Homo sapiens—The First Humans Lecture 21
Recent analyses of DNA extracted from Neanderthal skeletons suggest something very, very clear indeed. It suggests that Neanderthal and human lines split more than 500,000 years ago—maybe 600,000 or 700,000 years ago. And what that suggests is that we really are talking about different species. We’re not talking about minor variations on the same species. And that evidence also seems to rule out any possibility that humans and Neanderthals interbred.
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Lecture 21: Homo sapiens—The First Humans
o, here we are. Though tantalizingly close to us, neither ergaster nor Neanderthals display quite the technological creativity that is the birthmark of our species, nor apparently the ability to communicate with the Àuency, precision, and speed of modern humans. Both species disappeared about 20,000 to 30,000 years ago, probably under pressure from our species. The last lecture suggested that our astonishing ecological creativity arises from our capacity for “symbolic” language, which allows us to learn collectively. If this argument is correct, how can we tell when the ¿rst real humans appeared? What evidence could show the presence of symbolic language and a new level of ecological and technological creativity? Unfortunately, the evidence is so sparse and hard to interpret that we have few unambiguous answers. This makes it important to be clear about the sort of evidence we are looking for. In principle, we can imagine two main types of archaeological evidence that might show that the threshold to collective learning has been crossed. The ¿rst is evidence for symbolic language. Of course, language leaves no direct archaeological traces. But it may leave indirect traces. Studies of the base of the skull show how the larynx was placed, which can suggest how well a species could manipulate sounds. Sculpture or cave (or body) painting may indicate that a species was capable of symbolic thought and language.
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