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



Michael Erickson <tehdinomahn@live.com> digs in:

> Nobody "attacked" anything.

You strongly attacked the idea that Benton et al.'s finding bears any
relationship to an explanation for the evolution of feathers as
display devices.

> Nothing in my post reads as an "attack", which I take to mean an aggressive 
> assault,

Perhaps you'd see my perspective better if you recognized that not
every statement is suffused with drama. Perhaps you'll be less likely
to do things like toss around accusations of unethical behavior if you
appreciate that people and points of view can be merely matter of
fact.  For instance, "Attack" does not necessarily equate to
"assault".

> and you completely missed the part where I mentioned how marvelous Benton et 
> al.'s
> new work on the life coloration

No, I didn't.  That you did that is irrelevant.  If somebody burns
down a house for the insurance money, I don't need to know or care
much less point out that they also rescued the family dog before they
tossed in the match.  Yes, this analogy is hyperbolic, but the logic
is directly applicable.

> They wouldn't be suggesting a hypothesis if they didn't think that there was
> convincing evidence for it, now would they?

As a matter of fact, they probably would.  Look back at things like
the discussion in our archives about ankylosaur tails being head
mimics.  People do suggest hypotheses that they don't feel are
strongly supported.  In fact, I'll toss one out right now... I
hypothesize that much of the way you relate to suggestions has to do
with the fact that you cut your teeth reading Bob Bakker's words...
Not everyone thinks in the same style as him.  People do say things
with less than 100% conviction.

> Oh dear. No one ever "Katie barred the door" on anybody.

It still seems to me your critique was grossly out of proportion to
your target especially since you hadn't even WFTP'd yet (that's
"waited for the paper" in case you haven't seen that here before).

> What does geologic time have to do with anything?   And haven't you ever heard
> of 'making an anology'?

Why yes, here's an analogy that occurred to me yesterday:

Do you think you'd learn as much about early airplane design by
studying a Joint Strike Fighter as you would by studying a Sopwith
Camel?

> Tsk, tsk. That was the crux of my post - that the colors of 
> _Sinosauropteryx_'s
> feathers is *not* terribly relevant to our understanding

Yes, and amazingly enough even when challenged you haven't seen the
weakness of your defense of that point.

> I'm afraid you've missed the whole entire point.

Perhaps, but you haven't convinced me with the current missive.

> 1) I am not examining Benton et al.'s beliefs with an unusual or unnecessary 
> amount
> of skepticism,

Do you leave room for disagreement?  As stated above, I still think
your message was out of proportion to the claim.  But I do admit I
might have been biased by the fact that yesterday's wasn't the first
message of yours I've read.

> 2) you (and those who you refer to as "us") can beleive whatever you (they) 
> want.

Thanks for that!

> That lions lack color vision (or at least well-developed color vision); anyone
> who wants to verify this claim can easily and painlessly do so.

Lions do not lack color vision.  Their color vision is not like ours.
However, you are doing yourself a disservice if you are assuming my
questions to you were naive.  Note that I followed up with a very
specific question:

>> To a lion, does the vegetation in the Serengeti have the same hue as
>> the stripes on a zebra?

You did not address that question.  Would you like to address it now?

>> What evidence can you provide to support the
>> idea that zebra stripes make individual zebras difficult for lions to
>> discern?
>
> Is this or is this not the most widely accepted hypothesis

What does "widely accepted" have to do with anything?  I asked you for
evidence, not the results of an imaginary poll.

> regarding the purpose of the zebra's stripes? Either A) it is, or B) I am
> horrendously misinformed.

Or C) A) and B) are irrelevant to anything of import because the
evidence supporting said hypothesis no better than the evidence Benton
et al. presented in support of the
feathers-evolved-as-display-structures hypothesis.  There are several
hypotheses about why zebras have stripes.  Some do have to do with the
vision of predators, but those hypotheses are more along the lines of
keeping zebras invisible from a distance.  There is no and I really
mean no hypothesis for the "purpose" of zebra stripes that's
particularly well-supported (by evidence; I don't know and don't care
how well supported any hypothesis is by opinions).

> Don't lions usually attempt to single out an individual from the rest of the 
> herd?

To sneak up on, yes.  But you're the one stating that we have all
these details so well nailed down that we can confidently say zebras
have stripes in order to make it difficult for lions to distinguish
individuals in a group, so why don't you tell me?

> And isn't singling out a individual necessary, as zebras are herd animals
> that rarely travel alone? Seriously.

"Alone" depends on the spatial scale you're talking about.  Spatial
scale is hugely important when you're talking about visual
capabilities.  With respect to the question of zebras being so densely
crowded together as to make it hard for lions to see individuals...  I
think you're imagination is running away with you.  Seriously.

> Let's see here.

Yes, let's.

> The fawns of many deer species are tan-orange with white markings, and this
> coloration camouflages the animal from predators whilst its parent is 
> searching for
> food and the like. Corn snakes are orange with red dorsal blotches edged in 
> white, and
> this coloration camouflages the snake against the tree bark and leaf litter 
> of its forest
> habitat. Red pandas are orange-red with prominent white bands on the tail (a 
> coloration
> very similar to that of _Sinosauropteryx_), and this coloration serves as 
> camouflage
> against the lichen-covered trees it inhabits.

And don't forget that flamingoes are pink so that they are camouflaged
against the sky away from the rising or setting sun.  And peacock tail
feathers are designed to be difficult to see when dappled sunlight
hits the forest floor against which they rest theiir tails...  Have
you ever heard of Abbott Thayer?  Are you trying to make me believe in
reincarnation?  Do you have even the slightest idea how many untested
assumptions underlie all of the claims you just made?  And that's
about LIVING animals.

> Hopefully that explains everything, and as with the claim that lions lack 
> color vision,
> anyone who wants to verify these claims about camouflage can easily do so.

Apparently I don't have your prodigious research skills.  Please
direct me to sources that make your claims stronger than Benton et
al.'s suggestions.

> No. My "gripe" is that the discovery that _Sinosauropteryx_ had 
> orange-and-white-
> colored feathers does not provide new evidence that feathers evolved for 
> display, and
> does not deem said hypothesis more robust than it was previously.

I'd actually agree that the links are weak.  I would NOT agree that
the evidence is irrelevant.  From what I've seen of the work, they're
trying to fill in a blank, not make an airtight case.  You could just
say it's an interesting idea and you'd like to see which way the
accumulation of evidence will point before you actually think it worth
your while to argue that it's unsupported.

--
Mickey Rowe     (MickeyPRowe@gmail.com)