An unfortunate outgrowth of the modern revolution in genetics is the widespread belief that the genes of an individual organism determine its appearance, physiology and behavior. The genome does not, of course, completely determine how an organism is constructed: The environment is an essential partner.
Nowhere is this point more clearly illustrated than by the principle of developmental plasticity—the tendency for genetically identical organisms to differ in response to various environmental stimuli, or for individuals to vary over time as the result of changing conditions in their surroundings.
In Developmental Plasticity and Evolution, Mary Jane West-Eberhard, an evolutionary biologist at the Smithsonian Tropical Research Institute and a member of the National Academy of Sciences, undertakes to explain how developmental plasticity fits within a genetic theory of evolution.
Read the full, original story: Putting Genes in Perspective