The greatest of all the accomplishments of 20th century science has been the discovery of human ignorance

Animals have genes for altruism, and those genes have been selected in the evolution of many creatures because of the advantage they confer for the continuing survival of the species.

The uniformity of the earth’s life, more astonishing than its diversity, is accountable by the high probability that we derived, originally, from some single cell, fertilized in a bolt of lightning as the earth cooled....

All of today’s DNA, strung through all the cells of the earth, is simply an extension and elaboration of [the] first molecule.

Statistically, the probability of any one of us being here is so small that the mere fact of our existence should keep us all in a state of contented dazzlement.

…the life of the planet began the long, slow process of modulating and regulating the physical conditions of the planet. The oxygen in today’s atmosphere is almost entirely the result of photosynthetic living, which had...

I am a member of a fragile species, still new to the earth, the youngest creatures of any scale, here only a few moments as evolutionary time is measured, a juvenile species, a child of...

The greatest single achievement of nature to date was surely the invention of the molecule DNA.

As evolutionary time is measured, we have only just turned up and have hardly had time to catch breath, still marveling at our thumbs, still learning to use the brand-new gift of language. Being so...

We are, perhaps uniquely among the earth’s creatures, the worrying animal. We worry away our lives, fearing the future, discontent with the present, unable to take the idea of dying, unable to sit still.

Worrying is the most natural and spontaneous of all human functions. It is time to acknowledge this, perhaps even to learn to do it better.

It is in our genes to understand the universe if we can, to keep trying even if we cannot, and to be enchanted by the act of learning all the way.