This study provides quantitative, model-based insight into the history of divergence and a longer-scale perspective on genetic exchange between the Carpathian and smooth newts. Despite introgression of nuclear genes, which followed period(s) of isolation, the species have maintained their distinctiveness, which suggests that gene flow has not affected genomic regions responsible for species-specific adaptations. The Carpathian newt hybridizes with two evolutionary lineages of the smooth newt, exchanging genes symmetrically with one of them but asymmetrically with the other. The results of our study highlight the importance of incorporating intraspecific genetic structure into the models investigating the history of divergence.

http://onlinelibrary.wiley.com/doi/10.1111/mec.13724/full