Paleoanthropology and Evolution of Humankind

In paleoanthropology one does not have brilliant flashes of insight. There are no E=mc^2 revelations. Recognition comes slowly, almost by hindsight. (Donald Johanson and Maitland Edey in “Lucy: The Beginning of Humankind,” p.271)

A couple of weeks back, I read “Lucy – The Beginning of Humankind” written by Donald C. Johanson and Maitland A, Edey, published in 1981. I vaguely remembered having heard of Lucy or read about it in the news a long time back. It had created quite a stir. I thought that the discovery of ‘Lucy’ was connected with Leakeys, Louis and Mary Leakey, the husband and wife who were hunting, digging and looking for the old fossils of human ancestors in East Africa. When I bought the book, I still thought that the authors would be talking about Leakeys and their find, Lucy. I was pleasantly surprised when I learned that it was Johanson and his team who had discovered Lucy and not in Kenya where Leakeys worked but in Ethiopia.

Although I had been reading the material about the evolution of humankind off and on for a long time, my browsing was quite random. Whenever a book came to my hands, I would read it without making any conscious efforts to study the field systematically. As a result, I could not digest much of the information, which usually included technical terms (particularly the names of the various species) in unfamiliar Latin, Greek and other equally strange languages. I was usually stumped by them. Those terms and nomenclature might make good sense to the specialists but they created almost insurmountable problems for a lay reader like me. For example, consider Australopithecus. At first encounter, I thought it must be an old fossil discovered in Australia but it wouldn’t connect well with the subsequent text. Johanson took care to explain such terms in simple and easily comprehendible English along the way so that reading and understanding became quite easy and effortless. For instance, he explained early on Australopithecus africanus as ‘the southern (Australo) ape (pithecus) from Africa’. So when Australopithecus is mentioned it simply means a hominid discovered in South Africa, which was not wholly man or ape but could be described as ape-man.

The book is also replete with his personal anecdotes showing the development of his own professional career and the mentors who helped him along together with brief biographical information of his team mates and other experts in the fields of paleoanthropology, geology and other related scientific disciplines, whom he met in the course of his work or who impacted his work. It was a pleasant and educational experience on the whole, which I want to share with the readers. And let me state also that this article is for the non-specialist readers. I will start by explaining a few terms at the very outset to avoid confusion and discomfort to the readers.

Anthropology is the science of human beings; it relates to the study of human beings in relation to distribution, origin, classification, and relationships of races, physical character, environmental and social relations, and culture.

Paleoanthropology is an extension of anthropology and deals with the study of old fossils of hominids and other species. Now it is apt to understand what a hominid is. In simple terms, hominid is a member of a family of erect bipedal primate mammals comprising recent human beings together with extinct ancestral and related forms. The recent human beings are descended from hominids. The hominids, the ancestors of humans (Homo Sapiens) and the apes lived millions of years in the past and are extinct now.

The idea of descent from a common ancestor was given by Charles Darwin in 1850s. This idea was so revolutionary that almost all the scientists who were trying to understand the biological evolution accepted it almost immediately because all the pieces of the jigsaw puzzle fell in place. Darwin’s theory created a furor particularly among the clergy because the idea of humankind descending from the apes or ape-men was simply preposterous. A long debate ensued. The scientists started looking for evidence in support of common ancestral descent more intensively. As a result, the science of paleoanthropology came into existence. It became a scientific discipline in itself.
In the beginning, the fossil work done by the paleoanthropologists was tentative and needed additional verification due to less-refined techniques that were available to do the work. For example, dating a given fossil was not very accurate and certain due to approximate methods that were available for this purpose. Discovery of radioactivity at the turn of the last century and subsequent development of radioactive chronometry helped dispelling doubts from the dating results. The potassium-argon method that is currently used among others is quite accurate. Now precedence of a given fossil to another can be established with almost certainty.

Reconstruction of a fossil structure from the numerous excavated pieces was another challenge. There could be no certainty that a fossil specimen developed by reconstruction from a host of pieces was accurate because errors could be made in identifying the various pieces from which the specimen was reconstructed. There always was a certain element of doubt whether all the pieces belonged to the same creature. In view of such uncertainties, forgeries could be constructed of the authenticity of a fossil to support a pre-existing idea. The element of subjectivity was high. One of the historical forgeries in paleoanthropology was the Piltdown man.

A Chimpanzee could Have Done it Quicker

Around 1912, Charles Dawson, an amateur fossil hunter, found two skulls in the Piltdown quarry in Sussex, England. These skulls were touted to belong to the primitive hominids. In the long debates of common descent, the question of the ‘missing link’ would invariably crop up. The missing link pertained to an intermediate species between chimpanzees (the presumed ancestors of humans) and humans. The naturalists were hard at work to find the fossils of hominids, which could settle the debate on the missing link. So Dawson’s discovery was sensational in this respect; it was supposed to be the missing link. It was immediately given the anthropological name of “Esanthropus dawsoni” with the nickname of Piltdown man. Some very highly respectable British names were linked with the discovery of the fossils, if not for actually finding them, but for endorsing their authenticity. For example, Sir Arthur Keith, keeper of the Hunterian collection of the Royal College of Surgeons and president of the Anthropological Institute, wrote in 1931, “ It is therefore possible that Piltdown man does represent the early Pleistocene ancestor of the modern type of man. He may well be the ancestor we have been in search of during all these past years. I am therefore inclined to make the Piltdown type spring from the main ancestral stem of modern humanity.”

Another big name that supported Dawson’s claim was Sir Arthur Woodward, the keeper of the British Museum’s National History Department and a friend of Dawson. In 1915, Dawson found the fossils of Piltdown II. Dawson died in 1916 and Woodward announced the discovery of Piltdown II in 1917.

Owing to the association of such notable authorities, initially there was no reason to doubt the authenticity of Dawson’s claims of the Piltdown man. With the fading of initial euphoria, skeptical voices were raised. According to Richard Harter, “The reaction to the finds was mixed. On the whole, the British paleontologists were enthusiastic; the French and American paleontologists tended to be skeptical, some objected quite vociferously. The objectors held that the jawbone and the skull were obviously from two different animals and that their discovery together was simply an accident of placement. In the period 1912-1917 there was a great deal of skepticism. The report in 1917 of the discovery of Piltdown II converted many of the skeptics; one accident of placement was plausible – two were not.”

However, the doubts wouldn’t simply go away. After 1930, few people would mention Piltdown man authoritatively. For instance, Roger Lewin quoted Sherwood Washburn in his book “Bones of Contention” as saying, “I remember writing a paper on human evolution in 1944, and I simply left Piltdown out. You could make sense of human evolution if you didn’t try to put Piltdown into it.” In 1953, the Piltdown man collapsed altogether; it was determined that it was a case of deliberate fraud. This was said to be “the greatest scientific hoax of this (20th) century.”

The July 10, 1954 issue of Nature asserted, “It is agreed that the skull fragments are human and not of great antiquity; that the jawbone is ape; that they have no important evolutionary significance.”

Numerous books have been written since then on this hoax and the work is still continuing to unmask who was responsible for planting it and why. According to the Daily Sketch, “Anthropologists refer to the hoax as another instance of desire for fame leading a scholar to dishonesty and boast that the unmasking of the deception is a tribute to the persistence and skill of modern research. Persistence and skill indeed! When they have taken over forty years to discover the difference between an ancient fossil and a modern chimpanzee! A chimpanzee could have done it quicker.”

So, How Good is Paleoanthropology?

He (Maurice Taieb) is a scientist, anxious to get at the truth. He does not get hung up on pride. I know anthropologists and geologists who will cling to a point long after it has become overwhelmingly clear that they are wrong. (Donald Johanson and Maitland Edey)

There is a great deal of subjectivity in interpreting the rock fossils found by various anthropologists. Each one of them seeks fame and distinction, which is only human, and in their enthusiasm sometime they are bowled overboard. But now when so much valuable work has been accomplished and many reliable benchmarks are established, it is difficult to create and plant a Piltdown man.

As an example, when Johanson and his team found the fossils of Lucy, he had no difficulty in giving her the nickname of Lucy. She was a female and Johanson and his team mates were so much excited on their find that they celebrated it with a whole night binge of beer, booze, and music. One of the songs they played was “Lucy in the sky with Diamonds”. The fossil got her name from the Beatles whose song it was.

But dating her was not so easy. From the rock stratifications, it appeared that Lucy was more than two million years old, in fact, closer to 3 million. Johanson sent the Basalt samples that were collected by the geologist, Dr. Maurice Taieb, to Ohio for dating. The geologist in Ohio, James Aronson, whom Johanson knew professionally, looked at the samples and declared they were no good because they were contaminated. Johanson suggested to Aronson to come to Ethiopia and collect the samples himself. He agreed but due to a big backlog couldn’t go right away. He went to Ethiopia after several months, looked at the site himself, collected the samples and returned to Ohio. He dated the samples at about 3 million years but worried about the accuracy. He sent his assistant to Ethiopia to look at the site, collect the samples, and do his own testing. His results were close to 3 million years also. Both of them had used different methods of dating. The samples were tested again by paleogeomagnetic method, which yielded a result between 3 and 3.4 million years. Johanson accepted the age of Lucy at 3 million years.

The point of describing all this is to emphasize that with new and better technologies now available and many rival scientists working in the same arena, it is not easy to construct a forgery and run with it. In view of this, one should consider that the modern paleoanthropology is the best available science to comprehend the origins of human life. What else do we have?

Concluding Remarks

I would withdraw that paper today if I could. It stands as an object lesson to me not to be too hasty in the future. I am not ashamed of the descriptions I wrote… But the interpretations – well, I have learned more since, and would make them differently today… I no longer regard Alemayehu’s jaws as belonging to human beings. Nor do I think that Lucy is different from the jaws. (Donald Johanson and Maitlan Edey, Lucy, p.209)

Natural science is quite different from the mathematical science. In mathematical science, such as physics, once a problem is formulated in mathematical terms, its solution follows the mathematical lines logically. There is no subjective tempering in it. Subjectivity can enter in identifying the initial and boundary conditions, which are usually derived from the previous empirical data. In natural science, such as paleoanthropology, there is room for subjective interpretation of the data and the object of investigation, e.g., the fossils. But as better and better technologies and techniques are used, the element of subjectivity is minimized.

There is another difference between the two; a physical theory is capable of making verifiable predictions both ways, that is, it can postdict regarding the events that might have occurred in the remote past and it also predicts the future events. For instance, Einstein’s theory makes postdictions as to what might have happened soon (2-3 seconds) after the big bang and it is also capable of making predictions about what can happen in the far future. The natural science doesn’t have this kind of capability although the specialists believe that it does.

Due to these inadequacies, there is a great room for debate and dispute. This is not to say that the physical science is completely free from debates and disputes but they are settled firmly and rather quickly when empirical evidence is gathered. Such evidence can frequently be collected in laboratories. The empirical evidence of physical science is usually above and beyond doubt. In natural science, there may be a cloud hanging over the empirical evidence which may be due to subjective interpretation of the data. Donald Johanson remarked in “Lucy: The Beginning of Humankind” (p. 257), “My thinking was complicated by a great many things. Listing some of them may give an idea of how hard it is in paleoanthropology to keep your head clear. Not only do you have to keep up with what is going on everywhere, but you have to be aware of your own prejudices and of what effect your association with various other people has on your thinking. There is no such thing as a total lack of bias. I have it; everybody has it. The fossil hunter in the field has it. If he is interested in hippo teeth, that is what he is going to find, and that will bias his collection because he will walk right by other fossils without noticing them.”

Nonetheless, there is sufficient credible information in support of human evolution and the mechanism of natural selection. Physical science increasingly comes to the aid of natural science in evaluating its data. For example, in order to settle the issue of the age of the Earth, radioactive methods of dating cleared the confusion. The creationists believed that the Earth was recent, some 4004 years BC; radioactive methods determined that Earth was about 4.55 billion years old. This is of the order of time that Darwin’s theory of natural selection needed to explain the process of human evolution.

Natural science with the help of the physical science is helping us to understand the origins of human life.