What would a predator-free world look like?

Conservation is the name of the game in most ecological thinking - but in the eyes of some environmental philosophers, conservation is a backward-looking concept. What if, instead of looking to conserve nature, we tried to recreate and improve it via biotechnology? This year's Alan Saunders Lecture explores such futuristic interventions as reviving extinct species, turning carnivores into herbivores and genetically engineering less resource-intensive humans.