We are justified in calling all species of bipedal ape "human." ...the adaptation of bipedalism was so loaded with evolutionary potential—freeing the… - Richard Leakey

The quality that accompanies the emergence of learning in the evolution of higher animals, namely intelligence, is surprisingly difficult to define.

The neurobiologist Harry Jerison has made a long study of the trajectory of brain evolution since the advent of life on dry land. ...the origin of new faunal groups is usually accompanied by a jump in the relative size of the brain, known as encephalization. ...the first archaic mammals... were equipped with brains four to five times bigger than the average reptilian brain... primates are twice as encephalized as the average mammal. Within primates, the apes... are some twice the average size. And humans are three times as encephalized as the average ape.

Protecting elephants and conserving natural ecosystems remain my personal priorities. But I am not so sure this would be so were I ill, hungry, and living in dispair. ...We must somehow find a way to provide for our own species if we are also to preserve others.