“THE path is clear, but will we take it?” asked a recentNew Scientist cover on how to boost the world’s harvest to alleviate the global food crisis (14 June). Thereport itself discussed ways to increase crop production, but said surprisingly little about how to get meat production to meet growing demand.

Humans evolved to be omnivores. We’re poor converters of most vegetable matter, and gained much in the past from using herbivorous animals to convert grass and leaves into high-quality protein. But in a world where food and land are in short supply, livestock production is a hugely inefficient use of grain. To…