Re: Bristles before down: A new perspective on the functional origin of feathers

[Jaime Headden <jaimeheadden@gmail.com>]

Also without having read this, I am curious:

Isn't the "bristle first" argument already the rpevailing theory of
the origin of avian feathers? That is, Prum's Stage I, as demonstrated
in the form of "pycnofibers" in pterosaurs, are a bundle of closely
bunched filaments, arranged "en masse." This isn't a problem, if it
occurs prior to the appearance of feathered dinosaurs, as a precursor.
It agrees with feather development.

On Tue, Mar 10, 2015 at 9:10 AM, Ben Creisler <bcreisler@gmail.com> wrote:
> Ben Creisler
> bcreisler@gmail.com
>
> A new online paper:
>
> W. Scott Persons IV and Philip J. Currie (2015)
> Bristles before down: A new perspective on the functional origin of feathers.
> Evolution (advance online publication)
> DOI: 10.1111/evo.12634
> http://onlinelibrary.wiley.com/doi/10.1111/evo.12634/abstract
>
> Over the course of the last two decades, the understanding of the
> early evolution of feathers in non-avian dinosaurs has been
> revolutionized. It is now recognized that early feathers had a simple
> form comparable in general structure to the hairs of mammals. Insight
> into the prevalence of simple feathers throughout the dinosaur family
> tree has gradually arisen in tandem with the growing evidence for
> endothermic dinosaur metabolisms. This has led to the generally
> accepted opinion that the early feather coats of dinosaurs functioned
> as thermo insulation. However, thermo insulation is often erroneously
> stated to be a likely functional explanation for the origin of
> feathers. The problem with this explanation is that, like mammalian
> hair, simple feathers could serve as insulation only when present in
> sufficiently high concentrations. The theory therefore necessitates
> the origination of feathers en masse. We advocate for a novel origin
> theory of feathers as bristles. Bristles are facial feathers common
> among modern birds that function like mammalian tactile whiskers, and
> are frequently simple and hair-like in form. Bristles serve their role
> in low concentrations, and therefore offer a feasible first stage in
> feather evolution.



-- 
Jaime A. Headden
The Bite Stuff: http://qilong.wordpress.com/


"Innocent, unbiased observation is a myth" - P. B. Medawar (1969)