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Re: Extinction

At 09:59 PM 3/21/00 -0500, John Bois wrote: 
> 2) Nonetheless, if a bolide hit, and apparently one
> quite definitely did, there were a lot of unlucky
> frogs on that day.

But there is _no_ evidence of this.  How can you say ot happened if you
have no evidence.

Actually, there is a *great* *deal* of evidence that a bolide struck the Earth at about 64 MYBP. There is a probable crater, there are impact tektites, there are enrichments in sidereal elements, there are now fullerenes with sidereal elements trapped in them from the boundary. Now, *given* such a major bolide strike, it is *certainty* that it killed many, many frogs, at the very least those living near where the bolide landed. This is a simple matter of physics - no living thing could survive anywhere *near* the impact site.

The debatable issue is whether the impact was, by itself, a *sufficient* cause for the total extinction of non-avian dinosaurs. (For instance, I suspect that the bolide was so effective only because the ecosystems of the Earth were already stressed from other causes, and the same bolide striking at, say, 34 MYBP would have had little long-term effect).

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May the peace of God be with you.         sarima@ix.netcom.com