in vitro evolution?

Paul Arveson (
Fri, 12 Dec 1997 16:57:50 -0400

Thanks for your good, technical discussion on _Isoetes_. They are
an ancient genus, and I didn't realize they were so genetically complex.

I wanted to ask you (and others) about some of the recent articles in
Science regarding 'experimental demonstrations of evolution.' I don't have
the references, I have seen 2 or 3 I have seen in the past few months,
written by 'evolutionary biologists'. Their experiments all claim
demonstrations of evolution in vitro, with no micro/macro qualifications.

In one of the experiments, E. coli were deprived of certain sugars, and
over the course of several generations, strains emerged that were able to
metabolize another sugar. This they described as a form of 'natural
selection' and hence evolution. Couldn't we also interpret this as
amplification of a metabolic system based on pre-existing DNA?

I wonder whether perhaps these 'evolutionary biologists' are begging the
question, assuming what they are trying to establish experimentally. I say
this as a purely scientific question; I have no intense need to falsify
evolution but I certainly have been sensitized to the biases (pro or con)
that exist on the question. Is it fair to criticize the conclusions of
these experimenters? Is there an experimental test that would demonstrate
'real' evolution and that can be done on a short time scale?

Paul Arveson, Code 724, Research Physicist, Signatures Directorate
Naval Surface Warfare Center, Carderock Division
9500 MacArthur Blvd., West Bethesda, MD 20817-5700
(301) 227-3831 (301) 227-4511 (FAX)