Re: Extinction

["Larry Febo" <larryf@capital.net>]

-----Original Message-----
From: philidor11 <philidor11@snet.net>
To: larryf@capital.net <larryf@capital.net>
Cc: Dinosaur ListServer <dinosaur@usc.edu>
Date: Thursday, March 30, 2000 7:50 AM
Subject: Re: Extinction


>>> I don`t know much about La Brea, but I can`t see how any determination
of
>extinction by climate change can be made by studying one site alone. Sure,
>one may see that a species was in decline in that area. Sure, one can also
>see that climate was perhaps "deteriorating" in direct correlation at that
>particular site. But what is to say that the species in question didn`t
just
>migrate out of there?<<
>
>Permit me a guess:
>--species have a range, defined as the area with sufficient survival
>resources;
>--the total population of the species increases until it reaches an optimal
>number throughout the range.
>If a population of a species already at the optimal number throughout its
>range migrates out of its portion of the range into another portion, there
>will be competition until the population has been reduced to the optimal
>number again in that area.  The net result of migration would be a
reduction
>in the total number of individuals of the given species.
>Seems logical, no?
>


Maybe reduction in numbers, but....total extinction?? Seems less likely.