Zootoca vivipara as a model for testing evolutionary transition from oviparity to viviparity

The lizard Zootoca vivipara is one on the few example in Nature which shows, within the same species, populations with different reproductive modalities. Oviparous populations live in the southern part of its distributional range (the newly discovered Z.v.carniolica in Eastern-Italian Alps and Z.v.louislantzi in the Pyrenees), while viviparous subspecies (e.g. Z.v.vivipara and Z.v.sachalinensis) are widely distributed from British Isles and central France to Scandinavia and north-eastern Asia. This species is, therefore, particularly well suited for studying the evolutionary shift in reproductive mode.