The rate of evolutionary change is the speed at which new species arise. It is a long process that is not observable within a human lifetime. Evolutionary change can only be observed by examining fossils and species that are related to each other. The rate of change is governed by the generational turnover of the species under examination, fast lived species are capable of changing more quickly than those that have a long life span and reproduce less often.

Even fast-lived species such as bacteria, some of which have generation times which can be measured in minutes, cannot be said to have shown evolutionary change in the time that humans have been observing them. Some viruses such as HIV are often reported as being present in new forms, but they are still recognizable as HIV. Over sufficient time, there will be enough...