QST FST As a signature of canalization


Correspondence: Sylvain Delzon, Fax: 33 (0)5 40 00 36 57; E-mail: sylvain.delzon@u-bordeaux1.fr


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 (FST) with quantitative genetic variation (QST). Each of the three possible outcomes of comparisons of QST and FST (QST FST, QST FST, QST FST) is associated with an inference (diversifying selection, genetic drift, uniform selection, respectively). However, published empirical and theoretical studies have focused on the QST FST outcome. We believe that this reflects the absence of a straightforward biological interpretation of the QST < FST 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.