All organisms vary, and it's just folk knowledge. You just have to look around a room of people, and everybody knows that it's true. Darwin didn't know the mechanism of heredity, but you don't have to. You just need to know the fact of it.

Taxonomy (the science of classification) is often undervalued as a glorified form of filing-with each species in its folder, like a stamp in its prescribed place in an album; but taxonomy is a fundamental and dynamic science, dedicated to exploring the causes of relationships and similarities among organisms. Classifications are theories about the basis of natural order, not dull catalogues compiled only to avoid chaos.

The center of human nature is rooted in ten thousand ordinary acts of kindness that define our days.

The proof of evolution lies in those adaptations that arise from improbable foundations.

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.

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.

No one-liner can ever be optimal.