In a joint publication with Alfred Russel Wallace, he introduced his scientific theory that this branching pattern of evolution resulted from a process that he called natural selection, in which the struggle for existence has a similar effect to the artificial selection involved in selective breeding.
Nunha publicación conxunta con Alfred Russel Wallace, introduciu a teoría de que ese fenómeno de diversificación é o resultado do que denominaron selección natural; un proceso no que a competición por persistir ten a mesma resultante que teñen os cruzamentos selectivos na selección artificial.