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From: ncramer@bbn.com (Nichael Cramer)
Newsgroups: sci.astro,sci.space,sci.space.shuttle
Subject: Re: Asteroids and Dinosaurs (was Re: asteroid almost hits earth)
Message-ID: <40227@bbn.COM>
Date: 20 May 89 06:36:07 GMT
References: <256@ringwood.Morgan.COM> <3200009@hpindda.HP.COM> <1212@irisa.UUCP> <40171@bbn.COM> <1493@optilink.UUCP>
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In article <1493@optilink.UUCP> cramer@optilink.UUCP (Clayton Cramer) writes:
>In article <40171@bbn.COM>, ncramer@bbn.com (Nichael Cramer) writes:
># #Does anyone knows others example of strange disappearance ?
># 
># I don't remember the numbers (in species/yr) offhand, but I've read
># arguements (e.g. by S J Gould) that claim that we are *now* in the midst of
># the one of greatest (if not in fact _the_ greatest) of mass extinctions of
># all time.
># 
># If I recall right, the numbers work out to ~1 species/100,000 increase in
># human population.
>
>I've read that the current rate of extinction is about 15 species/century --
>which is clearly far lower than ~1 species/100,000 increase in human
>population.

CLAYTON

I checked my source for the above after I got home last night, and he was
claiming a loss of 10,000 species/yr but he didn't cite any sources.  This
does sound very high.  But on the other hand, it seems equally difficult to
believe we've only lost 13-14 species in all of the 20th century.  (I've
also seen figures in the 1-10/yr range.)

Do you (or anyone else) have specific references for what the actual value
of this rate is?

Thanks
NICHAEL