2CHANGE – To Change or not to Change? The genetic basis and evolution of seasonal coat colour polymorphism

Seasonal coat colour change from a brown summer to a white winter coat is a pervasive trait across mammals in habitats periodically covered with snow. This remarkable adaptation has strong impacts in fitness, by allowing the maintenance of crypsis year-round. Winter colour is often polymorphic, with populations in areas with lower persistence of snow maintaining the summer coat in winter. It is therefore a phenotype strongly shaped by selection, with important consequences for future species survival, because climate change will tend to reduce snow-cover and disrupt crypsis in winter white individuals. We will study the genetic basis of seasonal coat colour polymorphism in three different species of weasels (Mustela spp.) and address evolution and population genomics of this colour polymorphism, which may have evolved independently across species.