Re: [asa] Lab speciation

Near neutral mutations, which are either slightly beneficial or
detrimental are an important source for evolutionary variation. They
are often too subtle to be under strong selective pressures and their
near neutrality means that their effects can be minimal. Over time
such near neutral mutations however can combine with other mutations
to result in a more substantial benefit. To me the most important
factor to the 'success' of evolution, is the evolution of neutrality.
These concepts have been explored since Motoo Kimura proposed the
neutral theory followed by Ohta who proposed the near neutral theory.

Pim

On Wed, Jun 4, 2008 at 1:59 PM, Murray Hogg <muzhogg@netspace.net.au> wrote:
> Hi Burgy,
>
> In the piece posted, it was the following that most interested me;
>
> <snip>
> ... A few mutations occurred which actually were mildly
>>
>> harmful but did not outright kill the strain. Then a few more
>> mutations occurred that combined with the previously harmful ones to
>> provide a huge net positive benefit.
>
> </snip>
>
> One of the most obvious difficulties in biological evolution - as least for
> a layman like myself - is that the formation of new information within
> genomes (i.e. "mutations") seems almost always to be harmful. And I add the
> "almost" as an exercise in charity - every mutation I'm personally aware of
> is detrimental, usually fatal.
>
> This point has always puzzled me as it really seems a block to understanding
> the "how" of evolution. So this strikes me as a very intriguing finding.
>
> A few related questions, however;
>
> (1) Are my remarks re "detrimental, usually fatal" effects of mutations a
> fair assessment of the data - or an expression of ignorance of same?
>
> (2) How does the finding in the snippet from your post (above) strike
> practicing biologists? Is it remarkable or merely mundane?
>
> (2a) If remarkable, is it so because it confirms what has been suspected but
> not experimentally open to confirmation, or because it is actually quite
> unexpected?
>
> (2b) If mundane, am I right in thinking there must be OTHER confirmatory
> examples of mutations which are in themselves harmful, but when taken in
> conjunction with other mutations have provided a net benefit?
>
> Thanks for a very informative piece and I look forward to any constructive
> comment which might be forthcoming on questions (1) to (2b) above.
>
> Blessings,
> Murray Hogg
> Pastor, East Camberwell Baptist Church, Victoria, Australia
> Post-Grad Student (MTh), Australian College of Theology
>
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Received on Thu Jun 5 00:11:11 2008