The latest discovery of a fossil skull in Kenya, more than three million years old, once again demonstrates the complex evolution of humankind. The following article examines the evidence and sees how it fits into the ideas of human origin formulated by Frederick Engels more than 100 years ago.
"There is a grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved." (Charles Darwin, The Origin of the Species, pp. 459-60, Penguin 1985.)
The latest discoveries in paleontology once again reveal the rich and complex evolution of the human species. In March, the magazine 'Nature' reported on a new fossil find in Kenya of a 3.5 million year-old skull. Originally, it was thought that the human linkage had been traced back to an ancestral genus called the Australopithecines (the "Southern Ape"), the most famous remains being 'Lucy', discovered by D.C. Johanson. These proto-humans roamed the savannahs and Rift Valley of Africa more than 3 million years ago, and are closer to modern humans than apes. However, new evidence suggests that the Australopithecus family was not the only hominid species to have existed at this time.
'Nature' describes a new species - Kenanthropus platyops - with a much flatter face than any Australopithecine. "Kenyanthropus shows persuasively that at least two lineages existed as far back as 3.5m years," said Meave Leakey of the Kenya national museum. It is clear that the evolutionary tree is far bushier that at first appeared. While the human lineage split from that of the African apes some 5-10 million years ago, this new evidence suggests possible new lines from which humans evolved. It shows a far greater diversification of human evolution prior to the emergence of the Homo genus.
The newly discovered skull has a small ear hole, like those of chimpanzees. However, it shares other features of early hominids, such as a small brain. But there are other striking differences, including tall cheekbones, small teeth and a flat plane beneath its nose bone, giving it a flat face appearance. The flatter face - a feature once thought distinctly human - arises primarily from the way the new species ate its food.
"It seems that between 3.5 and two million years ago there were several human-like species, which were well adapted to life in different environments, although in ways that we have yet to appreciate fully", stated Dr Daniel Lieberman, an anthropologist at George Washington University, Washington.
It is understood that, as with the Australopithecus, the Kenyanthropus also walked upright. The emergence of these bipedal apes was a revolutionary breakthrough in human evolution. What forced these creatures in this direction is likely to have...