Fig. 4From: Drift, selection, or migration? Processes affecting genetic differentiation and variation along a latitudinal gradient in an amphibianMHC genetic variation (blue circles (southern cluster). and green circles (northern cluster). Microsatellite variation is given in pink tringles (southern cluster) and orange triangles (northern cluster). The linear regression is represented by a black line. a) HEÂ =Â Expected heterozygosity and b) ARÂ =Â allelic richnessBack to article page