Allozyme variation in populations of Cepaea nemoralis from Northern Spain

Abstract

Allozyme frequencies at eleven gene loci have been tested electrophoretically in 46 populations of the land snail Cepaea nemoralis from the North of Spain. There is some geographic differentiation for molecular polymorphism which coincides to some small extent with the two main climatic regions in the Iberian peninsula, “green” and “brown” Iberia. However, there are no significant correlations between gene frequencies and climatic parameters. At least, part of this geographic change may have emerged through genetic drift, with a counterbalanced action of drift and climatic selection associated with a restricted gene flow, to promote a different genetic structure of C. nemoralis populations in each climatic region. © 1989, The Genetical Society of Great Britain.