Snow skinks are viviparous lizards from Tasmania. An interesting feature of our study species, Niveoscincus ocellatus, is that it occurs from sea level to high altitude. The latter conditions are not very suitable for ectotherms, but snow skinks persist, partly thanks to behavioural shifts in thermoregulation.
Together with Erik Wapstra and Ido Pen we demonstrated adaptive divergence in sex determination between populations in different climates. Specifically, sex determination in lowland populations, but not in highland populations, is temperature-dependent. This is adaptive because when the activity season is long, daughters benefit more from being born early than sons. This difference in fitness disappears in the shorter activity season at high altitudes, making sex ratios evolved to the usual 50:50.