Beads Shake Theories on Evolution of Thought

Ostrich egg beads and other artifacts from an ancient site in Tanzania suggest that humans started decorating themselves far earlier than once thought, and in Africa before Europe, U.S. scientists reported Wednesday.

The artifacts have not been properly dated but the scientists believe they are older than 40,000 years. If so, they would challenge two popular theories -- that humans did not develop symbolic thinking until about 35,000 years ago and that when it happened, it happened first in Europe.

The site, at the Serengeti National Park, is at least 40,000 years old and perhaps far older, dating to what is called the Middle Stone Age. Though Middle Stone Age humans were physically modern, there has been debate about their culture and behavior.

The Middle Stone Age in East Africa began as early as 280,000 years ago. The Later Stone Age started about 45,000 years ago.

“This is very precocious,” said John Bower, professor emeritus of anthropology at Iowa State University, who helped lead the study. “The ostrich egg shell beads, the use of bone, the abundant use of pigment -- we found lots of ochre pencils, little bits of ochre that have been rubbed, presumably to make a pigment.”

Bower described the findings at the Loiyangalani River Valley in the Serengeti National Park to a meeting in Montreal of the Paleoanthropology Society.

Stone tools found with the beads and other unusual items are clearly Middle Stone Age in style, Bower said. “But this gives us very broad bracketing dates of 40,000 to 200,000 years ago.”

“The beads are a tantalizing find and once we get some definitive dating it could have a major impact on the issue of the evolution of symbolic thinking,” said Curtis Marean of Arizona State University, who led the study. “We hope that further digging at the site will yield more information.”