Biology Reference
In-Depth Information
3
The Determinism of Molecular Biology
S
UMMARY
. In non-living physical systems, macroscopic order
arises from the probabilistic behaviour of atomic particles, the
variance of which is reduced to a negligible level by the law of
large numbers. In genetic determinism in contrast, biological
organisation arises from intrinsic molecular determinism. This
difference in nature between the laws of biology and those of
physics reflects a radical ontological separation between these
two disciplines. For physics, order is just a subjective approxi-
mation, while for molecular biology, it is real and objective.
This is why determinism in biology seems insurmountable.
Biological molecules escape Brownian motion because they are
highly ordered by the genetic information contained in the
DNA. This produces specific interactions between molecules,
allowing them to self-assemble and for the organism to be con-
structed through increasingly complex levels of organisation,
controlled by the genetic programme. For this theory to be valid,
however, it must be subjected to an imperative. Interactions
between biological molecules have to be unequivocal, or very
few in number, in order to exclude chance.
Since we entered the era of post-genomic biology, it is often claimed
that it has become essential for biologists to be interdisciplinary. In
fact, it is worthwhile to recall that interdisciplinary collaboration
has existed since the early days of molecular biology, which consists
of applying physical and chemical methods to biology. Physicists
have been at the forefront in this. The most well-known is probably
Francis Crick, the co-discoverer of the structure of DNA in 1953.
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