How often do Extinction Level Events occur?
It has been suggested that there is a cycle of extinctions, with a mass extinction occurring every 26 to 30 million years. It is difficult to date fossils accurately enough to produce a reliable result, but most studies of this hypothetical cycle suggest that another mass extinction would be due in little more than 10 million years. There is abundant evidence that we are currently living in the middle of a man-made Holocene extinction event.
