People are storytelling creatures. We like stories that go somewhere, and therefore we like trends - because trends are things that either get better or get worse, so we can either rejoice or lament. But we mistakenly depict many things as trends moving in some direction. We take the "full house" of variation in a system and try to represent it as a single number, when in fact what we should be doing is studying the variation as it expands and contracts. If you look at the history of the variation in all its complexity, then you see there's no trend.

But if we laugh with derision, we will never understand. Human intellectual capacity has not altered for thousands of years so far as we can tell. If intelligent people invested intense energy in issues that now seem foolish to us, then the failure lies in our understanding of their world, not in their distorted perceptions.

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.

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.

The world is too complex for subsumption under any general theory of change.

History employs evolution to structure biological events in time.

Einstein's theory of gravitation replaced Newton's, but apples did not suspend themselves in mid-air, pending the outcome. And humans evolved from apelike ancestors whether they did so by Darwin's proposed mechanism or by some other yet to be discovered.