How all life on Earth was almost wiped out – five times

Thos weekend,  I watched episode 2 of the fascinating new American television series “Cosmos: A Spacetime Odyssey”.

This episode concentrated on evolution and referred to the five great extinctions when substantial proportions of life on the planet were made extinct.

The best known one – the Cretaceous-Tertiary mass extinction – wiped out the dinosaurs, but the most severe – yhe Permian mass extinction (nicknamed The Great Dying) – eliminated around 96% of all life forms. We are descended from the 4% that survived.

You can learn more about these great extinctions here.