Just How Close We May Be To Mass Extinction
It's a fact of life on Earth: every so often there are explosions of biodiversity, and new creatures evolve and flourish.
Then, from time to time, events lead to mass extinctions, wiping out many species in a short period of time. You'll hear people argue that we are now living through another mass extinction, but paleontologist Michael Hannah is not sure of that.
Comparisons to the fossil records he knows well don't support this as a mass extinction, but we may be close. Hannah writes up his thinking in the book Extinctions: Living and Dying in the Margin of Error.
He joins us to lay out just how close we are to a mass extinction.