A global test of the cold‐climate hypothesis for the evolution of viviparity of squamate reptiles

摘要: AIM: The evolution of viviparity in squamate reptiles has attracted considerable scientific attention since the beginning last century. cold‐climate hypothesis posits that cold regions favor (and therefore incidence viviparous squamates is increased these regions) because females can use thermoregulatory behavior to shorten embryonic developmental time and reduce exposure embryos stressful temperatures. However, a rigorous global‐scale test impact on viability still absent. Recently developed biophysical models climate databases enable us conduct mechanistic this hypothesis. LOCATION: Global. TIME PERIOD: Summer. MAJOR TAXA STUDIED: Squamata. METHODS: We integrated global data, model, functions quantify effects temperature embryo time, viability, energy consumption oviparous versus embryos. To examine accuracy our predictions, we calculated percentage were each region assessed gravid females, latitude elevation as predictors for reptiles. RESULTS: Compared with embryos, develop faster regions, experience similar viability. Across most latitudes elevations, total energetic cost development lower than Cold contain higher proportion species do hot regions. By comparing distribution pattern development, found shortened provided strongest benefit viviparity. MAIN CONCLUSIONS: Our model based comparison generally supports Moreover, climates appears beneficial primarily by shortening time.