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RE: AW: New feather-like fossil from the Jurassic of Kazakhstan, Dzik et al 2010
> Date: Wed, 10 Nov 2010 05:19:19 +0000
> From: email@example.com
> To: firstname.lastname@example.org
> Subject: AW: New feather-like fossil from the Jurassic of Kazakhstan, Dzik et
> al 2010
> The "type I to type V" transition scheme (if that's what you mean by
> mainstream model) still assumes genetics hasn't progressed since the model's
> inception (in other word, it has not accomodated a lot of crucial facts that
> were established since its inception) and does not seem to map well on the
> fossil record. Evolution of the final complex branching structure seems to
> have occured in an evolutionary blink of an eye, and quirttre likely
> repeatedly so, after or coincident with prolonged stasis of "protofuzz".
> Undisputable evidence of stages III and IV has not, I think, been found yet,
> and these stages would quite likely be the least advantageous (don't keep you
> warm well, can't flutter-hop with them, maintenance is a nightmare and energy
> expenditure considerable), killing hopes of progress to stage V dead. But
> stage V has been realized at least once and quite possibly more often,
> perhaps far more often.
I wasn't aware that some of the stages were currently disputed. Do you have a
reference for that? According to a paper on theropod feathers published by Xu
et al. last year, "This morphotype is congruent with the stage I morphology
predicted by developmental models, and all major predicted morphotypes have now
been documented in the fossil record. This congruence between the full range of
paleontological and developmental data strongly supports the hypothesis that
feathers evolved and initially diversified in nonavian theropods before the
origin of birds and the evolution of flight."
Xu X, Zheng X & You H, 2009. "A new feather type in a nonavian theropod and the
early evolution of feathers." PNAS 106: 832-834.