Evolution of reproductive seasonality in bears

摘要: 1. Of the eight species of Ursidae, six are currently at risk extinction and remainder face significant risks to their future survival. One greatest threats bears is human-imposed environmental alteration (e.g. global warming, chemical pollutants, deforestation). An examination reproductive biology phylogeny Ursidae reveals seasonality as a probable adaptation adverse conditions. 2. Seven extant exhibit distinct mating birth seasons, with most ancient evolving facultative an increasingly seasonal climate Pliocene. The evolved during Pleistocene glaciations, under conditions severe food restriction. Under these conditions, obligate mode emerged persists present. 3. Knowledge natural history reproduction in ursids how it response climatic change provides context for understanding ramifications current on important species.