The shells of ostrich eggs offer a timeline for some of the earliest
Homo sapiens who settled down to utilize marine food resources along the South African coast more than 100,000 years ago.
Archeologists have learned a lot about our ancestors by rummaging through their garbage piles, which contain evidence of their diet and population levels as the local flora and fauna changed over time.
One common kitchen scrap in Africa—the shells of ostrich eggs—is now helping unscramble the mystery of when these changes took place.
Geochronologists at the University of California, Berkeley, and the Berkeley Geochronology Center (BGC) have developed a technique that uses these ubiquitous discards to precisely date garbage dumps—politely called middens—that are too old to be dated by radiocarbon or carbon-14 techniques, the standard for materials like bone and wood that are younger than about 50,000 years.