Abstract
AbstractBiological invasions offer particularly convenient situations to study phenotypic evolution in natural populations. In particular, the comparison of derived, invasive populations with ancestral extant populations allows to investigate the relative impact of neutral demographic events, genetic constraints and selection on the evolution of phenotypes. In this paper, focusing on the worldwide invasion ofDrosophila suzukii(Matsumara, 1931), we investigate how phenotypic divergence among populations is constrained by the genetic correlations summarized in the genetic covariance matrixGand howGitself evolves throughout periods of drift and selection. Leveraging invasion history resolved by population genetics approaches, we compared wing shapeGmatrices among ancestral native and derived invasive populations, contrasting patterns of quantitative divergence among populations to neutral expectations. Our results show moderate yet significant quantitative genetic differentiation of wing shape amongD. suzukiipopulations and a relative stability in the structure ofG, presenting a roughly spherical shape but slightly different volumes. These characteristics likely reflect the demographic history of populations and suggest a low level of genetic constraint on adaptive evolution. The divergence among populations was greater than expected under a purely neutral model of evolution, compatible with an effect of selection on wing shape. Overall, our study suggests that selection, drift but not constraints affected the early stages of wing shape evolution duringD. suzukiiinvasion.
Publisher
Cold Spring Harbor Laboratory