Biology Reference
In-Depth Information
In general, all the elements of ontogenesis which are added to
genetic determinism are called 'epigenetic factors', some authors
going so far as to reintroduce Lamarckian type mechanisms
(Jablonka and Lamb, 1995).
There is a question that must be asked here. Is a simple
rearrangement of the genetic theory enough to solve the problem
which confronts it, or is a complete change of conceptual frame-
work necessary? Indeed, what is being questioned is the very heart
of this theory. The problem raised by Morgan is that of the speci-
ficity of the relationship between genes and the characteristics
associated with them. If this relationship is not specific, we cannot
assert that genes determine characteristics. They may certainly
form an important part of the process of embryogenesis which
builds these characteristics, but they are not the cause in the sense
implied by genetic determinism. Epigenetic mechanisms being
added to the action of genes changes nothing regarding this fact
(Kupiec, 2001).
This problem is exactly the same as the problem of the stereo-
specificity of molecules. For the relationship between a gene and its
phenotypic characteristic to be specific, the underlying molecular
mechanisms must be specific too. However, we have seen that
analysis of the action of genes at molecular level, far from resolving
the problem, only amplifies it. We must then ask ourselves why,
when the absence of specificity in the way the gene acts has already
been demonstrated, has this postulate not only been maintained,
but has even been extended to the molecular level? Why, too, when
the non-specificity of molecular interactions has been demonstrated
time and time again, do biologists transfer the property of speci-
ficity to the macroscopic level without concern for the theoretical
incoherence that this represents (see chapter 4), instead of chang-
ing the theory? According to the usual criteria of scientific practice,
a theory which has been invalidated in such a radical manner
should be abandoned.
There is something very important for biology in regard to this
question which differentiates it from physics and explains its diffi-
culty in going beyond hylemorphic ontology. The underlying problem
