Georgy Semenov poster for Evolution 2017.pdf

Both production and evolutionary retention of a precise fit between an organism and its environment are commonly associated with narrowing and canalization of developmental variation. This should, in turn, limit the potential for subsequent adaptations. Yet, organisms are clearly built in such a way as to resolve this tension: intricate adaptations and exceptional diversification routinely coexist in the same traits. A potential resolution of this paradox is when natural selection on a fully grown structure does not modify its developmental elements directly, but instead rearranges and stabilizes them. What evolves under this scenario is a regulatory map that brings together developmental elements. Alternatively, evolution of ontogeny can proceed by accumulating changes in developmental elements themselves, with natural selection accomplishing matching of these changes with locally adaptive configurations. A test of these hypotheses requires direct study of what actually changes when ontogeny of a trait evolves. Recent colonization of Montana by house finches (Haemorhous mexicanus) that was associated with rapid evolution of their beak morphology, provides such opportunity. Here we aim to examine the extent to which extensive population divergence of adult beak morphology corresponded to population divergence in ontogenetic trajectories.