Richard Dawkins, whose groundbreaking book The Selfish Gene appeared 40 years ago, bounced back from a stroke this year to publish an expanded edition of his Ancestor’s Tale – a history of all life on earth, and The Extended Selfish Gene. Matt Ridley unravels the code that has made him into a world famous scientist.
Originally published in 1976, Richard Dawkins' The Selfish Gene remains a classic work in evolutionary thought
By Matt Ridley
Insofar as anything was the making of me, Oxford was,’ writes Richard Dawkins in the first volume of his memoirs, published in 2013. The tutorial system taught him how science often has deep questions with no right answers. The world’s ‘top thinker’ – an accolade he won in a poll of 10,000 people from 100 countries in 2013, organized by Prospect magazine – has spent the majority of his life in Oxford, the exceptions being a childhood in Africa, teenage years at Oundle school in the 1950s and an assistant professorship at Berkeley in California in the late 1960s.
It was at his home in north Oxford on 5 February this year that Dawkins, then 74, collapsed with a stroke, to the horror of his many friends and admirers. He has made a remarkably full recovery, complaining only of an occasional croaky voice, a little loss of sensation in his fingers and some unsteadiness on his feet early in the morning. He gave up Twitter for the sake of his blood pressure, but is resuming travel, speaking and writing.
Indeed, his latest book, published at the end of April with his co-author and former student Yan Wong, is in some ways the most ambitious yet: a history of all life. It is a new edition of his groundbreaking The Ancestor’s Tale (2004), but with so much new material as to be almost a different book, 769 pages in length. One of the most intriguing aspects of the book is how new genomic knowledge vindicates in detail the argument in his very first and most famous book, The Selfish Gene, published 40 years ago this year and now re-issued with a new epilogue.Dawkins presenting the updated version of his work on evolution, The Ancestor’s Tale, with Dr Yan Wong (right) this year
The Selfish Gene was based on a series of lectures that Dawkins gave half a century ago, in 1966, standing in for his supervisor, the Nobel prize-winner Niko Tinbergen. At the time Dawkins was a graduate student, doing a series of experiments to show that chicks preferred to peck at images of items lit from above rather than from below, even when they had been reared only seeing things lit from below: implying that the understanding of solid objects as lit from above was instinctive.
In his 1966 lectures, however, Dawkins explored a much more general idea: a new way of looking at evolution, inspired by recently published papers by the theoretical biologist Bill Hamilton. Hamilton had argued that the reason worker ants (for example) devote themselves to raising their sisters (and people to raising their children) was because this had in the past furthered the survival of their genes, sometimes at the expense of the individual. The implication, to Dawkins, was that natural selection is not mainly choosing among species, or groups, or even individuals, all of which are transient aggregations, but among genes.
In his 1966 lecture notes, rediscovered many years later, Dawkins had typed: ‘Genes are in a sense immortal. They pass through the generations, reshuffling themselves each time they pass from parent to offspring… Natural selection will favour those genes which build themselves a body which is most likely to succeed in handing down safely to the next generation a large number or [sic] replicas of those genes… Our basic expectation on the basis of the orthodox neo-Darwinian theory of evolution is that genes will be “selfish”.’
This gene’s-eye view proved to be a fruitful insight, stimulating both empirical research and philosophical rumination in multiple directions – and furious criticism too. As the philosopher Daniel Dennett would later write, ‘Many laypeople and even some biologists may fail to appreciate how bountiful this shift of attention has been.’ Indeed it even has practical applications: it explains the repetitious nature of most non-coding DNA (the key to forensic genetic fingerprinting), and is behind the idea of ‘gene drive’ to spread a gene through all mosquitoes rendering them unable to carry diseases such as malaria or Zika.
In the new version of The Ancestor’s Tale, thanks to Yan Wong’s incisive understanding of genomics, you can see just what Dawkins was getting at. An individual with blue eyes may live for the best part of a century, but the gene that makes her eyes blue is thousands of years old. It has thrived in Northern Europe in many different bodies because it gives its owners some very slight survival advantage (possibly reducing vitamin-D deficiency in sunless climes by also making skin paler).
If the individual has, say, the A blood group, that gene – we now know – is not thousands but millions of years old, which means that for that particular stretch of DNA she more closely resembles a certain monkey or ape than she does, say, her B-blood-group brother. Some genes are probably more similar in a person and a plant than in two different people.
So different parts of the genome tell different stories. Each species alive today is a shuffled deal from a giant deck of DNA cards. For instance, it is generally true to say that as a species we have two closest living relatives – the warlike chimpanzee from north of the Congo river and the peaceable bonobo from south of the river.
Wong has calculated that for about 96% of their genomes, it is true to say that chimpanzees are more closely related to bonobos than they are to humans. But for about 1.6% of the genome, humans and chimpanzees are closer than either is to bonobos; and for about 1.7%, humans and bonobos are closer than either is to chimps. At the level of the genes, the world looks very different.
Likewise, when the first edition of their book was published, Dawkins and Wong were unfashionably cautious about the prevailing consensus, based on mitochondrial DNA, that Neanderthals and modern human beings were distantly related branches of the hominid family tree with no interbreeding. Sure enough, when the rest of the Neanderthal genome was sequenced, it emerged that about 1.2% of the Neanderthal genome is present in the average European, thanks to some rare hybridisation that must have occurred when Europeans’ ancestors first left Africa and met Neanderthals in the Near East or in Europe. But because it is not always the same 1.2%, about 40% of the Neanderthal genome therefore survives inside our species. One species half-survives, genetically, but as a set of features in another species. The same is true of the newly discovered ‘Denisovan’ hominid, identified by its DNA from a fossil finger bone and two teeth in a Siberian cave, but now known to have contributed up to 8% of the DNA of any individual person native to New Guinea and other parts of Oceania. This poses an intriguing puzzle for anthropologists and archaeologists, but it also reinforces the lesson that evolution is the differential survival of genes and vindicates Dawkins’ gene’s-eye view. Species, tribes and individuals are not irrelevant, but they are survival machines built by and for genes.
One reason for Dawkins’ success is that he is not just a thinker, but a fine and persuasive writer too, an artist with words. His arguments have sizzle as well as steak. Whether you agree with him about genes, about his passion for Darwinism, or about his uncompromising atheism – The God Delusion (2006) was a three-million-copy bestseller and brought him even more fame than The Selfish Gene – it is hard to deny that he is a wordsmith of the first order. He knows more poetry by heart than anybody I know and his work is riddled with literary allusions, lightly worn.
To explain: The Ancestor’s Tale is modelled loosely on Geoffrey Chaucer’s The Canterbury Tales, in which pilgrims converse as they converge on the road to Canterbury. The converging pilgrims in Dawkins’ and Wong’s tale are species, starting with us. Imagine that you are walking back up your family tree meeting the other descendants of your ancestors as you go. First, you meet your close cousins, then more distant cousins and so on, a gathering crowd along the road.
For most Europeans the number of ancestors thins dramatically as you approach 60,000 years ago, where you reach a genetic bottleneck caused by the fact that a relatively small population emigrated from Africa around then. Neatly, Wong discovered the signature of this 60,000-year bottleneck very clearly in the sequence of Dawkins’ own DNA. Modern Nigerians have nothing like such a dip in population size among their ancestors.
At roughly six million years ago, you reach the first ‘rendezvous’ with the ancestors of other living species, the chimpanzees and bonobos. The common ancestor of both branches is labelled Concestor 1.
A bit further on, you meet the gorillas’ ancestor, Concestor 2, then the orang-utans’ ancestor and so on. At 65 million years you meet the ancestor of all primates. Surprisingly, Dawkins and Wong discovered that there are just 40 such rendezvous, and 40 concestors, before you reach Canterbury, the origin of life itself. Some of the concestors were large animals, some tiny. Respectively, they resembled modern apes (no 3), rats (12), lizards (16), newts (17), fish (18), worms (26) and so on.
At some of the rendezvous, just a few modern species join. Rendezvous 18 brings in just three species of lungfish, 19 brings just the coelacanth, 22 brings just the lampreys and hagfish. At others you meet a vast crowd of other species. Rendezous 11 brings all the rodents, 16 brings all the birds, lizards and tortoises, 26 brings all the insects, spiders, crustaceans, snails, squid and clams, 34 brings the fungi and 36 the plants. Concestor 40, if you’re wondering, is where we meet bacteria. At each stage in the book, ‘pilgrims’ join to tell their tales to illustrate particular themes of evolution and genetics. It’s a book to take to a desert island.
How to depict this vast tree of life in a single diagram has long baffled scientists and artists alike. Including the whole tree of life in one diagram would require a sheet of paper larger than the solar system. Wong’s colleague James Rosindell has solved the problem in a most ingenious way with his ‘OneZoom’ software, adopted in The Ancestor’s Tale. While walking with Luke Harmon along the famous ‘sandwalk’ at Down House, where Charles Darwin did his thinking, they had the idea of representing the tree of life in ‘fractal’ form – so it looks similar at different scales.
OneZoom is a spiral tentacle, where you can zoom in on any part and find smaller spiral tentacles at many scales. As you zoom towards the branch between the animals and the plants, you find the sub-branches of animals, and the sub-branches within each group of animals. It is salutary, given our egocentricity as a species, to find that you have to take a minor side branch to reach the primates, another minor side branch from the monkeys to reach the apes, and then mankind appears as just one little twig. You can choose an obscure species and sponsor it for a fee, so its picture gets included, but be warned there is a ban on sponsoring a hagfish for your ex.
Mention of computers reminds me of how I first met Richard Dawkins. It was 1976. I was an 18-year-old first-year undergraduate; he was a 35-year-old lecturer. I had just read his exhilarating new book
The Selfish Gene, but he was standing in front of me giving a lecture not on evolution, but on how to program computers. Among his many other talents, Dawkins was a pioneer of computer simulation, as a way of testing Darwin’s idea of natural selection.
A poetry-reciting, computer-programming, best-selling, word-coining, game-changing, deep-thinking evolutionary biologist made in Oxford – that’s Richard Dawkins.
Matt Ridley (Magdalen, 1976) is an author of non-fiction books on science and a columnist for The Times. He sits in the House of Lords as Viscount Ridley. His degree at Oxford was in zoology.