History, selection, drift, and gene flow: complex differentiation in checkerspot butterflies

Abstract

The genetic structure of the checkerspot butterfly, Euphydryas editha, was investigated using gel electrophoresis at 19 loci in each of 41 populations from throughout the range of the species. With two exceptions the populations were found to be very similar genetically, despite great differences in morphology and ecology. The low level of population differentiation was attributed to a combination of a historically more continuous range, parallel selection, and gene flow.