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Re: Here's the NYT Mass Extinction article



>    The report suggests that extinctions of all magnitudes, from the
>    smallest to the most devastating, probably had many different
>    causes and that future mass extinctions may be intrinsically
>    unpredictable. 

     Basically what Raup has been saying for years, and in my opinion
right on the mark.  Glad to see there is a more in depth statisticl data
to back it up.

>    Moreover, the impact of an asteroid or a continental blast of
>    volcanic lava may not be needed to kill off a large proportion of
>    the earth's animals and plants, the authors said; relatively small
>    changes in global conditions may sometimes combine in complex ways
>    to precipitate catastrophic consequences. 

     Of course, if meteor impacts (or for that matter, gargantuan
eruptions) are fairly regular events (which they probably are), they would
fit nicely on the same curve along with more mundane things like climate
fluctuations.

>    There is growing evidence that the mass extinction at the end of
>    the Cretaceous period occurred about the same time that a monster
>    meteor struck the Yucatan Peninsula. And yet, efforts to link other
>    major extinctions with similar impacts have largely failed. 

     Impacts are one of many contributing factors to chose from; just
because they played a part in one or a few doesn't mean they contributed
to all.

>    Dr. Raup has argued for more than a decade that most extinctions --
>    minor waves as well as globally catastrophic ones -- result from
>    meteor impacts.

       I don't understand this; the kill curve Raup had in "Extinction;
bad genes or bad luck?" sounds exactly like what these guys put together.
Or does he think the curve has to do ONLY with regular meteor impacts,
with the size of the extinction having to do with size of the impact
alone?
     Could anyone give me the formal reference for this paper?

LN Jeff
O-