Newly found fossils confirm Darwin's predictions

April 23, 2010|By ALLAN POWELL

The April 9 announcement of the discovery of partial skeletons of a 9-year-old boy and a female about 30 years of age in South Africa was another confirmation of evolution.

These fossil bones, estimated to be about 2 million years of age, also support the "out of Africa" predictions as the birthplace of pre-human primates leading to human beings.

Many who are interested in the development of evolutionary thought are aware that Darwin published "The Origin Of Species" in 1859. It introduced the concept of evolution by natural selection.

They might not, however, be aware that in 1871, Darwin published "The Descent Of Man," which applied the principles of his theory to the evolution of primates and Homo sapiens (man the wise). It was in this second great book that Darwin exhibited great prescience by predicting that Africa would be the most likely place on Earth for the appearance of primates leading to more advanced forms of development.


According to Darwin, "In each great region of the world the living mammals are closely related to the extinct species of the same region. It is therefore probable that Africa was formerly inhabited by extinct apes closely allied to the gorilla and chimpanzee; and as those two species are now man's nearest allies, it is somewhat more probable that our early progenitors lived on the African continent than elsewhere."

A casual look at the locations of several of the fossil discoveries made by paleontologists shows how much Darwin was on the mark.

In 1924, Raymond Dart found the Taungs Child in South Africa. In the 1930s, the famous Leaky family discovered a series of rare primate fossils at Olduvai Gorge. In 1974, Donald Johanson discovered "Lucy" in Ethiopia. More recently, in 2008, Lee Berger and his son discovered the two partial skeletons in South Africa.

It is amazing that genetic evidence permits the statement that the DNA of one of man's closest relatives, the chimpanzee, shares 98.5 percent of the DNA of human beings. While Darwin was not aware of this genetic basis of such similarity, he was well aware of other structural likenesses.

There will be a repetition of the same objections to earlier evidence for evolution on the grounds that too much is left to chance. It is argued that chance could not result in such a complex organism without the guiding hand of an intelligent designer. For whatever reason, they are unaware that evolution depends on two processes - one dominated by chance and the other dominated by predictable causal law.

The genes that determine biological characteristics are indeed subject to change or mutation. These replicators, as they are now called, are not perfect in their replication and these variations eventually result in new species. The second process, natural selection, is a selective process that is dependably predictive. Over time, this selective process results in the survival of improvements that might give the impression of design. But again, the process is a natural, expected result.

The primacy of Africa as the birthplace of progenitors that eventuated in the development if Homo sapiens is confirmed by the fossil record according to author Jerry A. Coyne, a professor specializing in evolutionary genetics at the University of Chicago. In "Why Evolution Is True," he affirms, "The fossils are scattered in time and space, a series of dots yet to be genealogically connected. And we may never have enough fossils to join them. But if you put these dots in chronological order, you see exactly what Darwin predicted: fossils that start off apelike and become more and more like modern humans as time passes."

We are fortunate to have the fossils that have so far been discovered. Each find helps to unravel the mystery of human origins. Blood and soft tissue cannot survive the ravages of time. Bone has a better chance, and if it was covered with sediment and then hardened, it is more likely to be preserved for this needed evidence and the historical record. We then have links that suggest a chain to hold the story of human evolution together.

Allan Powell is a professor emeritus of philosophy at Hagerstown Community College.

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