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

[David Marjanovic <david.marjanovic@gmx.at>]

Michael Erickson wrote yesterday...

>  Nobody "attacked" anything. Nothing in my post reads as an "attack"

I have noticed you are generally very emotional about science. It has 
already got better -- your first appearances on Tet Zoo were pretty hard 
to stomach --, but still you get way too much involved personally.

> > How do you translate "we therefore suggest" to "this discovery
> > provides convincing evidence"?
>
>  They wouldn't be suggesting a hypothesis if they didn't think that
>  there was convincing evidence for it, now would they?

They absolutely would _suggest_ one (they even used that exact word). 
It's normal to throw out several suggestions that are compatible with 
the evidence as an incentive for people to think more about this topic 
and do more research about it. You haven't read much primary literature 
yet, have you? :-)

> > So relevant data adds nothing to our understanding?
>
>  Tsk, tsk. That was the crux of my post - that the colors of
>  _Sinosauropteryx_'s feathers is *not* terribly relevant to our
>  understanding of why feathers evolved in the first place; we always
>  knew that the feathers of _Sinosauropteryx_ were most probably *some*
>  sort of color (even it was white), so the discovery of the exact
>  nature of said colors says little if anything about the origin of
>  feathers.

Finding out what kind of color pattern the feathers of one of those 
feathered dinosaurs that are least closely related to birds had -- 
that's certainly relevant if we can find something out about the 
function of that pattern.

However, the Early Cretaceous *Sinosauropteryx* is less relevant than a 
Middle Jurassic compsognathid or tyrannosauroid would be.

> > What can you tell us about the color vision of a lion?
>
>  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.

I don't think any research on the color vision of specificially lions 
has ever been done. Mickey R. will correct me if necessary. Judging from 
those placentals whose color vision has been investigated, lions are 
most likely red-green blind, but not entirely colorblind; so, the grass 
is yellow, and the zebras are black and white...

There does seem to be an animal that is confused by the stripes of 
zebras (though probably not by the colors either). That's the tsetse 
fly. Unlike (the TV told me 15 years ago) all other tropical African 
mammals, horses in general are not immune to *Trypanosoma*.

>  Let's see here. 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.

Well, *Sinosauropteryx* obviously didn't live in trees...

>  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.

Dunning-Kruger effect. Testing all these assumptions is a lot more 
difficult than you have ever imagined.