A NEW MALE human being entered the universe a year ago, with one-eighth of his genetic material identical to my mother’s and one-eighth identical to my father’s. Those millions of delicate fragments of code, assembled around a hundred years ago, were duplicated perfectly, then duplicated perfectly again and finally copied into a microscopic drop of cell matter, to begin yet another voyage through space and time and consciousness with its own unique human identity. It is a mystery, to me. But tens of thousands of mysteries like that happen every day.

Within a hundred years the billions of molecules that make up this lively, cheerful, noisy creature will disperse and never reassemble again: except for that tiny fraction that may end up in another human’s genetic make-up to travel down the centuries, mixing with other genetic material and incarnating again and again.