Area effect in south western European green frogs (Amphibia, Ranidae)

Abstract

Enzyme polymorphism in SW European green frogs (Rana esculenta Complex) show concordant patterns of very high differentiation between populations. Demes sampled in N Italy are all identifiable by at least one diagnostic locus, while those from Spain and S. France (Rana perezi), differ from the latter over five such loci. No single individual was found to be heterozygous for all non‐mono‐morphic loci. This pattern of variation is correlated to interdemic morphological differentiation and denotes the accumulation of major genetic differences resulting in local coadapted gene complexes. It is therefore interpretable in terms of area effect and stasipatric model of evolution.

The genetic structure of these SW European populations of green frogs is not compatible with the hybridogenetic model.

Key words:

• ‘Rana esculenta’ Complex
• high interpopulation genetic divergence
• area effect
• electrophoreses