Wee Fossil Detection Pushes Back Evolutionary Clocks a Billion Years

Elso S. Barghoorn, Professor of Botany and curator of the paleobotanical collection at Harvard, has apparently pushed back the evolutionary clock a billion years.

In a paper presented Thursday at a Geological Society of America meeting in Kansas City, Mo., Barghoorn detailed the discovery of tiny organic fossils in pre-Cambrian rock. A radio isotope test proved that the rod-like bacteria were at least three billion years old.

Until now no organism had been discovered that lived more than two billion years ago. "The age of the earth is presumed to be 4.5 billion years.

Barghoorn found the black rock near Barbetorn, South Africa on an expedition last year. He then brought the specimens back to Harvard where he discovered the fossils, 50,000ths of an inch in length, with an electron microscope.

Barghoorn was assisted in the project by J. William Schopf, a third year graduate student in Biology.

The discovery indicates that the earth's environment three billion years ago was able to support the primitive organism and that the earth could not have been molten at the time.

Another discovery, that of Andrew H. McNair, professor of Geology at Dartmouth cast doubt on the theory that a rapid change in the earth's atmosphere caused an "evolution explosion" in which advanced life forms suddenly developed.

McNair discovered a tiny, clam-like fossil on Victoria Island, Canada, which is according to the radio-isotope method, at least 720 million years old. The oldest advanced organism before the discovery were 600 million years old.

"I knew how gold prospectors felt when they stumbled across the mother lode," McNair said of the find.