The Origins Of Our Species Essay

This essay has a total of 2016 words and 8 pages.

The Origins Of Our Species

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 been the
climatic changes that swept through the African continent some fifteen million years ago.
The transformed geography, driven by the separation of two tectonic plates, running from
the Red Sea in the north through Mozambique in the south, saw faulting and uplifting of
mountains and the creation of the Great Rift Valley. This transformation caused the
forests to shrink and fragment, creating radical changes to the habitat of the ape
populations.

"The land to the east of the valley was no place for apes, with its forests rapidly
disappearing as rainfall levels diminished", states Richard Leakey and Roger Lewin. "One
very persuasive theory for the origin of bipedalism, the feature that established the
human family, is that it was an adaptation for more efficient locomotion between widely
distributed food sources. There are other theories, too, but this one makes good
biological sense, given the habitat changes of the time." (The Sixth Extinction, p.88.)

Over a period of several million years, new species arose and others became extinct. The
development of hominids with small brains and the ability to walk on two feet represented
a qualitative evolutionary leap. In the fossilized riverbed in Laetoli in Northern
Tanzania are hominid footprints dated at 3.5 and 3.7 million years. In the words of Leakey
and Hay: "the Pliocene hominids at Laetoli have achieved a fully upright, bipedal and free
striding gait, a major event in the evolution of man which freed the hands for tool-making
and eventually led to more sophisticated human activities. Moreover, evidence supplied by
cranial parts of the somewhat later but related hominid fossils from the Afar in Ethiopia
(dated between 2.6 and 3 million years) indicates that bipedalism outstripped enlargement
of the brain. To have resolved this issue is an important step in the study of human
evolution, as it has long been the subject of speculation and debate." (Quoted in The
Labour Theory of Culture by Charles Woolfson).

In fact it was Frederick Engels who first explained this revolutionary birth of mankind as
early as 1876, five years after the appearance of Darwin's 'The Descent of Man', in his
brilliant essay 'The Part Played by Labour in the Transition from Ape to Man'. Engels,
using the method of dialectical materialism, was able to explain the evolutionary process
despite very little fossil evidence. "Labour is the source of all wealth, the economists
assert", wrote Engels in its opening lines. "It is this - next to nature, which supplies
it with the material that it converts into wealth. But it is also infinitely more than
this. It is the primary basic condition for all human existence, and this to such an
extent that, in a sense, we have to say that labour created man himself." (The Dialectics
of Nature, p.279, Lawrence and Wishart 1946.)

Engels recognized that the erect posture in walking represented "the decisive step in the
transition from ape to man." This allowed the hand to be free and could "attain ever
greater dexterity and skill". Thus states Engels, "the hand is not only the organ of
labour, it is also the product of labour." He then went on to explain that this had
further revolutionary consequences. "But the hand did not exist by itself. It was only one
member of an entire, highly complex organism. And what benefited the hand, benefited also
the whole body it served."
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