Re: HOLOCENE (was: Re: Proposal:New Geologic Era)

[Mark Sumner <range@inlink.com>]

In fact, the only major extinction event for which we can verify the cause
is the current event.  The cause in this case being the presence of a,
purportedly, intelligent species.

Currently, I believe we have achieved an extinction rate that doesn't
quite match the major events of the K-T or Permian-Triassic boundaries,
but we've managed a species depletion that approaches that of the Late
Triassic, and exceeds any other Tertiary kill. (In this I'm assuming that
man had a hand in the demise of the Pleistocene megafauna)

In the grand old tradition of geology, I've always thought that we should
extend this data into the past.  So, the end of the K die out becomes the
result of some overachieving theropods (or exceptionally bright shrews),
while the Permian event must have been caused by Dimetrodons with
doctorates.

The onset of cold weather at the end of the K and Permian is clearly
related to nuclear winter.

Mark
----
DEVIL'S TOWER sampler at http://www.inlink.com/~range

On Wed, 4 Jun 1997, Michael D. Miller wrote:
> > > On Mon, 2 Jun 1997 Tetanurae@aol.com wrote:
> > 
> > There is some currently held belief that we are now in the middle of 
> > a mass extinction (see for example Ward: 'The end of evolution' and 
> > Leakey: 'The fourth extinction), that in fact begun with the 
> > disappearance of the temperate and arctic zone megafauna.
> > I don't want to talk doom, but if things keep going on this way and 
> > at this rate, we will mark a very impressive boundary in the 
> > geological/fossil record...
> > 
> I recently got a look at Earth magazine April 1997 and the June issue of 
> Discover magazine yesterday and one of them had that topic featured.  
> Maybe we are on the edge of a mass extinction.  Time will tell.
>