
> birds provides evidence for such.

but:

(3)
> Zebras possess extremely bold black-and-white striped fur coloration, so
> that predators examining the herd have a difficult time differentiating one
> potential target from another;

and:

(4)
> in the eyes of the color-blind mammalian predator, individuals and their
> outlines disappear in a sea of stripes

Seriously?  We know points 3 and 4 but we don't know point 1 and a
non-flying animal walking around with colorful feathers 125 million
years ago provides the same evidence as an animal living 10,000 years
ago when the issue is trying to understand form and function in
animals that lived 150 million years ago?  These are the positions
you're staking out?

> The point is that the hypothesis that feathers initially evolved as display
> devices is really no more robust today than it was yesterday, or the day
> before that, or the day before that.

So relevant data adds nothing to our understanding?  And do you really
want us to believe you're examining your own beliefs with this much
skepticism?  What can you tell us about the color vision of a lion?
To a lion, does the vegetation in the Serengeti have the same hue as
the stripes on a zebra?  What evidence can you provide to support the
idea that zebra stripes make individual zebras difficult for lions to
discern?  Or even that it makes any difference if it's true?  How
often does a lion try to chase a zebra surrounded by other zebras?

Then let's toss out that you haven't said anything about the visual
systems of the animals that lived around Sinosauropteryx or the
environment in which it lived.  You say "orange and white banded
coloration would serve purposes of camouflage just as well".  And you
know this how?  And your gripe is that Benton et al. are pushing their
hypothesis too strongly?

Wow.

--
Mickey Rowe     (MickeyPRowe@gmail.com