A DRAMATIC shift in diet sometime during the evolution of modern humans has left its imprint on our genome. The discovery could provide some of the strongest evidence to date in support of a controversial hypothesis that purports to explain why humans, alone among all the apes, suddenly evolved such big brains.
One plausible reason is that early hominins suddenly stumbled on a new, rich food source capable of fuelling a large, energetically expensive brain. For many years, anthropologists presumed the crucial food source was meat, which became more accessible as our ancestors began to use stone tools for…
