From a single cell to Miocene primates

Human evolution, in its full sense, begins with the origin of life on Earth, nearly four billion years ago. Most aspects of modern human biology were established long before we split off from chimpanzees, including many aspects of genetics, neuroscience, and cognition that are relevant to language evolution. It remains a regrettably common mistake to think of human evolution as “beginning” with our split from chimpanzees some seven million years ago – this simply marks the time we have been evolving independently of any other species that happens to be alive today. Had Neanderthals survived a few thousand more years to the present day, this arbitrary timespan would be greatly reduced. Were great apes to become extinct, it would be greatly increased. In this chapter, therefore, I examine the great sweep of human evolution from its beginning – the origins of life and the first single-celled organisms – focusing particularly on aspects of genetic control, neuroscience, and vocal communication that are relevant to language.