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Re: Declining pterosaur diversity
On Sun, 28 Nov 2004, Jaime A. Headden wrote:
> John Bois (firstname.lastname@example.org) wrote:
> <Penny, D. and M.J. Phillips 2004 The Rise of birds and mammals: are
> microevolutionary processes sufficient for macroevolution? _Trends in
> Ecology and Evolution_ Vol.19 No.10 pp.518-522.
> Why does half the paragraph have to be about crown groups and wether or
> not we can refer fossils to them?
Alroy's thing is that nothing important happened until the K/T event;
that this lead to a subsequent radiation of mammals that have the signal
traits of extant mammals. Crown groups are important to Alroy, no? And
what about me? I would like a finding of mammals (and birds) that
increase predation/competition pressure over the Cretaceous. Crown groups
would ne nice but not necessary.
> ...the authors support
> the declining diversity they see as evidence for this replacement regime.
> We need more evidence for this, not ghost competitors to explain a problem
> with the extinction scenario.
One of the most important functions of a scientist is to propose testable
and alternate hypotheses. This paper is very much in this spirit.