We are here because one odd group of fishes had a peculiar fin anatomy that could transform into legs for terrestrial creatures; because the earth never froze entirely during an ice age; because a small and tenuous species, arising in Africa a quarter of a million years ago, has managed, so far, to survive by hook and by crook. We may yearn for a ‘higher answer’– but none exists

We pass through this world but once.

I was lucky to wander into evolutionary theory, one of the most exciting and important of all scientific fields. I had never heard of it when I started at a rather tender age; I was simply awed by dinosaurs. I thought paleontologists spent their lives digging up bones and putting them together, never venturing beyond the momentous issue of what connects to what. Then I discovered evolutionary theory. Ever since then, the duality of natural history-richness in particularities and potential union in underlying explanation-has propelled me.

What you see is that the most outstanding feature of life's history is a constant domination by bacteria.

The history of life is a tale of decimation and later stabilization of few surviving anatomies, not a story of steady expansion and progress.

Theory and fact are equally strong and utterly interdependent; one has no meaning without the other. We need theory to organize and interpret facts, even to know what we can or might observe. And we need facts to validate theories and give them substance.

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.