Resumen

Species that contain populations with different reproductive modes offer excellent opportunities to study the transition between such strategies.Salamandra salamandra(Linnaeus, 1758) is one of two species within theSalamandra–Lyciasalamandraclade which displays two reproductivemodes simultaneously. Along theS. salamandradistribution, the common reproductive mode is ovoviviparity although the species also hasviviparous populations in the northern Iberian Peninsula. The occurrence of viviparity has recently been reported in two small offshore islandpopulations on the Atlantic coast (NW Iberia), which originated after the last glacial period (8000–9000 years ago). In this paper, we analysedovoviviparous, hybrid and viviparous populations (inland and mainland) from 17 localities across the northern Iberian Peninsula using twomitochondrial markers (CytbandCOI,c. 1100 bp). Phylogenetic and phylogeographic analyses highly support that viviparity arose as anevolutionary novelty in theS. salamandraisland populations and that viviparous populations are therefore not monophyletic. The recentinsularity of Atlantic island populations leads us to conclude that the transition from ovoviviparity to viviparity can happen in a very short-timespan. Additionally, to determine the likely source of this evolutionary transition, we discuss how ecological pressures could have an effect on themaintenance of the ovoviviparous reproductive mode. Hence, taking into account the results of this study, we propose the consideration of theisland populations as an evolutionary unit for conservation purposes.