Which of these units is used to measure the rate of evolutionary change?

The darwin (d) is a unit of evolutionary change, defined by J.B.S. Haldane in 1949. One darwin is defined to be an e-fold (about 2.718) change in a trait over one million years. Haldane named the unit after Charles Darwin.

Rates of evolution change vary widely, among characteristics, and among species. Evolutionary rate of change can be estimated by examining fossils and species that are related to each other. The rate of change is governed partly by the life span of the species under examination; species whose individuals have short life spans are generally capable of changing more quickly than those that have a longer life span and reproduce less often. Yet, even short-lived species such as bacteria, which have generation times measured in minutes, may not manifest noticeable evolutionary changes in a humans lifetime.