From: Derek Gatherer (d.gatherer@vir.gla.ac.uk)
Date: Tue 04 Oct 2005 - 09:47:54 GMT
Ted
At 23:41 02/10/2005, you wrote:
>Gene theory, on the other hand, has virtually nothing to say about
>ontogenesis. Researchers can only point out that a particular gene
>corresponds to a particular trait and that this effect follows from the
>presence of a particular protein. So, the gene that results in brown eyes
>provides the template for the enzyme that catalyzes the relevant pigment.
>That's it. No gene for how the eye is to be structured, what its parts are
>or how they're assembed, just a template for a protein that influences its
>appearance. No blueprint, no developmental program, nothing of consequence
>to the emergence of bodies from eggs. Lacking any compelling reason as to
>why we should reduce the organism to its genes, we have no reason to reduce
>evolution to the transmission of genes.
This is a late-1940s view of developmental genetics. Beginning in
the early 50s with Ed Lewis's work on the genetics of body plan in
Drosophila through to Jani Nusslein-Volhard and Eric Wieschaus's
molecular isolation of those genes from the late 70s onwards, it has
been possible to define the blueprint for how to make a fly from an
egg. Lewis, Nusslein-Volhard and Wieschaus shared the Nobel Prize
for this in 1994. Since the late 80s, Nusslein-Volhard has been
repeating the successful paradigm for the development of the
zebrafish. These genes do structure eyes, they do program
development, they are of major consequence for the emergence of
bodies from eggs. You can mess around with them and produce flies,
fish or frogs with all kinds of tailor-made odd developmental programs.
There are literally 100s of references I could give you. Try this
one for a start on eye development:
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