Darwin posited that we evolved from a common ancestor in Africa, yet David R Begun points to fossil records showing that Europe is the centre of origin, writes Declan Burke.
David R Begun
Princeton University Press, €28.00
THE idea that humans and the great apes evolved from a common ancestor in Africa is one that goes back to Charles Darwin.
After all, chimps and gorillas, the closest relatives to humans, live in Africa today, and our earliest human ancestors are also African.
It’s logical, then, to assume that the evolution of the ape into the common ancestor of human beings is a purely African story.
Not so fast, says David R Begun.
A world-renowned authority on ape evolution, Begun — a professor of anthropology at the University of Toronto — argues in The Real Planet of the Apes that the fossil record tells us that not only were there also early apes in Europe and Eurasia, but that the European apes represent far more than just an interesting side story.
Indeed, Begun states in his preface that his conclusion is that “it is Europe, and not Africa, that is the centre of origin of the ancestors of living great apes and humans”.
It’s a bold move, contradicting Charles Darwin, although Begun does point out that Darwin, in The Descent of Man, argues for the probability rather than the certainty of the African origins of “our early progenitors”.
Darwin then goes on to clarify his statement by saying that it is useless to speculate on the subject, given the remoteness of the period in question and how often migrations were likely to occur during such a vast time-scale.
Begun, for his part, is cheerfully aware of how his theory flies in the face of received wisdom.
“Few of the ideas and interpretations expressed in this book are exclusively my own,” he writes, before adding, “The few that are mine more or less exclusively tend to be controversial.”
His willingness to point up the potential controversies and flaws in his theory is just one of the reasons why Begun makes for such lively company in The Real Planet of the Apes.
The book is as accessible as palaeontology is likely to get, and it’s peppered with examples of Begun’s offbeat sense of humour, as well as examples of his readiness to give credit where it is due.
Essentially, and although Begun covers the story of ape evolution over the past 30m years, his theory centres on the Miocene period from roughly 10m years ago.
It is at this point that the fossil record begins to reveal Dryopithecus, Rudapithecus, and Ouranopithecus, among others, hominids which appear around the time of the Last Common Ancestor (LCA) of the family that includes humans, chimpanzees, and gorillas (the orang-utan, or Pongo, branched off from the hominids some 5m or 6m years previously; despite its very human features, “the old man of the forest” is much, much older than man).
Primitive apes flourished in Africa about 20m years ago, Begun tells us, although these were more monkey-like than ape-like.
They later dispersed north into Eurasia to more seasonal climates, conditions that then selected for new adaptations in apes, which resulted in apes evolving novel features relating to diet and locomotive and positional behaviour (eg, moving to an upright stance as opposed to horizontal, becoming suspensory apes who hang from branches as opposed to walking along the tops of them).
Then climate changes drove the large-brained, suspensory apes south again, with the ancestors of orang-utans migrating towards south-east Asia and our common ancestor heading due south to the African tropics.
Crucially, Begun tells us, “I was intrigued by the African ape features I found in European fossil apes and the complete lack of evidence for fossil great apes in Africa during the same time period.”
It’s a fascinating theory, even if much of Begun’s book is taken up with the difficulty of establishing the theory based on the fossil record.
“I am determined to falsify this hypothesis,” he tells us. “That may sound strange. But we cannot really prove anything in palaeontology.”
The problem, of course, is not only are fossils so difficult to find, but that intact skeletons of great ape fossils are vanishingly rare.
Begun paraphrases Darwin, who described the fossil record as a book most of which has been erased by time.
“It is a virtual certainty that we have not and probably will never find fossils of more than a small fraction of the species that have ever lived. In many cases it might even be less than 5%.”
Compounding the issue, at least in terms of readability for the layman or laywoman (ie, yours truly), is the fact that many of the fossils Begun relies upon for evidence are teeth.
“Paleoanthropological nerds” such as himself, Begun tells us, have looked at thousands of teeth, and many of the examples of species discovered have been identified on their dental records alone (one example of Griphopithecus, discovered at Engelswies in modern Germany, was identified on the basis of “only one half of a tooth, and a pretty worn one at that”).
The detective work is hugely impressive, certainly, but general readers might find themselves increasingly skipping over those pages dedicated to wear patterns, pointed cusps, dentine horns, and crenulated molars.
By the same token, the book is dotted with fascinating examples of how evolution works, or why a particular species, having evolved to a certain point, then dies out despite being perfectly adapted to its environment.
Oreopithecus, known from fossil sites at Tuscany and on Sardinia, appears to have evolved in isolation on islands (as the Tuscan region would have been roughly 8m years ago), with little by way of competition from other animals or any predators to worry about.
By comparison with its peer Rudapithecus, however, Oreopithecus had a brain less than half its size.
“Reduction in brain size is fairly unusual in evolution,” Begun says, “but Oreopithecus is the exception that proves the rule […] Oreopithecus became the ape version of a tree sloth: Large, suspensory, slow moving, and not especially clever. It is not much of an intellectual feat to move slowly among the branches gathering leaves and other abundant forest resources, especially if you do not have to worry about predators.”
The book ends on a downbeat note when David Begun turns away from sifting through the past and looks to the future. Chimps and gorillas, he reminds us, are both on the endangered list.
“The future for great apes is grim,” he says, as a result of deforestation, the ‘bush meat’ trade and the trade in animal trophies.
“Unless there is a concerted effort internationally to eliminate these markets and there are major changes in governance to provide local people in the countries in which great apes live with more resources to support their families, I do not hold out much hope for the great apes, or most primates for that matter.”
Unless we can find a way to live with our great ape brethren, Begun concludes, we will be the last ape standing.
It’s a conclusion that offers a stark inversion of the playful title of this book, as the human ape precipitates the potential extinction of its closest family relatives.
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