Q_ST < F_ST As a signature of canalization

Abstract

A key aim of evolutionary biology – inferring the action of natural selection on wild species – can be achieved by comparing neutral genetic differentiation between populations (F_ST) with quantitative genetic variation (Q_ST). Each of the three possible outcomes of comparisons of Q_ST and F_ST (Q_ST > F_ST, Q_ST = F_ST, Q_ST < F_ST) is associated with an inference (diversifying selection, genetic drift, uniform selection, respectively). However, published empirical and theoretical studies have focused on the Q_ST > F_ST outcome. We believe that this reflects the absence of a straightforward biological interpretation of the Q_ST < F_ST pattern. We here report recent evidence of this neglected evolutionary pattern, provide guidelines to its interpretation as either a canalization phenomenon or a consequence of uniform selection and discuss the significant importance this issue will have for the area of evolutionary biology.