Rate of evolution

The rate of evolution is a variable of considerable interest in evolutionary biology. It concerns the limits of adaptation to natural environments as well as the limits of artificial selection.

Humans have created a wide range of new species, and varieties within those species, of both domesticated animals and plants. This has been achieved in a very short geological period of time, spanning only a few tens of thousands of years, and sometimes less. Maize, Zea mays, for instance, is estimated to have been created in what is now known as Mexico in only a few thousand years, starting between about 7 000 and 12 000 years ago, from still uncertain origins. In the light of this extraordinarily rapid rate of evolution, through (prehistoric) artificial selection, George C. Williams and others, have remarked the following: