The two different rates of evolution, gradualism and punctuated equilibrium, show that evolution has proceeded at different rates for different organisms at different times over the long history of life on Earth. Darwin suggested that evolution needed to be slow and steady, but numerous examples in the fossil records indicate that the pattern of slow, steady change does not always hold. Groups of organisms that survive mass extinctions evolve rapidly in the several million years after the extinction to fill the many ecological niches that have been left. These different rates of evolution are important as it again, explains that changes in life are not fixed, and is random (whether in the rate, or how it occurs). Also, the rate of evolution can help humans infer what happened during specific time periods. For example, if rapid changer has occurred during a specific time period, we can infer that something drastic must have happened in that specific environment during that specific time period for rapid change to occur. Reversely, if a species has gradually evolved during a specific time period, it is quite safe to assume that nothing drastic has happened to the environment during that time.

*NOTE: We understand that there are some spelling mistakes ("poulations" and "overtime") in the graph above. However, our group was quite impressed by the graph and the individual who made the graph is currently on a vacation, so we cannot fix the spelling mistakes. Just thought you should know.