BIOL 101 Lecture Notes - Lecture 11: Epistasis, Pleiotropy, C. H. Waddington
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Def: genotypes that produce different phenotypes in response to environmental conditions (environmental sensitivity affecting genotypes) Plasticity genes: regulatory loci (genes) that directly respond to a specific environmental stimulus by triggering a specific series of actions. Some aspect of the phenotype in a single species and single population. James mark baldwin -- individuals differ not only in their phenotypic attributes, but but in the way those attributes are altered by changing environmental conditions. Those organisms more adaptable to new conditions => more offspring. S: evolution works by altering the developmental systems of organisms, thus changing the norm of reaction to cope with and anticipate environmental stimuli. Reaction norms and phenotypic plasticity were not considered to be particularly important overall in evolution In fact, plasticity was generally thought to help organisms avoid selection and thus it would prevent evolution. Began with the introduction of the concept of the reaction norm (called phenotypic curves) by richard woltereck (1909)
