|
ISIS Report 23/10/09
ISIS Lecture
How Development Directs Evolution
Epigenetics and Generative Dynamics
Invited lecture for Evolution and the Future conference, Hotel
Continental-Beograd, Belgrade, Serbia, 14-18 October 2009. Dr. Mae-Wan Ho
A fully referenced version (to be published in Conference Proceedings) and handsomely
illustrated power point presentation are available for download from ISIS
online bookstore. Text version, Text and Presentation
Abstract
and Introduction
In a paper
published 30 years ago, Ho and Saunders (1979) proposed
the then outrageous non-Darwinian idea that the intrinsic dynamics of
developmental processes is the source of non-random variations that directs
evolutionary change in the face of new environmental challenges; and the
resulting evolutionary novelties are reinforced in successive generations through
epigenetic mechanisms, independently of natural selection.
Our proposal has held up well against subsequent research findings,
and is all the more relevant in view of the numerous molecular mechanisms
discovered in epigenetic inheritance (Ho, 2009a,b) that could transmit
developmental novelties to subsequent generations.
We have demonstrated how the nonlinear dynamics of living processes
predicts the major features of macroevolution such as ‘punctuated equilibria’
(long period of stasis interrupted by abrupt changes); large changes from small
critical disturbances, and discontinuous changes from continuously varying
parameters; and why macroevolution of form and function is decoupled from the
microevolution of gene sequences. We showed that the same (non-random)
developmental changes are repeatedly produced by specific environmental
stimuli. Furthermore, we demonstrated how general mathematical models can account
for all the developmental transformations experimentally produced, which can
make strong evolutionary predictions, and offer a natural taxonomy based on the
predicted transformations.
However, neither the epigenetic mechanisms nor the dynamics of
developmental processes are taken into account in the recent studies on
evolution and development.
The totality of research findings gives no support to the
neo-Darwinian theory of evolution by the natural selection of random genetic
mutations, nor to any theory ascribing putative differences in human attributes
to genes. The overwhelming determinants of health and behaviour are social and
environmental. Heredity is not in the genes, it is distributed over the entire
web of nested organism-environment interrelationships extending from the social
and ecological to the genetic and epigenetic. Consequently, there is no
separation between development and evolution, and the organism actively
participates in shaping its own development as well as the evolutionary future
of the entire ecological community of which it is part.
| |
|
