“As our numbers increase, so space for other animals and plants decreases. Our skills and technological ingenuity seem to know no bounds. Having ventured to every corner of our planet, we are now beginning to look beyond it. We are conducting experiments to find out how to grow food to sustain ourselves should we manage to extend the territory of our species to Mars. Men impressed their footprints on the moon a mere three and a half million years after the first of them to walk upright left theirs across a field of volcanic ash in Africa. This is a mere blink in the eye of evolution. In that short time we, alone among all animals, have discovered how to exploit our environment to produce more and more food to sustain our unparalleled numbers. In so doing we have denied the earth to other species to such an extent that many have been driven into extinction and many more are now trembling on the brink. Perhaps the time has come, when we should put our aspirations into reverse. Perhaps now, instead of controlling the environment for the benefit of our population, we should find ways of controlling our population to ensure the survival of our gravely threatened environment.”