Mechanisms for partial reproductive isolation in a Bombina hybrid zone in Romania

Differences between taxa which have devoloped in allopatry can contribute to reproductive isolation in the case of secondary contact. Hybrid zones are ideal study systems in which to investigate mechanisms for the inhibition of gene flow. This thesis describes a mosaic hybrid zone between the ecologically differentiated fire-bellied toads Bombina bombina and B. variegata. I show that the spatial arrangement of habitat, natural selection in tadpoles and phenotypic adaptation of the tadpoles to the favored habitat contribute essentially to reproduktive isolation.