People have been acting like people—in other words, they've been making tools, creating rituals, and sharing food—for a long time. That's the conclusion of a recent study from South Africa's southern coast.
There, in a cave perched above the sea, researchers from Arizona State University in Tempe have found evidence that humans were behaving in surprisingly complex ways as early as 164,000 years ago. Our species, Homo sapiens, emerged an estimated 200,000 years ago.
In this cave in South Africa, scientists have found the earliest example of people behaving in complex ways. The chunk of pigment (in the box) is one indication of modern human behavior. Ancient humans may have used it to color their bodies in a type of s
|Mossel Bay Archaeology Project|
The cave held three important clues about the behavior of these Stone Age people.
First, the researchers found the remains of a variety of shellfish, including mussels, giant periwinkles, and limpets. The cave dwellers probably collected these creatures from rocky shores and tide pools and brought them to the cave to eat.
The researchers propose that the early Africans moved to the South African coast between 195,000 and 130,000 years ago. Around that time, the climate inland turned relatively cold and dry. As a result, there were fewer plants and animals to eat away from the coast.
When these ancient people moved to the coast, they probably experienced a major cultural shift, the researchers suspect. That's because observations of modern hunter-gatherer societies suggest that men are more likely to hunt for big animals when people live inland. On the coast, women play a more important role in providing food by gathering plants and shellfish.
As for the second clue, the researchers unearthed 57 pieces of reddish pigment. The researchers think that the cave dwellers used the pigment for coloring their bodies or for other rituals. Symbolic behavior is a distinctly human trait.
Finally, the search turned up more than 1,800 stone tools, including well-crafted blades. These double-edged blades came in a variety of sizes. The smallest were just less than a half-inch wide. Ancient people may have attached these blades to the end of a stick to make spears or other tools. Until now, the earliest evidence of similar blades dates back just 70,000 years.
The new discoveries support the theory that modern human behavior developed gradually, starting about 285,000 years ago, say some experts.
An alternative theory proposes that people developed modern behavior much more recently—perhaps around 45,000 years ago. It's also possible that complex behavior developed at different rates in different places.—Emily Sohn
Bower, Bruce. 2007. Going coastal: Sea cave yields ancient signs of modern behavior. Science News 172(Oct. 20):243-244. Available at http://www.sciencenews.org/articles/20071020/fob2.asp .