Puzzling Out Man's Ascent

A young Leakey carries on the search for human origins

  • Share
  • Read Later

(2 of 10)

evidence of man amidst the fossilized bones of long-extinct animals-and the growing sophistication of geologists and biologists— had all but discredited the Ussher-Lightfoot calculations by 1859, when Charles Darwin published On the Origin of Species. Although Darwin did not discuss man in this work, the theory of evolution of species through natural selection suggested that human beings had evolved from some lower form of life. By implying that man was related to apes and monkeys, the great naturalist incurred the derision —and wrath—of millions round the world. "Descended from apes!'' exclaimed the wife of the Bishop of Worcester when she heard the news in 1860. "Let us hope it is not true, but if it is, let us pray that it will not become generally known."

Her prayers were not answered. No less a scientist than Biologist Thomas Henry Huxley further espoused the idea in his 1863 Man's Place in Nature. Darwin won many new converts to his concept in 1871 with the publication of The Descent of Man. Most convincing of all, the fossil record continued to reveal that man had not always existed in his present form. That more primitive men might once have walked the earth was suggested when a skull was found at Gibraltar in 1848 that was more evolved than the skulls of apes but less so than that of modern man. Then in 1856, a similar skull, unearthed in the Neander Valley outside the German city of Dŭsseldorf, showed that at least one of man's probable ancestors (later named Neanderthal man) had a low, sloping forehead, a receding chin, and thick ridges over his eye sockets. Java man, discovered by a Dutch doctor who found a skullcap, or cranium, in 1891 and a thighbone in 1892, was obviously an even earlier, less evolved specimen than Neanderthal. Teeth, a nearly complete skullcap and bone fragments discovered in a cave at Choukoutien, China, during the 1920s established the existence of yet another early ancester, Peking man.* These discoveries helped to convince the remaining skeptics that the earlier finds were not the remains of a freak ape or a deformed human. The ancient, erect-walking creatures had apparently been plentiful and widely distributed; it now seemed indisputable that modern man had evolved from more primitive ancestors. But still not even those who acknowledged his age had any clear notion of man's antiquity. Even the evolutionists saw the whole course of human development as a fairly recent phenomenon, and no one had any real conception of its causes.

In 1924 Raymond Dart, the South African anthropologist, found a startlingly different skull embedded in a piece of limestone from a quarry at Taung—Tswana for "place of the lion"—about 120 kilometers (75 miles) north of Kimberley. Dart determined that the skull had come from a five-year-old primate (the order of mammals that includes humans, apes and monkeys) who had lived on the threshold of humanity. Still, he recognized that the creature was even more primitive than Java man. He named it Australopithecus africanus, or the southern ape of Africa. The skull displayed an odd blend of ape and human characteristics. Dart's creature clearly had a large, apelike face, but its teeth were proportioned like those of a modern man. Its brain, although far smaller than that of a human child, had nonetheless been larger than an ape's. Perhaps

  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
  7. 7
  8. 8
  9. 9
  10. 10