Re: Extinction

[Dinogeorge@aol.com]

In a message dated 3/24/00 8:21:22 AM EST, philidor11@snet.net writes:

<< Restating your assertion:  A mass extinction can have multiple causes, 
among
 them an asteroid impact.  The K-T mass extinction occurred at approximately
 the same time as an asteroid impact.  Therefore, the K-T mass extinction was
 caused by an asteroid impact. >>

Not exactly right. A mass extinction will have a >single< global cause, not 
>multiple< causes. One such single cause can be asteroid impact. The problem 
with multiple causation is to get all the causes to coincide in their 
effects; the more causes you throw into the mix, the less chance there is 
that your hypothesis will stand. The asteroid impact at the K-T boundary was 
gigantic, with devastating worldwide physical effects whose traces have been 
well documented in the geological record. If you say that this event and the 
K-T mass extinction had nothing to do with one another and are purely 
coincidental, you have to show positively why you are denying the obvious 
conclusion. It is not sufficient to merely list possible alternative causes 
of mass extinctions and assert that they might have caused the K-T extinction 
instead.

We have measured the motion of the moon and have found that it orbits the 
earth from west to east. If you come along and assert that it really moves 
from east to west, and that what we have been measuring is some kind of 
illusion, it is up to you to demonstrate this. Similarly, anyone who denies 
the connection between the K-T mass extinction and the K-T asteroid impact 
must now >show<, not merely >assert<, that these events are disconnected and 
coincidental. (One way to do this, for example, might be to exhibit 
unreworked dinosaur fossils from well above the K-T boundary.)