Re: What about the Neo-Lamarkism idea ?

Francois Sabot wrote:
>
> As far as we known, the general accepted theory about evolution is the
> Darwinian evolution, based on natural selection of the most adaptated
> individuals. Lamarck had previously proposed the theory of adaptation, where
> the individuals adapt themselves to the environment change.
>
> So, in Lamarck, there is a "shock" (genomic, genetic, environement,
> pathogenesis), and then the individuals change to adapt.
> In Darwin, there are mutations, then a "shock", and only individuals with
> the right genomic combination can survive.
>
> This is a basic definition, but which could be suitable for my purpose.
>
> During the last 10 years, more and more analyses on genomic shocks mainly
> had shown that there are a lot of modifications induced by the shock itself.
> This has lead to the so-called "neo-lamarkism" theory, ie that some genetic
> elements (mainly transposable elements) are able to change the genomic
> environment and the genic/genomic combinations of an individual to allow it
> to survive in case of a very large shock. We can also explain this by the
> following sentence: "As we will die, why not attemp to change ourselves
> higly quickly to find a new possibility of survival?"
>
> What about your comments and ideas about this theory ?
>
> F Sabot, PhD


We just had a short but interesting discussion about neo-lamarckism in
talk.origins in the thread "E. Coli and Self-Evolution" started
7/21/2005. See the subthread started by dkomo there.

The general consensus was that an increase in mutation rate in e. coli
due to environmental stress is not neo-lamarckism, but darwinism as
usual. To have true neo-lamarckism, there must be *directed*
mutations caused by environmental cues. These types of mutations are
rather rare. See the post by hersheyh in that thread for some examples
of apparent directed mutations.

My conclusion was that neo-lamarckism is so rare because it is not
very efficient and the chemical pathways needed to make highly
specific changes to the genome are too difficult to evolve.


--dkomo@xxxxxxxx

.

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