The fact that humans can speak is dependent on the evolution, not just of the brain, but of the articulating apparatus – the larynx, the tongue and so on – and of respiratory control. That is why birds can imitate human speech, whereas apes, our nearest relatives, cannot: birds have the necessary equipment, in order to be able to sing. Through some fascinating detective work we can tell from looking at human skeletons when it was that the necessary developments in control of the tongue and larynx, and of the muscles of respiration, developed. That turns out to be from a time long before – from other evidence – we believe we developed language. So what were these developments for?