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.

It is not a simple life to be a single cell, although I have no right to say so, having been a single cell so long ago myself that I have no memory at all of that stage of my life.

Most things get better by themselves. Most things, in fact, are better by morning.

Doctors, dressed up in one professional costume or another, have been in busy practice since the earliest records of every culture on earth. It is hard to think of a more dependable or enduring occupation, harder still to imagine any future events leading to its extinction.

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

We owe our lives to the sun... How is it, then, that we feel no gratitude?

I agree that you might clone some people who would look amazingly like their parental cell donors, but the odds are that they'd be almost as different as you or me, and certainly more different than any of today's identical twins.