When did our ancestors begin to speak? Tantalizing clues exist. The development of areas of the brain concerned with language seems to have begun in Australopithecus and was well underway in Homo erectus.
In primates and Australopithecus the larynx is located high in the throat, giving a limited range of vocal sounds. We on the contrary have a low larynx and a much larger repertoire of sounds; some tenuous evidence suggests that H. erectus resembled us, although it is unlikely that they yet used any kind of spoken language.
Later hominids probably could speak to some extent and undoubtedly early modern humans did.
In addition to the range of communication possible using animal vocalizations, spoken language can deal with situations not in the here and now, discussing future plans and sharing past experience, for the benefit of the entire social group.
The importance of this cannot be overestimated. H. erectus had increasingly large heads housing their growing brains. In order to be born through the narrow female pelvis, birth had to occur before full foetal maturity, producing weak infants, dependent on adults for some years. A crucial by-product of this was an increased learning period in which many skills and much knowledge could be acquired.
Early hominids, like both modern hunter-gatherers and African apes, lived in groups of several families, probably related. Co-operation within the group was invaluable in defence and food procurement, and the sharing of social interactions a cement binding the group.
Perhaps H. habilis and certainly H. erectus operated from a home base where females and dependent young would stay while males, childless females and juveniles would forage, bringing food back to the base camp to be shared.
