The search for knowledge is in our genes. It was put there by our distant ancestors who spread across the world, and it's never going to be quenched.

Biodiversity is the totality of all inherited variation in the life forms of Earth, of which we are one species. We study and save it to our great benefit. We ignore and degrade it to our great peril.

No species ... possesses a purpose beyond the imperatives created by genetic history ... The human mind is a device for survival and reproduction, and reason is just one of its various techniques.

Humanity, in the desperate attempt to fit 8 billion or more people on the planet and give them a higher standard of living, is at risk of pushing the rest of life off the globe.

Individual versus group selection results in a mix of altruism and selfishness, of virtue and sin, among the members of a society. If one colony member devotes its life to service over marriage, the individual is of benefit to the society, even though it does not have personal offspring. A soldier going into battle will benefit his country, but he runs a higher risk of death than one who does not. An altruist benefits the group, but a layabout or coward who saves his own energy and reduces his bodily risk passes the resulting social cost to others.

Evolution by natural selection is not an idle hypothesis. The genetic variation on which selection acts is well understood in principle all the way down to the molecular level.

The naturalist is a civilized hunter. He goes alone into the field or woodland and closes his mind to everything but that time and place, so that life around him presses in on all the senses and small details grow in significance. He begins the scanning search for which cognition was engineered. His mind becomes unfocused, it focuses on everything, no longer directed toward any ordinary task or social pleasantry.