However early the Mousterian culture may have begun, the later stages fall within the range of one of the archaeologist’s most interesting and precise techniques for dating. This is the radiocarbon, or Carbon 14, method.[19] Much simplified, it depends upon the following phenomena: Most plants are radioactive, and so are all animals that depend directly or indirectly upon these plants for food. This radioactivity is found in a rare form of carbon called radiocarbon, or Carbon 14. While a plant or an animal is alive, it contains a constant proportion of this radioactive material. Radiocarbon is always breaking down and disappearing, but while a tree or a bird or another animal lives, this material is being renewed. When this same tree or animal dies, it stops acquiring new radiocarbon, and therefore its radioactivity decreases. Heartwood from a 4,000-year-old sequoia tree is appreciably less radioactive than the living outer layer. Antlers shed by a buck in the last spring are more radioactive than any reindeer antlers left in a cave in France by Old Stone Age hunters 17,000 years ago.
After death, radiocarbon disappears at a rate of speed that can be measured. This rate may seem strange to most laymen. It is based on what physicists call “half-lives.” The half-life of radiocarbon is 5,568 years, give or take a few. This means that after 5,568 years, half the radiocarbon is gone. If the material weighed a pound at the death of the plant or animal, only half a pound would be left. After another half-life of the same length, only a quarter of a pound would remain. And so on and so on. With highly refined techniques, what is left of this radioactive substance can be detected in matter 60,000 to 70,000 years old,[20] and it can be measured and its age determined, with a few percentage points of error, up to at least 50,000 years ago. The scientist must be sure, however, that the material—such as wood, charcoal, peat, antler, shell, bone, or hair—has not been exposed to contamination that would add radiocarbon.
This method of dating, developed by Willard F. Libby in the late forties, supplied archaeologists with fairly close estimates of the age of sites containing wood, charcoal, shell, or bone.
Neanderthal is the first of our early men to have lived within the range of radiocarbon dating. To be more precise, his Mousterian culture has left traces that can be measured. We have several radiocarbon measurements that tell us how recently Neanderthal was around; his oldest cultural materials are beyond the present range of radiocarbon measurement. At Godarville, Belgium, Mousterian artifacts were found underlying an accumulation of peat that dated from more than 36,000 years ago. Since the stone tools were deposited before the peat, they must be at least as old. Charcoal from an ancient hearth in a Libyan cave at Haua Fteah, associated with Levalloiso-Mousterian materials and about three feet or so above a Neanderthaloid jaw, was dated at 34,000 years, or possibly older. The archaeology of this cave suggests that the Neanderthal survived in North Africa until about 30,000 years ago. In Israel, south of Haifa in the Mount Carmel range, at a site called Mugharet-el-Kebara, a very small sample of charcoal, thought to correlate with a nearby Levalloiso-Mousterian deposit, furnished a date of more than 30,000 years.
In the Near East, archaeological excavation directed by Dr. Ralph S. Solecki, of the Smithsonian Institution, turned up yet more material that helps us date the Neanderthal. In the Zagros Mountains of northern Iraq, at Shanidar Cave, in Shanidar Valley, there is a remarkable deposit of both the tools and the bones of early man. The cave contained a dozen feet or so of Upper Paleolithic remains overlying a deep Mousterian deposit. The bottom level of the Upper Paleolithic materials has been dated at over 34,000 years. How much older the Mousterian layers may be we cannot yet be sure. From depths of 14½ and 23 feet below the surface and within the Mousterian deposit, adult skeletons have been recovered. These seem to be Neanderthaloid, as does the skeleton of a child, recovered at a depth of 26 feet. The estimate is that the shallower of the skeletons may be about 45,000 years old, the lower adult perhaps 60,000.[21]
Homo sapiens—New or Old?
The relationship of all these forms of early man is much disputed. For many, many years they were all supposed to be barren offshoots of our ancestral tree. Nobody could find the particular breed of ape-man from which we were descended. Now science is inclined to lump most of them together in one way or another. There are many theories and many genealogies. Swanscombe man plays grandfather to Homo sapiens. Java man and Peking man become the forebears of the Mongoloid. Other men from Java father the Australian, and even the Neanderthal. The Neanderthals breed out their crudeness in some sort of union with Homo sapiens. Or all of them are admitted to the ranks of Homo, with Neanderthal a degenerate offshoot without issue.
The earlier picture was simpler and more dramatic. From Pithecanthropus erectus to Homo neanderthalensis—Java man to the Neanderthal—these creatures bore no relation to our own happy breed. Then, quite suddenly, came Homo sapiens in the person of the Cro-Magnon. He was the kind of tall fellow with a well domed, narrow Nordic head whom Hitler identified with the better class of human beings. Except for the “Red Lady of Paviland,” the first specimens were found at Aurignac, France, in 1852, though nobody recognized the outstanding quality of the skulls until the find at Cro-Magnon, France, in 1868 (see illustration, [page 89]).
SCULPTURE OF THE OLD STONE AGE