By Bruce Bower
In a cave hugging South Africa’s lush southern coastline, Curtis Marean suspects he has cornered a wily Stone Age crew that brought humans back from extinction’s brink. These plucky refugees of continent-wide desolation were able to pull off such a stunning evolutionary turnaround because they got lucky. A coastal oasis near the bottom of the world spread its sheltering arms in the nick of time.
Marean proposes that it was there, where the Arizona State University archaeologist now conducts excavations, that humankind’s mental tide turned sometime between 164,000 and 120,000 years ago. Seaside survivors learned to read the moon’s phases in order to harvest heaps of shellfish — brain food extraordinaire — during a few precious days each month when ocean tides safely retreated.
Tantalizing traces of complex thinking and behavior, including lunar literacy, have turned up at South Africa’s Pinnacle Point, a cave-specked promontory that juts into the Indian Ocean. Chunks of dark red pigment and strikingly beautiful seashells found by Marean’s team in one cave attest to ancient ritual activities. Stone points unearthed in the same cave sport glossy patches, signs that the rock was heated to make it easier to work with. The finds challenge the long-standing view that Stone Age people did not think abstractly and perform complex rituals until about 50,000 years ago.