Geographic Variation in Genic and Morphological Characters in Peromyscus californicus

Abstract

Allelic variation was examined at 31 structural gene loci in 13 populations of Peromyscus californicus. Northern populations of P. californicus differ sharply from southern populations in allelic frequency at four of 17 polymorphic loci. Heterozygosity levels are high in the zone of contact between the northern and southern units, and also high in southern populations. A multivariate analysis of variation in morphological characters in 17 populations distinguishes two groups of populations similar to the grouping based on variation at electrophoretic loci. Northern populations are assigned to the subspecies Peromyscus californicus californicus; southern populations are assigned to the subspecies Peromyscus californicus insignis. The role of changes in the topography of coastal California and changing vegetation and climatic patterns in contributing to differentiation within this species is considered.