Ethiopian finds and feuds.

Separate investigations in Ethiopia last year uncovered the oldest firmly dated hominid stone tools and a largely complete Australopithecus boisei skull. But a dispute between two research teams over the boundaries of their excavation areas in Ethiopia erupted at the meeting into public charges of unethical conduct and vigorous denials of the accusation.

The controversy concerns an area known as Gona, which lies next to the Hadar geologic formation. Hadar excavations have yielded 3- to 4-million-year-old fossils of A. afarensis, including the famous partial skeleton of Lucy.

Work at Gona from 1992 to 1994 led to the discovery of 21 new sites containing thousands of stone artifacts and ancient animal remains, reported Seleshi Semaw of Rutgers University in New Brunswick, N.J. Numerous sharpened stone flakes, as well as the rocks they were chipped from, date to between 2.5 million and 2.6 million years ago. This is the oldest solid evidence of stone tool manufacture. The estimated age relies on an analysis of argon isotopes in a volcanic ash layer just above the finds and evidence of a previously dated reversal of Earth's magnetic field in sediment just below them.

Continuing research at Gona will address whether hominids used stone implements substantially before 2.5 million years ago, Semaw says. Some scientists argue that a global climate change around that time sparked a relatively sudden shift to stone tool use by hominids.

Excavations in 1993 and 1994 at Konso-Gardula, another group of Ethiopian sites, produced a 1.5-million-year-old A. boisei jaw, along with much of that specimen's fragmented braincase, reports Berhane Asfaw of Rutgers. Homo erectus inhabited Konso-Gardula at the same time (SN: 1/2/93, p.6).

Excitement over the new Ethiopian discoveries was tempered by the charge, leveled by Semaw and then repeated by Asfaw, that researchers from the Institute of Human Origins (IHO) in Berkeley conducted an October 1994 excavation in Gona outside their official research area and within the area secured by Semaw's team.

Semaw calls the IHO activity "professionally unethical."

According to Semaw, a native Ethiopian, he and Rutgers' Jack W. K. Harris first obtained government permission to work in specific parts of Gona in 1987, although a ban on anthropological research was officially in effect at that time. Semaw's research at Gona will make up his doctoral thesis.

The IHO team, headed by Donald C. Johanson, William H. Kimbel, and Robert Walter, returned to Hadar in 1990, after the research ban was formally lifted. From 1991 to 1994, the IHO project submitted annual proposals to Ethiopian officials for research zones that encroached more and more upon the adjacent Gona permit area, Semaw argues. Last year, IHO scientists worked as many as 12 miles outside their government-sanctioned research zone, he contends.

IHO's Kimbel calls Semaw's accusations "ludicrous and false." IHO received government approval for its proposed permit areas from 1990 through 1994 and did not intrude into the research zones of other scientists, he holds.

Semaw and Harris have filed a complaint with Ethiopian officials and expect a ruling later this year.

This situation follows a bitter organizational split at IHO last year. IHO's board of directors fired the staff of the geochronology laboratory after IHO's single largest donor withdrew his financial backing. Fired IHO scientists formed the Berkeley Geochronology Center (BGC) and have filed suit against IHO to retain the lease for their facilities as an independent research organization.

Paul R. Renne, BGC's president and a former IHO employee, conducted argon dating of volcanic ash from Gona as part of Semaw's research team.