All interesting issues in natural history are questions of relative frequency, not single examples. Everything happens once amidst the richness of nature. But when an unanticipated phenomenon occurs again and again—finally turning into an expectation—then theories are overturned.

Natural selection may lead to benefits for species, but these `higher' advantages can only arise as sequelae, or side consequences, of natural selection's causal mechanism: differential reproductive success of individuals.

Sigmund Freud often remarked that great revolutions in the history of science have but one common, and ironic, feature: they knock human arrogance off one pedestal after another of our previous conviction about our own self-importance.

Fundamentalism is rigorously and systematically used to indoctrinate and subjugate young minds. It is a contraceptive designed to prevent intellectual fertilization.

Humans are not the end result of predictable evolutionary progress, but rather a fortuitous cosmic afterthought, a tiny little twig on the enormously arborescent bush of life, which if replanted from seed, would almost surely not grow this twig again.

The basic formulation, or bare-bones mechanics, of natural selection is a disarmingly simple argument, based on three undeniable facts (overproduction of offspring, variation, and heritability) and one syllogistic inference (natural selection, or the claim that organisms enjoying differential reproductive success will, on average, be those variants that are fortuitously better adapted to changing local environments, and that these variants will then pass their favored traits to offspring by inheritance).

Change is more often a rapid transition between two stable states than a continuous transformation at slow and steady rates. . . .Change occurs in large leaps following a slow accumulation of stress that a system resists until it reaches the breaking point. Heat water, and it eventually boils. Oppress the workers more and more and bring on the revolution.