The biologist talks about God, Darwin and the end of evolution with John Cornwellby John Cornwell / March 1, 2009 / Leave a comment
When Darwin’s Origin of Species was published in 1859 it didn’t take long for sensible theologians, like Cardinal John Henry Newman, to accept evolution as part of God’s providence. But to this day Christianity remains split between creationist “neats,” who read Genesis literally, and non-literalist “scruffies,” who see Genesis as a myth or a poem.
There is fundamentalism on both sides of the divide. While creationists read the Bible as a cosmological textbook, writers like Richard Dawkins treat evolution as a theory of everything—which is why we have clashed in public. I have always, however, been a keen admirer of the Darwinist professor Steve Jones, who is an eminent biologist and a gifted writer. Jones is professor of genetics and head of the biology department at University College, London. We met recently at his office in the Galton Laboratory behind Euston station to talk Darwinism.
Jones went to grammar school on the Wirral but left at 16 to become an apprentice fitter at the Unilever detergent factory before, via night school, heading to Edinburgh University to read zoology. He is the only biologist to have had the chutzpah to “update” Darwin. He did it in his book Almost Like a Whale, and to celebrate the Darwin bicentenary he has brought out a new book, Darwin’s Island, which examines Darwin’s less-known researches into British flora and fauna.
Dawkins wrote in The God Delusion: “The only difference between The Da Vinci Code and the gospels is that the gospels are ancient fiction while The Da Vinci Code is modern fiction.” Jones, with a more literary background and sensibility, knows better than to contrast scientific fact with unscientific fiction as the ultimate test of truth and untruth (no truthtelling in Shakespeare, or Dostoyevsky?). Yet he is recently on record as insisting, provocatively, that human evolution “has come to an end.” It seemed to me an odd thing to say when there’s such a spate of speculation on the future of human development thanks to advances in biotechnology.
So we have agreed to focus on what evolution tells us about the human future: from technical questions about genetics to historical and cultural views of human progress or retreat.
“There are 200m creationists in the US,” Jones begins, “and I don’t care if they burn my books, so long as they pay for them. Pecunia non olet! It means money doesn’t stink,” he explains. “That’s what Emperor Vespasian said when the Romans objected to him putting a tax on outside urinals—which is why they call them Vespasiennes in Paris.”
He’s swivelling in his office chair, trainer-shod feet firmly up on the desk. And now he’s saying it again: “Human evolution has come to an end!”
“Is this serious?”
“Look, in the developed world men are having their kids on average earlier than in the past. This means that there’s less chance of mutations in their sperm that could lead to evolutionary change.”
Earlier? When I object that UN figures appear to dispute the assertion, he dismisses the interjection with: “Statistics, dear boy. They don’t lie in this instance.”
I’m still not convinced. After all, the average lifespan was much shorter just 50 years ago, so surely men fathered children younger on average. But what I think Jones means is this: that men today breed over a short period, normally only during their late 20s and 30s. In the past, though, most (and especially the most successful) would have had children continuously from adolescence right through until their 50s or 60s. So while the average age at which men today have their first child has got later, the average age at which they have any children is lower.
With another swivel he adds: “Evolution also demands isolated populations that can accumulate adaptation, like the Galapagos Islands. The modern world with its air travel, medicines and protection against the elements means that you’re unlikely to find significant mutations prospering in an isolated habitat. Today’s reproductive universe is different from the past. The weak and powerful, poor and rich, are sexually closer than they were. The average number of children has gone down. The important figure is not the number of progeny people have but the genetic variation in how many children people have.” And the mutations have shrunk.
“The driving force of human evolution is men,” Jones goes on. “Women’s eggs are produced before birth, and in adulthood the number of cell divisions that might give rise to a successful mutation is about 20 between the egg that made her and the egg that fertilises her offspring. But a 28-year-old father’s sperm goes through 300 cell divisions between the sperm that made him and the sperm he passes on. In a 50-year-old man it’s 2,000 cell divisions. So it is older fathers who drive human evolution forward through genetic mutations. But in developed countries most men are now finished with reproduction by their mid-30s.”
And what about mutations resulting from nuclear testing and Chernobyl?
“Sure, your DNA can be affected by environmental influences. But only 0.2 per cent of radiation exposure is man-made; most comes from radon in soil and rocks.”
Jones does however agree that a sort of micro-evolution might still be possible—for example in the spread of genes resistant to HIV/Aids. “Eventually the survivors will pass on their resistant genes to the next generation, creating a generally resistant population. But this doesn’t signal a significant change in the human species.”
What about the idea that humans could become more or less intelligent?
“It was Francis Galton, the early geneticist,” says Jones, “who came up with the idea that human beings were destined to be more stupid because the intelligent have fewer children, while the stupid and feckless breed more rapidly.” Against Galton, Jones cites the “Flynn effect”—the increase of average IQs in the developed world over the past 50 years named after James R Flynn, a political scientist.
Flynn has argued that his “effect” does not demonstrate a genetic increase in intelligence—rather it is due to a bias in IQ tests towards abstract reasoning, which has improved throughout the 20th century due to education and technology. In the past people had the same brain power but less experience of abstract reasoning.
Jones is equally unimpressed with the possibility of genetic engineering leaving a mark on human evolution. He grants that we might see superficial enhancements of human capability, such as Ritalin for concentration, or Provigil to combat fatigue. But these, he points out, are superficial and non-genetic.
We turn next to the possibility of a massive external shock to the human race and how that might affect an evolutionary shift: a devastating epidemic, extreme global warming, a nuclear war, or the kind of disasters—such as a super-collider mishap—pondered by Martin Rees in his book Our Final Century. Rees thinks humanity has only a 50 per cent chance of surviving the 21st century.
“I’m surprised,” says Jones, “that a cheerful chap like Martin Rees writes such a dark, gloomy book.” This leads Jones into talk of the utopias and doomsday dystopias found in literature. “It’s interesting,” he says, “that when writers, like Thomas More, in the distant past fantasised or predicted about utopias, their accounts of human biology remained static while politics and society changed.”
But what about a big cultural change, which could transform humanity as much or more than evolutionary change? We discuss the idea in Galen Strawson’s book Freedom and Belief that society could talk itself out of believing in free will. I mention the famous Twinkie defence of 1978, when a man shot dead the mayor of San Francisco and was acquitted after the jury accepted a plea that his responsibility had been diminished by eating several sugar-laden cupcakes that morning. Some sociobiologists even argue that all our actions are genetically determined—but Jones disagrees and argues that human consciousness, and hence freedom and agency, involves complex social relationships and not just genetic ones.
I want to stay on some of the weirder post-human scenarios. We start with the ideas of the Princeton psychology professor, Julian Jaynes, that the human capacity for self-consciousness was a consequence of a form of mass schizophrenia, first clearly recorded in Homeric literature. In his book The Origins of Consciousness in the Breakdown of the Bicameral Mind (1976) Jaynes asserted that the first indications of self-awareness emerged 3,000 years ago thanks to a benign form of delusion that included the idea that the gods were watching us.
The idea was picked up and recast by the controversial Scottish psychiatrist RD Laing who believed that schizophrenia is the result of parents’ treatment of their children—the fault, for instance, of an unfeeling “refrigerator mother.” Laing later held that schizophrenia was not so much a crucial step in past human evolution, as an anticipation of mental evolution to come. He thought that schizophrenics were privileged human beings.
Jones has a succinct way of dealing with this kind of idea: “I knew RD Laing. He once vomited in my lap at a party!” Jones insists that isolated habitats can’t stay sufficiently isolated to allow mutations, even of the sort Laing is suggesting. He calls it the “great global coalescence,” the way in which humans have escaped evolution’s “pitiless laws of life and death.” He goes on: “Inherited differences in the ability to withstand cold, starvation, vitamin deficiency or disease no longer power the evolutionary machine. People still die for those reasons, but they do so when they are elderly and evolution no longer notices them.”
So all this improvement does not indicate an evolutionary advance?
“Darwin argued that there’s no inherent tendency in evolution to improve matters or make them worse. In fact, there are more likely to be some nasty surprises around the corner. One day we may simply fail in our struggle for survival.”
Much of post-human evolution, as pondered by writers like Francis Fukuyama, Susan Greenfield and Michio Kaku, belongs, we agree, to the realm of cyberpunk fantasy. But there have been straight-faced proposals by serious physicists, such as the idea that “intelligent machines can be regarded as people” (anticipating the Terminator movies), proposed by mathematician John Barrow and physicist Frank Tipler. Human evolution, they argue, will take place within machines. Tipler also suggests that the universe could become a kind of computer that regenerates the whole of human life for eternity.
“I can’t believe that John Barrow believes that stuff anymore,” says Jones sniffily, but he adds that one of the big splits in understanding evolution is between the notions of purpose and of non-purpose. An example of the problem, he goes on, is found in the point—often raised by the intelligent design lobby—about half a wing or an eye: as the half made thing has no evolutionary advantage it must somehow have its final goal encoded within it before it starts its journey. Jones’s answer to these anomalies admits the mystery of the absence of fossil evidence for smooth transitions from, say, no wing, to half a wing (with no evolutionary advantage), to fully operational wing. He attempts to explain it with a mountaineering metaphor that seems, to me, to raise more questions than it answers.
“Evolution,” argues Jones, “often faces the mountaineer’s dilemma. Few peaks are a straight slog upwards to the summit. Instead a climber has to lose his hard-won gains by crossing a valley before he can reach the next high point. Quite how an organism traverses the valley of death is not clear. What is certain is that the intermediate organisms were worse off and must certainly have disappeared.”
It’s this apparent gap in evolutionary theory that has encouraged the “intelligent design” proposition of inbuilt propensities to more complex design. “There are many people who are happy to believe in part of the evolution story,” says Jones, “but argue that God provides a purposive impetus behind it all.”
An example of the teleological fallacy, says Jones, is the view of Cambridge palaeontologist Simon Conway Morris, who is adamant that the course of evolution is “selection-constrained,” revealing a propensity towards a species of intelligent beings. Jones believes that if evolution were run again it would come out entirely differently and human beings might not have existed; Conway Morris believes that a hominid-type intelligent being would be inevitable in any rerun of evolution.
“Conway Morris is a brilliant scientist,” says Jones, “but I don’t get the idea of anything being meant in evolution.”
Yet it is hard, if not impossible, I suggest, for even the most reductionist of biologists to write accessibly about evolution without indulging in a degree of anthropomorphic purpose-talk—even in terms as seemingly neutral as “advantage,” “survival of the fittest,” “adapt.”
As a highly literary scientist Jones professes himself well aware, perhaps guilty, of the overlap between metaphor and science. Darwin himself, he grants, was given to imaginative tropes; his constant companion on the Beagle was a copy of Paradise Lost, while one of the remarkable aspects of the Origin is its capacity to mix metaphor and science to stunning effect.
Apart from the sheer joy of natural description, Jones’s excitement about Darwin’s studies of barnacles and other British minutiae derives from his academic specialisation, genetics. Unknown to Darwin, the study of genetics was initiated during his lifetime by the monk Gregor Mendel in a monastery in Austria with his experiments in cross-breeding different varieties of garden peas. By 1865, Mendel had worked out the existence, at least, of basic elementary factors of biological heredity. They come in pairs, he discovered, one from each parent, and they behave in statistically predictable ways. In the first half of the 20th century it became apparent that these hereditary factors, or genes, were threadlike fibres composed of two types of molecules known as DNA. But how did they work? In 1953, two Cambridge researchers, James Watson and Francis Crick, discovered a successful model for the DNA chemical copying process: the double helix. It replicates by separating its two chains and assembling new chains alongside each of them. It explains how inheritance proceeds on the principle of a kind of information transfer: a process of passing on sameness with the possibility of variation by “mistakes” or “mutations.” All the genetic information necessary for the creation of the eventual organism are contained within the embryo.
“DNA, like the bodies it builds,” says Jones, his eyes aglint, “is itself based on a series of variations-on-a-structure theme. As an egg becomes adult, complex organs—eyes, ears, hands and brains—are pieced together from elements that can be distinguished only in the embryo.” At moments such as this, bringing development biology to life, Jones’s conversation becomes more like the lyrical passages in his books—hymns to the beauty, subtlety, and potential of living creations in their progress “from fertilisation to the grave.”
The link between natural selection and DNA was waiting to happen; in this sense Jones and his biologist peers are Darwin’s direct heirs. “Natural selection,” Jones declares, “leaves its footprints on the double helix in many ways. Long stretches of homogeneous DNA on either side of the European genes for blond hair and milk digestion show that the beneficial variants dragged their neighbours along as they swept through the population over the past few thousand years.”
Darwin apparently wanted to add a chapter on human beings to his work on the origin of farm animals. That chapter has now been written with the aid of modern genetics. Many of the physical changes in the human line since it emerged, Jones contends, resemble those found in domestic animals. “For example, compared with our ancestors, we quarrel less about sex… and, like dogs, men and women copulate all year round, rather than in a short season as do wolves.” As with dogs, sheep and cattle, “various odd human physical mutations have emerged—blond hair, light skin, blue eyes.” As for human intelligence, which enables us to carry on Darwin’s vision in the field of genetics, “Our brains, alone,” says Jones, “have not diminished.”