Evolution is the scientific concept that life gradually adapts to changes in the environment through a process of mutation, natural selection and the struggle for survival. This idea was first described by Charles Darwin in 1859 and is now accepted as the most fundamental principle in all life sciences. Although not explicitly mentioned in the Tipitaka, the idea of evolution is remarkably consistent with the Buddha’s teachings about the craving to live (bhava tanha) and that everything changes (anicca). In the Agganna Sutta the Buddha says that after the earth came into being it was completely covered with water, that the first life-forms floated on the surface where they fed on nutrition and that they gradually changed from simple to complex over a vast period of time (D.III, 84-88). To the theistic religions which teach that humans are a special creation by God, the idea that humans could have evolved from lower animals is deeply offensive.
"An understanding and acceptance of the theory of evolution is important because without that acceptance there is a perception of a great separation between humans and animals which simply is not true."
Buddhists have always believed that animals are worthy of love and respect, that humans can even sometimes be reborn as animals or animals as humans and therefore they are quite comfortable with the concept of evolution.