variable mutation rate

[Andrew_Maillet]

Agner Fog <----Remove-to-reply----Agner at login.dknet.dk> wrote in article
<6db26a$5ri at net.bio.net>...
>.... 
> Is there any evidence that any organisms 'actively' increase their
mutation 
> rate under adverse conditions?  By 'actively' I mean a specific evolved 
> mechanism for regulating mutation rate, as opposed to haphazard
mechanisms such 
> as the organism having less resources for DNA repair when starving.
> 
> I haven't found any such evidence in the litterature. If it exists then
please 
> point to the reference.
> 
>
====-------------------------agner at login.dknet.dk-------------------------==
==
> Agner Fog, Ph.D.                 See my electronic book: 'Cultural
Selection'
> Denmark                          at:   http://announce.com/agner/cultsel
> 
>

I believe that Barbara Mclintock's work in maize showed an activation of
transposable elements in response to environmental stress.  I am not
entriely familiar with this work and it may be, as you say a haphazard
mechanism due to a lack of control resources.

Andrew Maillet

University of Massachusetts Medical Center
Worcester Massachusetts 01655