Angular homeostasis. V: Some issues in genetics, ontogeny, and evolution

We discuss a provisional model that deals with aspects of normal control of the direction in which cells grow; hence, the organization of structure. The interacting issues of genetics, ontogeny, and phylogeny in relationship to normal development and its defects are addressed. Our main goal is to define a model with a small and sufficient set of conditions that would make it possible to undertake statistically efficient genetic studies of certain congenital defects. But to do so in plausible and heuristic terms, one must address two classical questions: 1) How is the genome translated (or sometimes mistranslated) into a phenotype that is clinically conspicuous and that can be the object of genetic selection, and hence of evolution? 2) Granted that evolution of species occurs in small, rare steps, what is the path that calls for the smallest number of mutations through which ontogenesis could have developed, the intermediate stages being conserved because of actual phenotypic advantage?