Biology Reference
In-Depth Information
The concept of probability will first of all be analysed in order
to understand the difference between determinism and probabilism.
This prior clarification is necessary in order to grasp what the
intrinsically probabilistic character of cellular Darwinism involves,
and to differentiate it from the theories of genetics and self-organisation.
The latter use the concept of noise or fluctuation but are funda-
mentally deterministic theories (chapter 2). The principles of
genetic determinism will also be studied in detail. We shall see that
they are incompatible with recent experimental data because the
molecular order that they imply for explaining biological organisa-
tion does not exist (chapters 3 and 4). We shall then examine the
variants of holism, theories which assert that order, instead of orig-
inating from the molecular level as in genetic determinism, origi-
nates from higher levels of organisation. The analysis will show
that they are not valid alternatives, as they rely on the idea of
a creative nature and a return to animism, which are purely and
simply a negation of scientific rationality (chapter 5). We will then
discuss ontophylogenesis, which differs from reductionism and
holism in that it does not presuppose origin in biological organisa-
tion, whether concealed at molecular level or at higher levels of
organisation. As a result, ontogenesis can really be considered as a
process and not as the expression of a static order. The experi-
mental data supporting it have been accumulating for more than
forty years. They show that gene expression is a probabilistic phe-
nomenon and that there exist mechanisms exerting selection on cell
differentiation. In addition, computer simulations show that cellu-
lar Darwinism is in a position to generate reproducible cell struc-
tures and that chance can play a positive role in this process
(chapter 6). Finally, ontophylogenesis will be placed in a wider his-
torical and philosophical perspective, which will distinguish it
as much from Aristotelian (hylemorphic) conceptions, which place
the origin of organisation in Form, as from Hippocratic conceptions
that place it directly in the material body taken as a whole.
This analysis will again show how it differs from genetics and self-
organisation which, for their part, remain within these traditional
modes of thought (chapter 7).
