Peaceful coexistence
"whenever we find rather similar animals living together in the wild, we do not hink of competition by tooth and claw, we ask ourselves, instead, how competition is avoided. When we find many animals apparently sharing a food supply, we do not talk of struggles for survival; we watch to see by what trick the animals manage to be peaceful in their coexistence.
Peaceful coexistence, not struggle, is the rule in our Darwinian world. A perfectly fashioned individual of a Darwinian species is programmed for a specialised life to be spent for the most part safe from competition with neighbours of other kinds. Natural selection is harsh only to the deviant aggressor who seeks to poach on the niche of another. The peaceful coexistence between species, which results from evolution by natural selection, has to be understood as an important fact in the workings of the great ecosystems around us. It is also, surely, one of the most eartening of the lessons of biology. "