The genotype-phenotype map structure and its role for evolvability
Résumé
The potential for evolutionary change is deeply anchored in the kind and amount of heritable phenotypic variation that organisms can produce, and thus in the way that genetic predispositions translate into the phenotype. That translation is the genotype-phenotype (GP) map. Here, we first explain the two common conceptualizations of GP map: the global correspondence map and the local mechanistic map, and how they relate to each other. We focus on the structural aspects of the GP mapping, as summarized in the notions of pleiotropy and epistasis, and argue that their effect on evolvability is not captured sufficiently in the current theory. One way to approach this problem is to address mechanistic, causal mapping explicitly and explore systematically the variational properties of various well-known biochemical or regulatory processes. This may allow us not only to better account for the effects of pleiotropy and epistasis, but to potentially complement these summarizing concepts themselves with notions that better capture the underlying mechanisms-thus adding to the mechanistic aspect to the global GP map.