> David Tyler responds:
> > .. .. it does appear to me
> > that genetic reductionism is very strong among biochemists.
Tim wrote:
> I had this discussion previously with Brian Harper. Since then,
> I decided to do an (admittedly unscientific) review/survey of
> the biochemists/mol. biologists/physiologists (& etc.) who
> I know personally. None believe that "genes control everything".
This is certainly a surprise to me - a pleasant one, I hasten to add!
> So where does this general impression that genetic determinism
> and hard-core genetic reductionism enjoys overwhelming support
> among biologists arise? I suspect that is has a lot to do with
> many writers (scientists) not been too careful with their words
> and trying to oversimplify the issues. This seems particularly
> true in articles written for the popular press but I've also seen
> it in some journal articles.
I wonder if this is understated for the technical literature: there
is a tremendous emphasis on genes, almost to the exclusion of other
aspects. This is perhaps not unrelated to the funding of research.
The Human Genome project may be conveying this emphasis - perhaps
more because of the influence of James Watson.
> Another factor is the basic tendency
> of scientists to use reductionist approaches in their work.
> That's just science - Things work *a lot* easier if you can
> achieve "a reduction" in explanation. So, even though problems
> may not be easily reducible to simpler ones, such an approach
> will still be attempted and will always garner the most
> interest when successful (read: publications). "Unreduced" problems
> don't get much press -- After all, how much is there to say about
> a problem you can't crack?
This is a less appealing reason. Those who do not think the genome
plays the architects role are no less committed to finding causal
explanations of phenomena.
> By far, the majority of biologists know that everything does not
> revolve around DNA. It's just the focus of such intense study
> because it's something relatively easy to investigate.
I welcome these comments - a breath of fresh air!
Regarding agreement with the quote from Harold:
> Actually, yes, if strictly interpreted. I ran this quote past
> a few enzymologists, physiologists and molecular biologists at
> work. They agreed too.
I am genuinely surprised - pleasantly so! I requote two lines from
Harold:
> > "Most microbiologists look to the genome to play the architects role.
> > From where we now stand, this seems to me a rejection of reason.
You responded:
> I like that reference except for the "rejection of reason" part in
> the second paragraph. I think he's stretching things a bit.
I would have expected you to dissent from the "Most microbiologists"
part as well. Is this the case - or has the change occurred since
Harold wrote? I am persisting with this thought because only a year
later, a significant paper appeared in Developmental Biology which
set out "an alternative to the solely genetic model of evolution and
development". At that time, the authors were advancing something
new! Here is an extended quote:
"Just as the cell is seen to be the unit of structure and function in
the body - not the genes that act through it - so the morphogenetic
field can be seen as a major unit of ontogenetic and phylogenetic
change. In declaring the morphogenetic field to be a major module of
developmental and evolutionary change, we are, of course, setting it
up as an alternative to the solely genetic model of evolution and
development. This, however, is not to be seen as antagonistic to the
principle that genes are important in evolution or development. This
is not in any way denied. But just as the genes make the cells and
the cells form the body, so the gene products first need to interact
to create morphogenetic fields in order to have their effects.
Changes in these fields then change the ways that animals develop."
(page 368).
Gilbert, S.F., Opitz, J.M. and Raff, R.A. 1996, Developmental
Biology, 173, 357-372.
> Do genes play a role in development and cell biology? Yes. Is
> the role of a particular gene (or genes) strongly deterministic?
> Sometimes yes, often no. Are there times when a trait cannot
> arise without some genes or combination of genes? Definitely.
> Do the above opinions make me a genetic determinist or genetic
> reductionist, and does my position require a "rejection of
> reason"? I suspect not, but YMMV.
I would answer these questions in the same way.
Is there a UK vs US divide here? In the UK, vocal people are
Dawkins, Maynard Smith and earlier James Watson. Brian Goodwin has
tended to be a lone voice. Yet in the States you have a greater
diversity of opinion on these matters.
I had written (to your aside):
> > Yes. I do find it interesting that there are great divergencies
> > of thinking between people who nominally have the same belief
> > system. We see it in Christian circles and we see it in Marxist
> > circles.
You replied:
> That's because we are genetically programmed to compete. It's
> a direct consequence of Darwinian evolution ;*)
Aha - the ultimate explanation! Darwinian storytelling at its best!
(I think it is more to do with the American temperament, myself,
with longings for the wild west and shoot-outs!)
Best regards,
David J. Tyler.