tonmaas at xs4all.nl (Ton Maas) wrote:
"" Modern
"" day emphasis on genes as informational carriers of the "blueprint" of
"" organisms, for instance, is still largely unaware of the implications of
"" research done by D'Arcy Thompson (who showed that evolution is actually
"" saturated with patterns that are highly constant between species - such
as
"" a nose above a mouth and an eye and an ear on eiter side - and which are
"" analogously coded rather than digitally)
Not entirely true, I fear. The homeobox gene as the switch that turns on an
architectural element is well-established and increasingly understood. The
creation of a sufficient mass of homeobox modules is thought to lie behind
the Cambrian radiation, in which many strange and now-extinct body plans
were tried out. The Burgess shales, for example, contain their remains.
This is not pedantry (I hope), but relevant. Evolution is partly conducted
at the level of the genotype (drift, accumulated mutation, cascade
establishment, inter-genotype exchange and deletion) and also at the level
fo the phenotype, the physical expression of the genes at the level of the
individual. It is also conducted at the level of the species within its
ecology (how the mass behave) and in terms of non-genetic - cultural -
transmission. The neat little divisions with which we used to be
comfortable are blurred when we see reality somewhat more clearly. The same
has to be true of the software-hardware divide; and other academicisms that
we impose on what just is.
______________________________________
Oliver Sparrow
