Extinction!
Liam Neeson narrates this film, considering the process of extinction and its implications for evolutionary theory. Five mass extinctions have occurred during the life of the earth, but what form will the next one take? University of Washington paleogeologist Peter D Ward explains that extinction is normal and is happening all the time. At least 95 per cent of all species that have ever lived are now extinct. A mass extinction at the end of the Permian period saw the emergence of two important groups of land animals – dinosaurs and small mammal-like reptiles. After millions of years another mass extinction occurred at the end of the Cretaceous period, wiping out the dinosaurs but sparing the smaller mammals. Freed from having to compete with the dinosaurs, mammals spread out to all parts of the world, adapting and diversifying. Then, around 5 million years ago, the first human precursors emerged in Africa – mammals that would play an unprecedented role in evolution's future. But where are we going from here? Wildlife Conservation Society scientist Alan Rabinowitz studies the ecosystem of a remote rainforest in Thailand and asks what role humans are playing in the extinction process. Could we unwittingly be the catalyst that will cause the next mass extinction? And what does evolutionary theory predict for the world we will leave to our descendants?