Re: mammal mystery

[Jeffrey Martz <martz@holly.ColoState.EDU>]

> << Asteroids have been smacking the earth with much greater frequency.
>  Humans are a one-shot quirk. >>
> 
> But humans >have< hung around for longer than a typical asteroid impact...

      That is what I mean; they are different.  I'm talking about the
differing natures of the catastrophie, and the presumably different
effects on extinctions in a global, regional, and taxonomic sense.  If the
objective is to try to understand patterns of extinction in the Earth's
past, there is no reason to think that human-caused extinctions (being an
unprecedented phenomena of the last couple hundred thousand years) are a
good model for ANY previous extinction.  

LN Jeff
O-