If everyone agreed to become vegetarian, leaving little or nothing for livestock, the present 1.4 billion hectares of arable land (3.5 billion acres) would support about 10 billion people.

I like what Abba Eban once said during the 1967 war. He said, "When all else fails, men turn to reason."

In the process of natural selection, then, any device that can insert a higher proportion of certain genes into subsequent generations will come to characterize the species.

The biological evolutionary perception of life and of human qualities is radically different from that of traditional religion, whether it's Southern Baptist or Islam or any religion that believes in a supernatural supervalance over humanity.

If insemination were the sole biological function of sex, it could be achieved far more economically in a few seconds of mounting and insertion. Indeed, the least social of mammals mate with scarcely more ceremony. The species that have evolved long-term bonds are also, by and large, the ones that rely on elaborate courtship rituals. . . . Love and sex do indeed go together.

We should preserve every scrap of biodiversity as priceless while we learn to use it and come to understand what it means to humanity.

The human juggernaut is permanently eroding Earth's ancient biosphere.