Modern Mind: An Intellectual History of the 20th Century (74 page)

When it occurred, the discovery of Lascaux was the most sensational find of its kind this century.
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Prehistoric art had first been identified as such in 1879 at Altamira, a cave hidden in the folds of the Cantabrian Mountains in northern Spain. There was a personal sadness associated with this discovery, for the man who made it, Don Marcelino de Sautuola, a Spanish aristocrat and amateur archaeologist, died without ever convincing his professional colleagues that what he had found in Altamira was genuine. No one could believe that
such vivid, modern-looking,
fresh
images were old. By the time Robot fell through that hole in Lascaux, however, too many other sites had been found for them all to be hoaxes.
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In fact, there had been so many discoveries of cave art by the time of World War II that two things could be said with certainty. First, many of the caves with art in them were concentrated in the mountains of northern Spain and around the rivers of central France. Since then, prehistoric art has been found all over the world, but this preponderance in southern France and northern Spain still exists, and has never been satisfactorily explained. The second point relates to dating. Lascaux fitted into a sequence of prehistoric art in which simple drawings, apparently of vulvas, begin to occur around 30,000— 35,000 years ago; then came simple outline drawings, 26,000—21,000 years ago; then more painted, three-dimensional figures, after 18,000 years ago. This ‘creative explosion’ has also been paired with the development of stone tools, beginning about 31,000 years ago, and the widespread distribution of the so-called Venus figurines, big-breasted, big-buttocked carvings of females found all over Europe and Russia and dating to 28,000—26,000 years ago. Archaeologists believed at the time Lascaux was discovered that this ‘explosion’ was associated in some way with the emergence of a new species of man, the Cro-Magnon people (after the area of France where they were found), formally known as
Homo sapiens sapiens
, and which replaced the more archaic
Homo sapiens
and the Neanderthals. Related discoveries suggested that these peoples were coming together in larger numbers than ever before, a crucial development from which everything else (such as civilisation) followed.
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Breuil’s view, shared by others, was that the Venus figurines were fertility goddesses and the cave paintings primitive forms of ‘sympathetic magic.’
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In other words, early man believed he could improve his kill rate in the hunt by ‘capturing’ the animals he wanted on the walls of what would be a sacred place, and making offerings to them. After the war, at another French site known as Trois Frères, a painting of a figure was discovered that appears to show a human wearing a bison skin and a mask with antlers. Was this ‘sorcerer’ (as he became known), a primitive form of shaman? If so, it would support the idea of sympathetic magic. One final mystery remains: this explosion of creative activity appears to have died out about 10,000 years ago. Again, no one knows why.

Halfway across the world, much rarer evidence relating to man’s remote past became a direct casualty of hostilities. China and Japan had been at war since 1937. The Japanese had invaded Java at the end of February 1941 and were advancing through Burma. In June, they attacked the U.S. Aleutian chain – China was being encircled. Among these great affairs of state, a few old bones counted for not very much. But in fact the hominid fossils from the cave of Zhoukoudien were just about as important as any anthropological/archaeological relic could be.

Until World War II, such evidence as existed for early man had been found mainly in Europe and Asia. The most famous were the bones and skulls unearthed in 1856 in a small cave in the steep side of the Neander Valley (Neander Thal), through which the river Düssel reaches the Rhine. Found in
sediments dating to 200,000 to 400,000 years old, these remains raised the possibility that Neanderthal man was our ancestor. More modern-looking skulls had been found at Cro-Magnon (‘Big Cliff) in the valley of the Vézère River in France, suggesting that modern man had lived side by side with Neanderthals.
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And the anatomical details of Raymond Dart’s discovery, in South Africa in 1925, of
Australipithecus africanus,
‘the man-ape of South Africa,’ implied that the find spot, a place called Taung, near Johannesburg, was where the apes had first left the trees and walked upright. But more discoveries had been made in Asia, in China and Java, associated with fire and crude stone artefacts. It was believed at that stage that most of the characteristics that made the early hominids human first appeared in Asia, which made the bones found at Zhoukoudien so significant.

Chinese academics raised the possibility of sending these precious objects to the United States for safety. Throughout most of 1941, however, the custodians of the bones dithered, and the decision to export them was not made until shortly before the attack on Pearl Harbor in December that year.
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Barely twenty-four hours after the attack, the Japanese in Beijing searched the fossils’ repository. They found only casts. That did not mean, however, that the fossils were safe. What appears to have happened is that they were packed in a couple of footlockers and put in the care of a platoon of U.S. Marines headed for the port of Tientsin. The plan was for the fossils to be loaded on board the SS
President Harrison,
bound for home. Unfortunately, the
Harrison
was sunk on her way to the port, and the fossils vanished. They have never been found.

The Zhoukoudien fossils were vital because they helped clarify the theory of evolution, which at the outbreak of war was in a state of chaos. Throughout the 1930s, the attention of palaeontologists had continued to focus on Zhoukoudien, in China, rather than Java or Africa for the simple reason that spectacular discoveries continued to be made there. In 1939, for example, Franz Weidenreich reported that of the forty or so individuals found in the Zhoukoudien caves (fifteen of whom were children), not one was a complete skeleton. In fact, the great preponderance were skulls, and smashed skulls at that. Weidenreich’s conclusion was dramatic: these individuals had been killed – and eaten. The remains were an early ritualistic killing, a primitive religion in which the murderers had eaten the brains of their victims in order to obtain their power. Striking as these observations were, evolutionary theory and its relation to known fossils was still incoherent and unsatisfactory.
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The incoherence was removed by four theoretical books, all published between 1937 and 1944, and thanks to these four authors several nineteenth-century notions were finally laid to rest. Between them, these studies created what is now known as ‘the evolutionary synthesis,’ which produced our modern understanding of how evolution actually works. In chronological order, these books were:
Genetics and the Origin of Species,
by Theodosius Dobzhansky (1937);
Evolution: The Modern Synthesis,
by Julian Huxley (1942);
Systematics and the Origin of Species,
by Ernst Mayr (also 1942); and
Tempo and Mode in Evolution,
by George Gaylord Simpson (1944). The essential problem they all sought to deal with was this:
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Following the publication of Charles
Darwin’s
On the Origin of Species
in 1859, two of his theories were accepted relatively quickly, but two others were not. The idea of evolution itself – that species change – was readily grasped, as was the idea of ‘branching evolution,’ that all species are descended from a common ancestor. What was not accepted so easily was the idea of gradual change, or of natural selection as an engine of change. In addition, Darwin, in spite of the tide of his book, had failed to provide an account of speciation, how new species arise. This made for three major areas of disagreement.

The main arguments may be described as follows. First, many biologists believed in ‘saltation’ – that evolution proceeded not gradually but in large jumps; only in this way, they thought, could the great differences between species be accounted for.
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If evolution proceeded gradually, why wasn’t this reflected in the fossil record; why weren’t ‘halfway’ species ever found? Second, there was the notion of ‘orthogenesis,’ that the direction of evolution was somehow preordained, that organisms somehow had a final destiny toward which they were evolving. And third, there was a widespread belief in ‘soft’ inheritance, better known as the inheritance of acquired characteristics, or Lamarckism. Julian Huxley, grandson of T. H. Huxley, ‘Darwin’s bulldog,’ and the brother of Aldous, author of
Brave New World,
was the first to use the word
synthesis,
but he was really the least original of the four. What the others did between them was to bring together the latest developments in genetics, cytology, embryology, palaeontology, systematics, and population studies to show how the new discoveries fitted together under the umbrella of Darwinism.

Ernst Mayr, a German emigré who had been at the Museum of Natural History in New York since 1931, directed attention away from individuals and toward populations. He argued that the traditional view, that species consist of large numbers of individuals and that each conforms to a basic archetype, was wrong. Instead, species consist of populations, clusters of unique individuals where there is no ideal type.
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For example, the human races around the world are different, but also alike in certain respects; above all, they can interbreed. Mayr advanced the view that, in mammals at least, major geographical boundaries – like mountains or seas – are needed for speciation to occur, for then different populations become separated and begin developing along separate lines. Again as an example, this could be happening with different races, and may have been happening for several thousand years – but it is a gradual process, and the races are still nowhere near being ‘isolated genetic packages,’ which is the definition of a species. Dobzhansky, a Russian who had escaped to New York just before Stalin’s Great Break in 1928 to work with T. H. Morgan, covered broadly the same area but looked more closely at genetics and palaeontology. He was able to show that the spread of different fossilised species around the world was directly related to ancient geological and geographical events. Dobzhansky also argued that the similarity of Peking Man and Java Man implied a greater simplicity in man’s descent, suggesting there had been fewer, rather than a greater number of, ancestors. He believed it was highly unlikely that more than one hominid form occupied the earth at a time, as
compared with the prewar view that there may have been several.
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Simpson, Mayr’s colleague at the American Museum of Natural History, looked at the pace of evolutionary change and the rates of mutation. He was able to confirm that the known rates of mutation in genes produced sufficient variation sufficiently often to account for the diversity we see on earth. Classical Darwinism was thus reinforced, and all the lingering theories of saltation, Lamarckianism, and orthogenesis were killed off. Such theories were finally laid to rest (in the West anyway) at a symposium at Princeton in 1947. After this, biologists with an interest in evolution usually referred to themselves as ‘neo-Darwinists.’

What Is Life?
published in 1944 by Erwin Schrödinger, was not part of the evolutionary synthesis, but it played an equally important part in pushing biology forward. Schrödinger, born in Vienna in 1887, had worked as a physicist at the university there after graduating, then in Zurich, Jena, and Breslau before succeeding Max Planck as professor of theoretical physics in Berlin. He had been awarded the 1933 Nobel Prize for his part (along with Werner Heisenberg and Paul Dirac) in the quantum mechanics revolution considered in chapter 15, ‘The Golden Age of Physics.’ In the same year that he had won the Nobel, Schrödinger had left Germany in disgust at the Nazi regime. He had been elected a fellow of Magdalen College, Oxford, and taught in Belgium, but in October 1939 he moved on to Dublin, since in Britain he would have been forced to contend with his ‘enemy alien’ status.

An added attraction of Dublin was its brand-new Institute for Advanced Studies, modelled on the IAS at Princeton and the brainchild of Eamon de Valera (‘Dev’), the Irish taoiseach, or prime minister. Schrödinger agreed to give the statutory public lectures for 1943 and took as his theme an attempted marriage between physics and biology, especially as it related to the most fundamental aspects of life itself and heredity. The lectures were described as ‘semi-popular,’ but in fact they were by no means easy for a general audience, containing a certain amount of mathematics and physics. Despite this, the lectures were so well attended that all three, originally given on Fridays in February, had to be repeated on Mondays.
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Even
Time
magazine reported the excitement in Dublin.

In the lectures, Schrödinger attempted two things. He considered how a physicist might define life. The answer he gave was that a life system was one that took order from order, ‘drinking orderliness from a suitable environment.’
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Such a procedure, he said, could not be accommodated by the second law of thermodynamics, with its implications for entropy, and so he forecast that although life processes would eventually be explicable by physics, they would be new laws of physics, unknown at that time. Perhaps more interesting, and certainly more influential, was his other argument. This was to look at the hereditary structure, the chromosome, from the point of view of the physicist. It was in this regard that Schrödinger’s lectures (and later his book) could be said to be semipopular. In 1943 most biologists were unaware of both quantum physics and the latest development on the chemical bond. (Schrödinger had been in Zurich when Fritz London and Walter Heider discovered the bond;
no reference is made in
What Is Life?
to Linus Pauling.) Schrödinger showed that, from the physics already known, the gene must be ‘an aperiodic crystal,’ that is, ‘a regular array of repeating units in which the individual units are not all the same.’
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In other words, it was a structure half-familiar already to science. He explained that the behaviour of individual atoms could be known only statistically; therefore, for genes to act with the very great precision and stability that they did, they must be a minimum size, with a minimum number of atoms. Again using the latest physics, he also showed that the dimensions of individual genes along the chromosome could therefore be calculated (the figure he gave was 300 A, or Angstrom units), and from that both the number of atoms in each gene and the amount of energy needed to create mutations could be worked out. The rate of mutation, he said, corresponded well with these calculations, as did the discrete character of mutations themselves, which recalled the nature of quantum physics, where intermediate energy levels do not exist.