chapter  1
Evolutionary Theory
Pages 32

The modern theory of evolution owes its existence to two remarkable 19th-century scientists, Charles Darwin and Gregor Mendel. It is widely recognized as one of the greatest accomplishments of the human mind, with implications that have still yet to be fully grasped. After 150 years and many challenges, Darwin’s theory of evolution by natural selection has revolutionized our thinking about the natural world and the place of humans in it. It has restructured and energized the biological and behavioral sciences, and its impact on psychology has never been stronger than it is today. Its relation to the many diverse and expanding fields of biology was summed up succinctly by Dobzhansky (1973, p. 125): “Nothing in biology makes sense except in the light of evolutionary theory.”