The discovery of a fossil bone of a man-like creature that has been scientifically dated as 2,500,000 years old was announced Friday (13 Jan.) at Harvard University, Cambridge, Massachusetts.
Harvard press conference with Doctor Ernst Mayr, Director of the Museum (on the left); Doctor Patterson (center), and Professor William Howells (right); fossil elbow bone, and complete arm bone of a modern man for comparison.
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Background: The discovery of a fossil bone of a man-like creature that has been scientifically dated as 2,500,000 years old was announced Friday (13 Jan.) at Harvard University, Cambridge, Massachusetts. If the bone proves to be as old as tests show it to be, it pushes man's history on the earth back 750,000 years beyond present day scientific estimates.
The bone was discovered in 1965 by Professor Bryan Patterson, of Harvard's Museum of Comparative Zoology, on the edge of an ancient lake in a region of open country near Kanapoi in north-western Kenya, not far from Lake Rudolf.
Professor Patterson had led expeditions to the area for several years in search of fossils. The discovery is the lower portion of the upper arm bone, called the humerus, was found on a hot August afternoon in 1965. The surrounding area, which had been periodically covered with outpourings of lava, also contained bones of mastodons, hippopotamuses, elephants and saber-toothed cats. The fact that the bone was contained in this layer of lava made dating it possible. The lava contained potassium, a known portion of which was radioactive as it emerged from the earth. Since the rate of radioactive decay of the various physical elements is known, it is possible to tell how old the bone is within a few hundred thousand years by measuring the amount of radioactive decay of the potassium contained in the surrounding lava.
Geochron Laboratories of Cambridge, Massachusetts has analyzed a number of lava specimens and estimated their age at 2,500,000 years.
Another problem that confronted Doctor Patterson was to determine whether the bone was from a human or an ape. The humerus of a chimpanzee's arm is quite similar to that of a man. A point system was used to tabulate the subtle differences that would distinguish the bone as belonging either to an ape or a man. The information was then fed into a computer which pronounced that it was the bone of a human.
At the news conference, presided over by Doctor Ernst Mayr, director of the Museum of Comparative Zoology, it was pointed out that less than a decade ago the history of man was believed to have begun 600,000 years ago.
Then Doctor Louis S.B. Leakey found remains estimated at 1,750,000 years old in the Olduvai Gorge of Tanzania, to the south of the present find. Doctor Leakey has found jaw bone fragments that tell much about the appearance of Homo habilis.
But since the new find, tentatively known as the Kanapoi Hominid, consists only of a left elbow bone, nothing can be said of the creature's way of life except that it walked upright. No tools were found in the area, and Doctor Patterson suspects this early man was not a tool user.
Kanapoi Hominid lived in a period that the scientists include in the Pleistocene age, although they say the great ice sheets that characterize that period did not begin until later.