Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!ut-emx!bill
From: bill@ut-emx.uucp (Bill Jefferys)
Newsgroups: sci.bio
Subject: Re: Reconstructing cells from DNA
Message-ID: <47570@ut-emx.uucp>
Date: 21 Apr 91 14:12:51 GMT
References: <18637@csli.Stanford.EDU> <79788@bu.edu.bu.edu>
Organization: The University of Texas at Austin; Austin, Texas
Lines: 38

In article <79788@bu.edu.bu.edu> colby@bu-bio.UUCP (Chris Colby) writes:
#In article <18637@csli.Stanford.EDU> cphoenix@csli.Stanford.EDU (Chris Phoenix) writes:
#>Non-genetic changes in cells might be hereditary.
#
#	This is like saying non-blue balls might be blue. If something
#is hereditary, it must be genetically based (although it would not
#neccesarily have to be genetic material in the form of nucleic acid).
#
#>In the case of sexual reproduction, I would expect that such changes
#>would be passed on only through the mother.
#
#	Why?
#
#>Is this totally off base, or is non-genetic evolution a possibility?
#
#	It's totally off base ;-) Non-genetic evolution is an
#oxymoron.

Actually, Chris P. is not so far off as one might think.
_The Economist_ had a story this week (in the science section)
about a certain species of wasp that reproduced parthenogenetically;
all of the offspring are female. Yet, if the wasps are fed 
antibiotics, they will produce males and females in 50%
ratio. Why? It appears that a bacterium has co-evolved
with the wasp. It is transmitted via the eggs (see Chris
P's speculation above!!!), and has evolved the ability to
supress the production of male offspring. Presumably this
is because it provides an advantage to the bacterium!
Yet the wasp retains the ability to produce males, so it
is the _conditions_ under which the embryo develops
that determine the sex. A non-genetic "evolution" that
"breeds true" as long as the bacterium is present.

Bill Jefferys

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