Sally McBrearty and Alison Brooks
The Revolution that Wasn't
Tracing the origins of Homo sapiens through the fossil record is fragmentary. First of all, the fossils themselves are fragmentary, containing only some of the bones of any given specimen. Only a small number of fossil specimens is found for any given species and these are often spread out in different sites and come from different times. Finally, there is significant variation within any given species (look at today's humans!) so any small sample of individuals can be misleading when extrapolating to the entire population. Therefore, paleontologists look for clues in other ways that might reflect on the culture, capabilities and even the appearance of any given extinct species. These include looking at other artifacts that are found adjacent to the fossils like tools, pottery, jewelry, wall engravings, other animal fossils, and other clues.
Sally McBrearty and Alison Brooks have done just that regarding the years leading up to the emergence of Homo sapiens and have described this work in their beautifully written article in the Journal of Human Evolution, "The Revolution that Wasn't: A New Interpretation of the Origin of Modern Human Behavior."
They demonstrated that the culture and behaviors we associate with modern humans (us!), like wall painting, jewelry making, fishing and tool-making, did not just appear suddenly. Instead, they emerged over a long period dating from 280,000 years ago through about 50,000 years ago. These cultural changes were associated with a number of our predecessor species as well as our own in our transition from archaic humans to modern humans.
This work makes it clear that there wasn't some abrupt, sharp delineation between pre-Homo sapiens and Homo sapiens. Rather, there is a continuum of changes that evolved over two hundred thousand years or more. Will this also be true regarding our evolution to a successor?
Sally McBrearty is a professor and head of the Department of Anthropology at the University of Connecticut. Alison Brooks is Professor of Anthropology and International Affairs; Director, Center for the Advanced Study of Hominid Paleobiology at the Elliott School of International Affairs at George Washington University in Washington, DC.
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