Behavior and Settlement Patterns in Coastal Stone Age Communities – Evidence from Stable Isotopes

Coastlines offer rich resources for hunter-gatherers: abundant food, raw materials for making artefacts, possible routes for dispersal and much more. Were coastal areas therefore important in human evolution?  Opinions have gone back and forth over the years. In the second half of the twentieth century, most researchers thought that aquatic resources became important late in prehistory, once populations had grown so that additional sources of food were needed. Today, different perspectives are being offered, with some researchers suggesting that coastal adaptations may have played a role in the emergence of modern humans. Coastal food resources are relatively abundant, but spatially restricted. Did foraging in this landscape promote the high level of social interaction characteristic of our species? Did early modern humans use seafoods only occasionally, or did they focus on them intensively, like many recent coastal populations? One of the difficulties in answering these questions is that coastal sites are rarely well preserved over very long timespans, due to changes in sea level and tectonic activity. The southern African coastline has, however, remained unusually stable over the last several hundred thousand years, with many well-preserved coastal sites. We find more evidence of seafood in recent sites, but is this due to greater consumption or better preservation? From the isotopic composition of archaeological bones and teeth, we can reconstruct aspects of peoples’ diets and how they used the landscape, and infer some features of the way societies were organized. We cannot yet answer all these questions, but we are making progress!