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Re: Dinosaurian biology and sexual selection
>>It is not made clear why, if these structures are for sexual display, in
>>ceratopsids they change so significantly through ontogeny:
Perhaps it makes a more dramatic signal of sexual maturity than just increasing
the size would?
----- Original Message -----
From: "Denver Fowler" <email@example.com>
Sent: Friday, October 29, 2010 11:59:34 AM GMT -06:00 US/Canada Central
Subject: Re: Dinosaurian biology and sexual selection
n Fri, Oct 29, 2010 at 4:45 AM, <firstname.lastname@example.org> wrote:
> From: Ben Creisler
> In case this new paper has not been mentioned yet:
>> K. Padian & J. R. Horner (2010)
>> The definition of sexual selection and its implications
>> for dinosaurian biology.
>> Journal of Zoology (advance online publication)
>It is also worth noting that Knell and Sampson have written a reply to
>that paper in the same journal:
No. The Knell and Sampson rebuttal is to:
Padian, K. & Horner, J. (2010a). The evolution of ââbizarre structuresââ in
sexual selection, social selection, or species recognition? J. Zool. 283
(Online DOI: 10.1111/j.1469-7998.2010.00719.x.)
The upcoming Padian/Horner (2010b) paper on sexual selection points out the
differences between sexual slelection as originally defined, and its current
usage, and how this changes the way we interpret dinosaurs.
It's interesting that Knell and Sampson do not use the new term presented by
Padian and Horner (2010a): "social signaling". Instead they use the old term
"species recognition", which I agree has some inherent interpretation problems.
The reply also makes some interesting diversions from the usual
cladogenesis-driven allopatry models of Sampson et al.
The social signaling hypothesis actually makes a lot of sense, but I think you
really have to use a high-resolution record to test it. You also need more up
date phylogeny, and an understanding of when cladogenesis actually happens, and
the potential roles of phylogenetic inertia.
It is not made clear why, if these structures are for sexual display, in
ceratopsids they change so significantly through ontogeny: surely they would
just start out with small horns, then get bigger (more like hadrosaurs). Why
change the orientation? downsize/resorption? none of this is accounted for by
the sexual selection only hypothesis.