Adaptation: by giant leaps or many tiny steps?

Abstract

Despite more than a century of research, we still lack a general understanding of the genetic basis of adaptation. We argue that reframing this question around the genetic and ecological properties of the traits under selection may chart a way forward. In this Comment, the authors argue that understanding the genetic basis of adaptation requires considering the genetic architecture and ecological properties of traits under selection. They propose a framework that predicts when evolution proceeds by many small changes or few large-effect variants, and when its genetic basis should be predictable across populations and species.