All social animals communicate with each other, from bees and ants to whales and apes, but only humans have developed a language which is more than a set of prearranged signals. Ourspeech even differs in a physical way of the communication of other 1animals. It comes from a cortical speech centre which does notrespond instinctively, and organises sound and meaning on a 2rational basis. This section of the brain is unique to humans. Whenand how the special talent of language developed are impossible to 3say. But it is generally assumed that its evolution must have been along process. Our ancestors were probably saying a million years 4ago, but with a slower delivery, a smaller vocabulary and above alla simple grammar than we are accustomed to. 5 The origins of human language will perhaps remain foreverobscurely. By contrast the origin of individual languages has been 6the subject of very precise study over the past two centuries. There are about 5 ,000 languages spoken in the world today(a third of them in Africa), but scholars group them together intorelatively a few families—probably less than twenty. Languages are 7linked to each other by sharing words or sounds or grammatical 8constructions. The theory is that the members of each linguisticgroup have descended one language, a common ancestor. In many 9cases that original language is judged by the experts to have beenspoken in surprisingly recent time—as little as a few thousand years 10ago.