"Evolution thus is merely contingent on certain processes articulated by Darwin: variation and selection"

Ernst Mayr's quote recommends that advancement is dependent on the processes of variation and selection, as articulated by Charles Darwin. Variation is the process by which organisms establish various qualities, while choice is the procedure by which specific characteristics are preferred over others. Together, these two procedures are responsible for the evolution of types in time. Mayr's quote indicates that evolution is not predetermined, however rather is contingent on the incident of these two processes. This means that advancement is not a direct process, but rather is formed by the environment and the organisms within it. As such, the result of evolution is unpredictable and can be affected by a variety of factors. Mayr's quote highlights the importance of variation and choice in the evolutionary process, and highlights the role of possibility in the advancement of species.