Message-Id: <v01540b02af6fefd77421@[192.174.2.170]>
Date: Tue, 8 Apr 1997 13:52:06 +0100
To: pinhole
From: emuller@exploratorium.edu (Eric Muller)
Subject: re: Evolution and a big magnet
>Date: Mon, 31 Mar 1997 12:14:12 -0900
>From: lahr@giseis.alaska.edu (Dr. John Lahr (USGS-GI Seismologist))
>To: emuller@exploratorium.edu
>Subject: Evolution and a big magnet
>Cc: jlahr@polarnet.com
>X-Sun-Charset: US-ASCII
>
>> >Date: 29 Mar 1997 08:09:27 U
>> >From: emuller@exploratorium.edu
>> >Subject: evolution and a big magnet
>> >
>> >To Biologist and Geologist:
>> >The earth's magnetic field changes direction every few hundred thousand
>> >years or so. This field, extends into space and helps keep harmful
>> >radiation from reaching the earthis surface.
>> >
>> >So hereis the question:
>> >Since excessive radiation contributes to mutation of organisms, does
>> >anyone know if there is a direct correlation between magnetic reversals
>> >and evolution? If so, is there evidence in the fossil record that
>> >matches the paleomagnetic record?
>> >
>> >
>> >----------------------------------------------------------------------
>>
>Eric,
>
>I checked with one of the geologists up here at the University of Alaska
>(Professor Rainer Newberry) and he said that he was not aware of a
>documented correlation between extinction events or periods of rapid
>evolution with magnetic reversals. This may be in part because of the
>difficulty of correlating the times of the reversals to the fossil record,
>but it is clear that catastrophic evolutionary changes to not occur
>at the time of every reversal.
>
>JCLahr
>################################## John C. Lahr
>################################# Seismologist
>################################ U.S. Geological Survey
>############################### c/o Geophysical Institute
>############################## 903 Koyukuk Drive
>~~~~~~~~~~~~~~ Get ~~~~~~~~~~ #############################
>###########################################################
> P.O. Box 757320 ################################
> Fairbanks, AK 99775 #################################
> Phone: (907) 474-7997 ##################################
> Fax: (907) 474-5618 ~~~~~~~~ the thrust? ~~~~~~~~~~~~~~
> lahr@usgs.gov ####################################
> http://www.aeic.alaska.edu/Input/lahr/
>
Eric Muller
Teacher-In-Residence
Exploratorium
3601 Lyon St.
San Francisco, CA 94123
415-561-0313
email:emuller@exploratorium.edu