In 1982, the evolutionary biologist Richard Dawkins suggested in his book The Extended Phenotype that its titular concept, normally defined as the totality of an organism’s observable traits, should be extended to all the effects its genome has on its environment. Limiting the influence of genes to an animal’s anatomy is arbitrary, Dawkins claimed. “I find that my kind of paradigm examples are things like beaver dams and birds’ nests, where I’m trying to shake people into realising that you could have a ‘gene for’ a certain shape of birds’ nest, just as surely as you could have a certain shape of beak. You could selectively breed for nest shape. You could do a Mendelian experiment. You could do an artificial selection experiment. You could take a hundred generations to breed weaver birds that make nests of a different shape.