Re: Mammal competency.

[John Bois <jbois@umd5.umd.edu>]

On Mon, 13 May 1996 jrw6f@faraday.clas.virginia.edu wrote:

>         I would certainly never argue that extra-biotic influence is
> required for extinction, and I am willing to submit that many species
> do become extinct, effectively by being "out-competed".

And yet a general bias exists among people who care what happened at the 
K/T against biological causation.


>  I believe it is more likely that a montage of events aside from
> direct pressure of another organism are also culprits in most
> extinctions, such as, competition+disease, or competition+climatic
> change+random genetic quirk that allows one species to gain a
> decisive advantage while the other is weak, etc.  The point being
> that "out-competition" has to accomplished *BEFORE THE TARGET
> SPECIES CAN ADAPT*.

A rapid, hopeful monster is possible.  A gradual accumulation of diverse 
predators of eggs is more likely.

> The point of my posting (or one of them, at least), was that
> what applies to a species does not always apply to a group.

You're denying me my only trump: the very thing that applies to dinosaurs 
AS A GROUP is the egg.  

> While you have followed a logical approach in setting up your murder
> mystery, with a putative weakness in the victim, and a strength in
> the alleged killer.  As I mentioned in my previous posting, you have
> not explained why evolution, the "police" as it were, did not step
> in sooner to stop the crime.

I did, in an earlier post, hypothesize that dinos were naive to mammal 
predation until the "moment" that mammal defences, built in response to 
dino predation, became offensive weapons.  In this sense, they resemble 
the invasions of islands where they destroy species which have had no 
time to respond (adaptively).