African finds revise cultural roots 

 New evidence indicates that people living in Africa 90,000 years ago carved barbed bone points to spear fish and even organized annual fishing expeditions. This discovery challenges the widely accepted theory that the complex thinking and behavior necessary for major cultural changes arose in Europe no earlier than 35,000 years ago.

"What's exciting is that we're seeing strategic planning for subsistence by people who lived so long ago," says Alison S. Brooks, an archaeologist at George Washington University in Washington, D.C. "Humans in Africa invented sophisticated [tool] technologies long before their European counterparts, who have often been credited with initiating modern culture."

 Brooks and John E. Yellen, an archaeologist at the National Science Foundation in Arlington, Va., directed excavations between 1986 and 1990 at a location in eastern Zaire called Katanda. Work there yielded eight barbed bone points, three unbarbed bone points, and a dagger-shaped bone, Brooks and her colleagues report in the April 28 Science. These artifacts were made by grinding a rib or limb bone from a large mammal on a stone anvil or with a stone grinder, the researchers hold.

 Prehistoric Katanda toolmakers cut a row of three-edged barbs on one side of a bone point and carved rings around the base so that it could be fastened to a wooden shaft. Comparable bone implements in Europe date only to 14,000 years ago, Brooks says.

 Excavations also unearthed the bones of many animals. Remains of large catfish turned up in particular abundance. These fish spawn in shallow water during the rainy season, which is probably when the Katanda people made visits to the area, armed with bone-tipped spears, Brooks argues.

 Clusters of artifacts and animal bones at Katanda resemble the debris produced by modern hunter-gatherer families living in the same area, she notes. Current residents still fish, although they now use boats. At other archaeological sites, evidence for organized fishing extends back no earlier than 20,000 years ago.

 Brooks and her colleagues assign an age of at least 89,000 years to the Katanda finds, based on analyses of uranium content and breakdown in several mammal teeth and measurements of the stored radiation dose in quartz sand just above the artifacts.

"This is a highly significant discovery," asserts Jack W. K. Harris, an archaeologist at Rutgers University in New Brunswick, N.J., who directs an Ethiopian excavation. "Technological innovations that gave people a reliable food source occurred much earlier than we thought -- and in Africa rather than Europe."

 An early form of sedentary living may have emerged at Katanda around 90,000 years ago, with settlements set up during annual periods of intense fishing, Harris contends.