A structuralist theory of evolution reconsidered.

The structuralist theory of evolution is reconsidered in the light of new discoveries. According to this theory, the evolutionary potentialities are in the genotype (a hierarchically ordered set of interacting elements) and manifest themselves in the course of morphogenesis in association with changes in the environment. It is demonstrated that this theory is in fact the development of a long philosophical tradition, in which Darwin and Neo-Darwinism did not participate. New discoveries in the field of molecular cytogenetics confirm the ideas of evolutionary potentiality and hierarchical genotypic ordering. It is demonstrated that gene regulation can manifest itself in association with instabilities of the morphogenetic field and the attainment of a new equilibrium; this change could be connected with changes in the environment, but has nothing to do with natural selection.