The effect of historical legacy on adaptation: do closely related species respond to the environment in the same way?

The many documented examples of parallel and convergent evolution in similar environments are strong evidence for the role of natural selection in the evolution of trait variation. However, species may respond to selection in different ways; idiosyncrasies of their evolutionary history may affect how different species respond to the same selective pressure. To determine whether evolutionary history affects trait-environment associations in a recently diverged lineage, we investigated within-species trait-environment associations in the white proteas, a closely related monophyletic group. We first used MANOVAs to determine the relative importance of shared response to selection, evolutionary history, and unique responses to selection on trait variation. We found that on average, similar associations to the environment across species explained trait variation, but that the species had different mean trait values. We also detected species-specific associations of traits to the environmenta...