The commas are the most useful and usable of all the stops. It is highly important to put them in place as you go along. If you try to come back after doing a paragraph and stick them in the various spots that tempt you you will discover that they tend to swarm like minnows into sorts of crevices whose existence you hadn't realized and before you know it the whole long sentence becomes immobilized and lashed up squirming in commas. Better to use them sparingly, and with affection, precisely when the need for each one arises, nicely, by itself.

Worrying is the most natural and spontaneous of all human functions.

Well, biology today as I see it has an amiable look - quite different from the 19th-century view that the whole arrangement of nature is hostile, 'red in tooth and claw.' That came about because people misread Darwin's 'survival of the fittest.'

I can say, if I like, that social insects behave like the working parts of an immense central nervous system: the termite colony is an enormous brain on millions of legs; the individual termite is a mobile neurone.

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 gift of language is the single human trait that marks us all genetically, setting us apart from the rest of life.

Survival, in the cool economics of biology, means simply the persistence of one's own genes in the generations to follow.