The genotype-phenotype link

Abstract
The basic knowledge which has opened for the new discipline of functional genomics stems from one hundred years of debates and experimentation among devoted geneticists, who tried to understand the processing of gene expression into phenotypic design without the molecular tools that are now available. Here I recapitulate some old and some newer results from this research, which illustrate the ways in which changes in genetic variation can be induced, how it can be kept latent or, when needed, be expressed in the phenotype.