The Great Dying

It is estimated that 99 per cent of species have become extinct and there have been times when life's hold on Earth has been so precarious it seems it hangs on by a thread.

This series focuses on the survivors - the old-timers - whose biographies stretch back millions of years and who show how it is possible to survive a mass extinction event which wipes out nearly all of its neighbours. The Natural History Museum's Professor Richard Fortey discovers what allows the very few to carry on going - perhaps not for ever, but certainly far beyond the life expectancy of normal species. What makes a survivor when all around drop like flies?

In this episode Professor Fortey focuses on a series of cataclysms over a million-year period, 250 million years ago.