RE: Impacts and ETs

["Thomas R. Holtz, Jr." <tholtz@geol.umd.edu>]

> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> Joe Cantrell
>
> Assuming, as most people do, that Chicxulub was responsible for the K-T 
> extinction, which paved the way for mammalian
> radiations culminating in high intelligence, how would the apparent 
> dependence of the latter on a pure chance event
> affect estimates of the frequency of intelligent life in the Galaxy?
>

Well, given our fantastic sample size of inhabited planets, we can say that it 
decreases the frequency by exactly 2.376%...  Plus or
minus 100%.

Seriously, this question (although interesting) can only be approached with 
massively huge, ultra fast arm waving. This is a science
fiction question, not a science question. (That doesn't mean it is a BAD 
question: I am a long time science fiction fan!!)

So we can't constrain ANY of the variables in this. As others have pointed out, 
we have no evidence that the K/T extinction was
necessary for the evolution of intelligence. It might have evolved if the 
dinosaurs had stayed in charge, either among the dinosaurs
or among the primates (who may well have evolved into recognizably primate-y 
things even with the K/T extinction).

Hope this helps,

                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
        Mailing Address:
                Building 237, Room 1117
                College Park, MD  20742

http://www.geol.umd.edu/~tholtz/
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