Towards the end of Metropolis, Ben Wilson’s panoramic new history of urbanism, the author lists a number of ways in which cities have served to speed up evolution. In Puerto Rico, lizards can now grip bricks and concrete with their toes. Urban birds tend to have shorter wings, which enables them to dodge traffic, and they sing at a higher pitch so that they can be heard above its roar. Most startling of all is the emergence of the London Underground mosquito, ‘an entirely new species that has evolved recently in subterranean areas rich in human blood’ (admittedly, there are limits to its adaptability: a failure to master the art of changing at Piccadilly Circus means that the mosquitoes on the Bakerloo Line are now genetically different from those on the Piccadilly Line).

Wilson, however, is a historian, not an evolutionary biologist, and so his focus throughout is on one particular species. What led humans to start congregating in cities? How have they shaped and been shaped by the experience of urbanism? What are the adaptations made by Homo sapiens that might be