...Homo sapiens doesn't seem able to cut himself off at the supply end. He's one of the few species that doesn't limit reproduction in the face of dwindling resources. In other words - and up to a point, of course - the less we eat, the more we fuck.' 'How do you account for that?' said Jimmy. 'Imagination,' said Crake, 'Men can imagine their own deaths, they can see them coming, and the mere thought of impending death acts like an aphrodisiac. A dog or a rabbit doesn't behave like that. Take birds - in a lean season they cut down on the eggs, or they don't mate at all. They put their energy into staying alive themselves until times get better. But human beings hope they can stick their souls into someone else, some new version of themselves, and live on forever.' 'As a species we're doomed by hope then?' 'You could call it hope. That, or desperation.' 'But we're doomed without hope, as well,' said Jimmy. 'Only as individuals,' said Crake cheerfully. 'Well, it sucks.' 'Jimmy, grow up.' Crake wasn't the first person who ever said that to Jimmy.