This tutorial has introduced three methods of measuring rates of evolution:

1. For single characters that show continuous variation, we can measure the metrical rate of change and express it in darwins.

2. For characters with discrete states, each state is given an arbitrary score and we can measure the rate of change of the score.

3. A cruder measure is provided by the duration of species in the fossil record, because taxonomists will recognize a higher turnover of species in groups that evolve rapidly.

All three methods have their particular uses and applications and paleobiologists have used measures of evolutionary rates to study a number of general questions.