Over the following 70 or 80 million years the rate of evolution accelerated by an order of magnitude , as defined in terms of the extinction and origination rate of species . The diversity of life began to resemble that of today . Over the following 70 or 80 million years the rate of evolution accelerated by an order of magnitude ( as defined in terms of the extinction and origination rate of species ) and the diversity of life began to resemble todayâ s.