We pass through this world but once.

Science can't tell us what our life means ethically. It can't tell us what we are meant to do as moral creatures. But, insofar as science can understand what we're made of, and what we're related to, the Darwinian revolution completely revised our ideas about who we are and what we're related to and how long we've been here and why we're on this Earth.

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

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.

Human consciousness arose but a minute before midnight on the geological clock. Yet we mayflies try to bend an ancient world to our purposes, ignorant perhaps of the messages buried in its long history. Let us hope that we are still in the early morning of our April day.

The origin of Homo sapiens, as a tiny twig on an improbable branch of a contingent limb on a fortunate tree, lies well below the boundary.

The history of life is more adequately represented by a picture of 'punctuated equilibria' than by the notion of phyletic gradualism. The history of evolution is not one of stately unfolding, but a story of homeostatic equilibria, disturbed only 'rarely' (i.e. rather often in the fullness of time) by rapid and episodic events of speciation.