It's not good enough to give it tender, loving care, to supply it with breakfast foods, to buy it expensive educations. Those things don't mean anything unless this generation has a future. And we're not sure that it does.

Science goes from question to question; big questions, and little, tentative answers. The questions as they age grow ever broader, the answers are seen to be more limited.

The thought that we're in competition with Russians or with Chinese is all a mistake, and trivial. We are one species, with a world to win.

I tell my students, with a feeling of pride that I hope they will share, that the carbon, nitrogen, and oxygen that make up ninety-nine per cent of our living substance were cooked in the deep interiors of earlier generations of dying stars. Gathered up from the ends of the universe, over billions of years, eventually they came to form, in part, the substance of our sun, its planets, and ourselves. Three billion years ago, life arose upon the earth. It is the only life in the solar system.

Faced with a new mutation in an organism, or a fundamental change in its living conditions, the biologist is frequently in no position whatever to predict its future prospects. He has to wait and see. For instance, the hairy mammoth seems to have been an admirable animal, intelligent and well-accoutered. Now that it is extinct, we try to understand why it failed. I doubt that any biologist thinks he could have predicted that failure. Fitness and survival are by nature estimates of past performance.

Every creature alive on the earth today represents an unbroken line of life that stretches back to the first primitive organism to appear on this planet; and that is about three billion years.

I tell my students to try early in life to find an unattainable objective.