Sunday, December 26, 2010

Prehistoric encounters

Well before my time, the high school in my native town of Grafton (New South Wales, Australia) was associated with two youths who went on to become world-renowned scholars in their respective domains.

In 1875, 18-year-old Havelock Ellis left his native London aboard a ship—captained by his father—bound for New South Wales. In spite of his lack of teaching credentials, he succeeded in convincing a grammar school in Grafton to hire him as a master. Soon after, the school's headmaster died, and Ellis inherited his job, which he managed to keep for a year... up until his incompetency became blatant.

Back in England, he studied medicine, and ended up becoming a world pioneer in a novel domain: sexology. I might point out that, during my time as a student in Grafton, I don't recall ever hearing of this illustrious gentleman. Retrospectively, I can understand why. In Grafton at the time I attended the high school, no teacher would have ever dared to utter a word such as "sexology". Ignorance was bliss, and the expression "carnal knowledge" designated a crime for which one of my friends (a young cyclist, accused of a brief encounter with a consenting under-age girl) got sent to jail. In another incident, a Grafton shopkeeper was imprisoned for practicing the kind of relationship that Havelock Ellis had analyzed in his first celebrated treatise: homosexuality.

As his given name suggests, Grafton Elliot Smith was born in my future native town in 1871, and he went to school there (where his English-born father was the headmaster) up until the age of 12. He studied medicine at the University of Sydney, and was a resident at the Royal Prince Alfred Hospital. He specialized in brain anatomy, and went on to become a distinguished professor of anatomy in the UK. In an unexpected career switch, he turned to prehistoric anthropology, and even wrote a book on the pharaoh Tutankhamun. Unfortunately, the eminent scholar made the mistake of being bamboozled by a "discovery" that turned out to be a notorious hoax.

That affair had a distinctly negative effect upon the reputation of Sir Grafton Elliot Smith. His so-called diffusionist theories on the spread of human culture had also finally gone out of fashion. Before his prestige paled, Smith had influenced a fellow-Australian scholar who would go on to make a gigantic discovery in paleontology.

Raymond Dart was born in Brisbane in 1893, and he studied medicine at the University of Sydney, where he was a resident of Saint Andrew's College. (I happened to spend 1956 at that college.) In much the same way as Grafton Elliot Smith, Raymond Dart started to get interested in paleontology. In 1924, he discovered an extraordinary skull of a three-year-old child at a place named Taung in South Africa. Around its human-like eye sockets, the skull bore beak marks, suggesting that the Taung Child had been devoured by an eagle. This upright-walking creature had lived 2.5 million years ago, but its brain was as small as that of a modern chimpanzee.

Raymond Dart decided that this creature—part simian, part human—deserved a new genus name. Unfortunately, he invented a clumsy term: Australopithecus, which means "southern ape-man". So, the official name of the Taung Child was Australopithecus africanus. Here's an artist's impression of what the distraught parents might have looked like, as they watched in terror their child being borne away on the wings of an eagle:

Trivial anecdote: When I started to work as an assistant English teacher at the Lycée Henri IV in Paris in 1963, I was intrigued to discover that all the students were familiar with the ugly French translation of this stupid generic term, Australopithèque, which sounds as if it has something to do with Australia. So, it was inevitable that I should receive this term, invented by my compatriot Raymond Dart, as a nickname. How's that for a ridiculous situation? It was hard for me to explain that we Australian citizens—already associated with the people that the French often refer to erroneously as "Arborigènes", since they imagine vaguely that the indigenous tribes of Australia once lived in trees (arbres in French)—had no direct links with so-called "southern ape-men" in Africa.

In fact, the research era during which paleontologists contemplated the forms of fossil fragments, while attempting to invent plausible generic and specific categories, has already drawn to a close. Today, the mtDNA (mitochondrial DNA) extracted from tiny prehistoric relics provides an amazingly precise means of interpreting mysterious paleontological findings. A splendid example of this new approach is provided by the case of the tooth found in the Siberian cave of Denisova.

Not so long ago, it would have been unthinkable to draw any profound conclusions from such an insignificant element. How can we even be certain that it is indeed a human tooth? Well, in fact, it isn't! Analysis of the mtDNA and comparisons with the human and Neanderthal genomes indicate that these so-called Denisovan creatures, who lived in Siberia some 30,000 years ago, were in fact closer to Neanderthals than to the Homo sapiens species.

Both the Neanderthals and the Denisovans had a common ancestor (shown in red) located on a branch that was parallel to that of our human ancestry. But the most extraordinary finding was that these Denisovans (whose known relics were found up in Siberia) apparently did some casual rocking and rolling with the ancestors of present-day Melanesians, in the Antipodes.

God only knows where they held their parties, because it's a long way from Siberia to these Pacific islands to the north-east of Australia. We can be fairly certain, however, that future DNA finds will reveal the addresses of such encounters between humans and Denisovans, no doubt somewhere in Asia.

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