Re: DNA news stories: bird and mammal evolution

[Ronald Orenstein <ornstn@home.com>]

At 09:09 PM 05/07/01 +0200, David Marjanovic wrote:
> In the above way. Just found a
> paper in the newest Naturwissenschaften --
> there is genetic evidence for the traditional placement of turtles
> (even
> though that paper can't exclude placing them next to crocs). Of course,
> I've
> forgot the ref... :-] It also says that mtDNA is generally less
> reliable,
> though I forgot why.


 From the Springer web site:

Naturwissenschaften

Abstract Volume 88 Issue 5 (2001) pp 193-200
DOI 10.1007/s001140100228 
review article: The evolutionary position of
turtles revised
Rafael Zardoya (1), Axel Meyer (2)
(1) Museo Nacional de Ciencias Naturales, José Gutiérrez Abascal 2, 28006
Madrid, Spain E-mail: mcnr154@pinar2.csic.es Phone: +34-91-4111328 Fax:
+34-91-5645078
(2) Department of Biology, University of Konstanz, 78457 Konstanz,
Germany
Published online: 17 May 2001
Abstract. Consensus on the evolutionary position of turtles within
the amniote phylogeny has eluded evolutionary biologists for more than a
century. This phylogenetic problem has remained unsolved partly because
turtles have such a unique morphology that only few characters can be
used to link them with any other group of amniotes. Among the many
alternative hypotheses that have been postulated to explain the origin
and phylogenetic relationships of turtles, a general agreement among
paleontologists emerged in favoring the placement of turtles as the only
living survivors of the anapsid reptiles (those that lack temporal
fenestrae in the skull). However, recent morphological and molecular
studies have radically changed our view of amniote phylogenetic
relationships, and evidence is accumulating that supports the diapsid
affinities of turtles. Molecular studies favor archosaurs (crocodiles and
birds) as the living sister group of turtles, whereas morphological
studies support lepidosaurs (tuatara, lizards, and snakes) as the closest
living relatives of turtles. Accepting these hypotheses implies that
turtles cannot be viewed any longer as primitive reptiles, and that they
might have lost the temporal holes in the skull secondarily rather than
never having had them. 

Note that this is a position the authors had already taken in an earlier
study.

--
Ronald I. Orenstein                           Phone: (905) 820-7886
International Wildlife Coalition              Fax/Modem: (905) 569-0116
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