INTERNATIONAL INSTITUTE
OF BIOPHYSICS
Conference
on Biophotons 1999
Abstracts of the Conference Reports in
alphabetic Order
THE IMPLICATION OF THE STATISTIC ANALYSIS TO UNDERSTANDING THE
MORPHOGENSIS
V.A. Scobeyeva and V. G. Cherdantsev
Evolution Theory department, Faculty of Biology, Lomonosov Moscow
State University, Moscow 119899, Russia
Almost a hundred years ago Alexander Gurwitsch stated that the normal
individual variability of morphogenesis can be treated as a "Naturexperiment"
(Gurwitsch's term) which is in many respects has an advantage over laboratory
experiments. Our statistical analysis of the individual morphological variability
of gastrulation in a few amphibian species has confirmed that the variability
of embryonic structures in the process of their formation is of a higher
order of magnitude than the variability of the same structures at definitive
stages of their development. The normal course of morphogenesis is subject
to fluctuations which the order of magnitude is compatible with that of
an experimental intervention. This suggests an identity between the normal
development and its regulation.
We have revealed the following general properties of the morphogenetic
individual variability. With the origination of a new morphological structure
(for example, the blastopore lip of a gastrula) the characters of this
structure arise and vary independently. The statistical analysis shows
their origination to be arising as a result of random fluctuations that
go beyond the scope of the initial system of morphogenetic bonds. At the
next phase there appears a new coherent system of morphogenetic bonds which
corresponds to the development of a new structure as a whole, this leading
not to the decrease but to the increase in the amount of variability. The
characters of a new structure are preponderant both in their variability,
as compared to any other characters of the embryo at a given developmental
stage, and in the rates of their change. If they were the definitive phenotypic
characters, this would have been possible only provided that any given
character of a new structure had a feeble correlation with the other morphological
characters of a gastrula. The converse is true when considering structures
in the process of their formation. This is the case when these are correlative
changes in newly arising and rapidly developing characters of a new structure
that make a preponderant contribution into the variability of a system
as a whole. This provides a reason to make a distinction between characters
of a new structure fluctuating at random and its directional change on
the basis of the origination of closed loops of a positive feedback between
unidirectional fluctuations of characters. It follows that the increase
in the variability scale provides an opportunity of the reduction of variables
which are neccessary for understanding the general trends of morphogenetic
processes, this permitting to separate the basic variables of morphogenesis.
With the completion of a new structure formation the variability in its
characters is subject to decrease, this being connected to the partition
of a system into new blocks of characters with an attenuation of a mutual
interaction. Then inside these blocks there repeats the described scenario
of the variability dynamics.
The statistics laws of the dynamics of morphogenesis are coincident
with a statistics of any non-linear processes capable of self-organization
thus providing a "conclusive evidence" of a recruitment of self-organization
into the "information loaded" processes in the biological morphogenesis.
© International
Institute of Biophysics 2001 E-mail: iib@lifescientists.de
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