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Re: Endothermy, UCP1 gene deletion, and the origin of birds



Thanks for the references on UCP1.

Newman based his paper on this earlier one:

http://www.springerlink.com/content/mw3311u630050p83/

BMC Biology
Volume 6, Number 1, 17, DOI: 10.1186/1741-7007-6-17

The brown adipocyte differentiation pathway in birds: An evolutionary road
not taken

Nadejda V Mezentseva, Jaliya S Kumaratilake and Stuart A Newman


What do you make of it?


>
>> In his new paper Stuart A. Newman
>> offers an interesting, if unclearly stated, hypothesis of
>> bird origins. He proposes that it could have occurred due to
>> the loss of the mitochondrial gene UCP1
>
> First and most obvious question: expression profile of UCP1 in crocs,
> squamates and frogs? (Apparently unknown at present)
>
> If we learned anything from the "aggression gene"  and the "gay gene" and
> the "monogamy gene" (which were refuted when evolutionary aspects were
> considered, if not earlier), it would be nice if people stopped publicly
> speculating about the evolutionary role of this or that gene. That was OK
> in the 1980s, but by now there are ways to actually study such questions
> rather than to merely ponder them. And by now there are places for
> speculation other than scientific journals.
>
> Newman may have a point, but it's not even a hypothesis. For a hypothesis
> you need actual data, not some vague notion. And actual data is apparently
> what's lacking here. UCP1 is ubiquitious in vertebrates - it obviously
> evolved in poikilotherms (it may be very old, as the UCP family is even
> found in plants). What was its function there? Nobody seems to know at
> present, or at least I did a quick lookup and couldn't even find an
> expression profile for _Xenopus_. And for all we can say, IF avUCP (avian
> UCP) is not the functional equivalent of UCP1 in birds, UCP1 is not as
> crucail as it might look (which is also supported by
> http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.0020129).
>
> What we can definitely say is that UCP1 is not "the brown fat gene" or
> "the thermoregulation gene" - if anything, that's what *mammal* ancestors
> co-opted it for.
>
> Essentially, we're still stuck at
> http://www.springerlink.com/content/7275607621356t7g/ and
> http://www.sciencedirect.com/science/article/pii/S0005272808000480 (and
> for a more recent summary, see
> http://people.usd.edu/~dlswanso/Pubs/Swanson%202010%20Current%20Ornithology.pdf)
>
> If one is not a prima facie geneticist and talks to people who are, the
> question "what's your taxon?" can work wonders. Molecular genetics has
> still such a high input(funding/time)/output ratio that most researchers
> can't afford to look beyond the scope of one or very few spe