Mammals are survivors-when dinosaurs went extinct, they survived. From lush jungles to deep oceans to sweltering deserts, mammals now dominate nearly every environment on Earth. But how did they do it? Take a trip back in time and discover how extreme changes in climate have pushed mammals to evolve new traits, including hooves, claws, tusks, big brains, and even blow holes. Join us as we explore our mammalian history, and maybe the past will hold the key to surviving in the future.