[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Why Did Mammals Survive the 'K/T Extinction'?
On Feb 3, 2010, at 9:24 AM, John Bois wrote:
...this assumes that few or no dinosaurs burrowed, and that all
surviving
mammals did. It also assumes that all surviving birds burrowed or were
cavity nesters. Below are two web sites reporting probable dino
burrows in
Montana and Australia. A good question is: some dinosaurs were
living in and
had adapted to extreme environments (the arctic, for example). Why
didn't
they survive?
I agree; that is good question. As a potential, partial answer: the
scenario you provided is only asserted if one supposes the conditions
were so extreme as to be deterministic. That is, a "burrow or death"
scenario (Izzard's "cake or death" routine comes to mind...) On the
other hand, if we presume that the effects were more probabilistic in
manner, then we might derive a better match to the observed patterns.
If burrowing in dinosaurs was rare, and resources after the impact
were highly limited, then being a dinosaur might make your chances of
survival very low - they aren't zero, because you might be in the
right place at the right time, but the likelihood is very low -
meaning that only a small number are lucky. By contrast, if burrowing
was common in mammals, and small size was also common (latter is
pretty well known), then the amount of survival left to "luck" is lower.
Cheers,
--Mike
Michael Habib
Assistant Professor of Biology
Chatham University
Woodland Road, Pittsburgh PA 15232
Buhl Hall, Room 226A
mhabib@chatham.edu
(443) 280-0181