Unit 2: The Living World, Biodiversity

Some Animals Are More Equal than Others: Keystone Species and Trophic CascadesSome Animals Are More Equal than Others: Keystone Species and Trophic Cascades | This film tells the story of the ecologists who first documented the role of keystone species in ecosystem regulation.

This video from SciShow explores a major pattern of biodiversity--the latitudinal species gradient--and some of the hypotheses about evolutionary patterns leading to that gradient.