Selfish Genes and Kindly People
When Alfred Nobel instituted his prizes at the beginning of this century, he set up awards in physics and chemistry, medicine, and literature and peace. Since then, in his memory, economics has been added. There are some notable omissions. The story is that Nobel’s wife ran off with a mathematician, so that put paid to the prize opportunities in that field – which may or may not be true but is a good story for all that. As we come to the end of the century, the really glaring gap is biology, although at the molecular level convention now has it that medicine covers this field. It was for this that Watson and Crick, having discovered the double helical structure of the DNA molecule, won their prize. Although if Watson’s autobiography is any guide, the closest either got to medicine was in the arms of off-duty nurses at Cambridge parties. As it happens, in the 1970s the ethologists, Konrad Lorenz, Nikko Tinbergen, and Karl von Frisch, were awarded the medicine prize for their work, but it was a significant exception.
In the early 1980s, the SwedishAcademyof Science, which administers the science and medicine prizes, started a new award. Sponsored by a rich industrialist and his wife, the Crafoord Prize is given in rotation to precisely those areas missed by the Nobels. This year it was the turn of the biologists, and it was awarded to three men: Ernst Mayr, George Williams, and John Maynard Smith. Mayr, now ninety five years old and with more energy than most of my students, is German born but long resident in the USA. He is the world’s most distinguished systematist, and – thanks to his truly great Systematics and the Origin of Species (1942) – one of the founders of the synthesis of Darwinian selection and Mendelian genetics known as “neo-Darwinism.” The wonder is not that he got the prize but that it was so long coming.
The other two men, Williams an American and Maynard Smith an Englishman, were, together with the Englishman William Hamilton (who got the prize a year or two back), those responsible for a very significant redirection of evolutionary theory in the 1960s and early 1970s. It was they who tore evolutionary thought from an almost exclusive emphasis on “group selection” and directed it – directed it back – to an emphasis on the individual. I would say that for the evolutionist this move to “individual selection” was a sea change of the magnitude of the coming of genetics, so let me explain what it was all about.
Charles Darwin’s theory of evolution as expounded in his Origin of Species of 1859 proposed a mechanism: more organisms are born than can survive and reproduce, this leads to a struggle for existence, and then combined with the constant introduction of new random variation we get success in the struggle dependent on the difference between competitors. This is natural selection (or as it later came to be known, the survival of the fittest), and the point is that the differential survival and reproduction leads to permanent organic change, much as the animal and plant breeders’ artificial selection leads to permanent change. What is significant about selection is that it does not merely lead to change but change of a particular type. Organisms have adaptations – characters which help in the battle to survive and reproduce.
Now, right from the start, a major question about the nature of the struggle centred on between whom or what the struggle occurs. Darwin recognized that much of the struggle takes place between organisms and their environment, but also that much of the struggle takes place between organisms themselves. Generally this is fairly unproblematic, from our perspective that is. If a wolf hunts down a deer, that is no more than one might expect. The wolf has adaptations for hunting and the deer has adaptations for escaping. But can one ever have, as surely seems reasonable, a struggle occurring not so much between individuals as such but between groups, especially between the most fundamental of all groups, those interbreeding populations which we call “species”? Somewhat surprisingly Darwin thought not, or at least only on very rare occasions. Why is this surprising? Well surely because it seems obvious that at times one will have a struggle between species – two competitor species for a territory for instance, or two predator species for the same prey. More than this, it seems that there is a trickle-down effect to selection, with some adaptations existing purely for the benefit of the species. Take the phenomenon of hybrid sterility, as for example the mule which is the offspring of horse and donkey. The sterility hardly benefits the mule but it does benefit the two parent species which are not going to produce bastard offspring which are (in a very real sense) neither fish nor fowl.
Darwinhowever could never buy this line of argument. If you are a person who thinks that all of science is a social construction, that is that all of science is simply a reflection of social and cultural ideas, you might suspect that his reluctance was directly a function of the fact that he got the struggle ultimately from the Reverend Thomas Robert Malthus, who stressed (as did so many social thinkers in Darwin’s day) that life is a hard, hand-to-hand existence, with brother turned against brother, and parent against child. Perhaps there is some truth in this suspicion in Darwin’s case, but much more significant was the simple scientific fact that Darwin could never see how the struggle could lead to adaptations which would benefit the group over the individual. Why should the mule give up its sexuality for the good of the group? Let others fend for themselves and the devil take the hindmost. Likewise, if say a wolf spent all of its time hunting for the fellow members of the group, they could basically give up working and freeload on the foolish benefactor. More importantly, they could be out copulating while the hunter was out hunting, and before many generations everyone would be a freeloader and no one would be doing any work, which is hardly a stable state of affairs.
For all that Darwinsaw the significance of individual selection rather than group selection, his insights were forgotten almost from Day One. Alfred Russel Wallace, co-discoverer of natural selection, was an ardent group selectionist – in his case there was a significant social input, namely the life-long influence from his childhood of the socialist mill owner Robert Owen – and it was Wallace far more than Darwin who in this respect set the pattern of thought. Thus things remained down to the 1960s, when the men mentioned above – Hamilton, Williams, and Maynard Smith – seized again the Darwinian initiative showing that selection works almost always at the individual level.
Hamilton’s brilliant insight centered on the hymenoptera – the ants, the bees, and the wasps. Why does one find sterile workers? Can they be slaving simply for the good of the queen and the rest of the nest? Not at all, argued Hamilton. The hymenoptera are haploid-diploid. Whereas females have mothers and fathers – they are born from fertilized eggs – and thus have the usual double set of chromosomes (as do we humans), males have only mothers – they are born from unfertilized eggs – and thus have only a half set of chromosomes. Which means – as one can show simply – that sisters are more closely related to sisters (3/4) than mothers to daughters (1/2). Hence, in raising fertile sisters, sterile workers are benefiting their own reproductive ends more than if they raised fertile daughters. The struggle and consequent selection is something focused on individuals and not groups.
Williams independently saw the truth of what Darwinhad seen and wrote a sparkling book on the subject Adaptation and Natural Selection (published in 1966 and still much worth reading), and Maynard Smith saw how he could apply game theory to evolutionary problems, showing how animals (and plants for that matter) can have certain strategies which they pursue when competing with each other. For instance, in the famous example, if you had a population of competing birds, it would not pay all of the organisms to be hawks (or to be hawk-like), ready to fight to the death. Better in such a situation to be a dove, and run away and live to another day. It would not pay however to be all doves. Better now to be a hawk and grab the goodies. As Maynard Smith showed, what selection will work towards is an “evolutionarily stable strategy” (ESS), where some in a population are hawks and some doves (or a combination of behaviours in the same organism) and an equilibrium will obtain. What Maynard Smith also showed is that, from a group perspective, one expects different results – now organisms are all working as a group and in a sense more efficiently. There really is an empirical difference between the two ways of looking at natural selection – individual and group.
Let me say simply that in the thirty years since these men made the conceptual moves, evolutionary studies has thriven as never before, building on their seminal insights. One empirical study after another has shown the fertility of the individual selection approach. Game theory is an indispensable tool of the modern evolutionist, and what a tool it has proven to be. One species after another – from ants to lions, to chimps, to oaks trees – has shown that behaviour and characters can be understood in a way never before attempted. There really has been a major conceptual revolution. If ever a prize was well deserved, it was the Crafoord Prize for Williams and Maynard Smith and (earlier) Hamilton.
And yet the work is surrounded by controversy, regarded by suspicion by social scientists, philosophers, and theologians. The level of vitriol achieves readings that I have never before seen over anything. At times, it is really abusive and personal. Why should this be so? In part, it is because of the sparkling but provocative polarization of the individual selection perspective by British biologist, Richard Dawkins. The very title of his book, the Selfish Gene, sent tremors down the spine of good Structuralists and good Kantians and good Christians. If you combine his metaphor with the fact that Dawkins today is the loudest biological spokesman for atheism, you know that there has to be something dreadfully wrong.
Then you intensify all of this with the fact that so many evolutionists, working from an individual selective perspective, want to apply their theorizing to the ultimate species, namely Homo sapiens, ourselves. All of your worst fears have surely come true. Whatever the biological merits of the work of Hamilton and company, what we have in effect is a crude and dreadful eighteenth-century, ethical egoism dressed up in the language of modern evolutionary theory. The bottom line is that people are being shown selfish, concerned only with their own benefits and never with the group, and their adaptations – their thinking, their behaviour, their physical being – is nothing more than a way of promoting self over others. No wonder this is anathema to Structuralists and Kantians and Christians, good and bad.
I do not want to say that there is nothing to any of this worry. The behaviour of the Ruse children on Star Island, particularly around the snack bar, strikes me as self-evident confirmation of the truth of selfish gene theory. But let me say simply that to think that this tells all of the story is just bad biology – and to turn from what might for philosophers and theologians and others be just as much of a breakthrough as it has been for evolutionists. Humans are social animals: that is the absolute bottom line. Even with the horrific effects of modern technology, on the murder scale we come out way lower than the lions and the lemmings, the males of which species want nothing more than to take over all the females and kill all of the young and bring the females again into heat and fertilize them. We humans have all sorts of adaptations for getting along. The most obvious to me is that women do not come into heat – imagine trying to run a philosophy course if our sexuality were like that of chimpanzees or dogs.
Being social has big payoffs for the individual. We can do all sorts of things together which we cannot do alone. I am writing this column high above the Atlantic, on a 747 (steerage, I am afraid), on my IBM laptop. Think of how much joint effort has gone into all of that, from the captain to the chap who wrote the software for my word processing. And what this means is that, although genes may be selfish, it by no means follows that individuals can afford to be selfish. Indeed, in many respects we are not – and genuinely not, for if we were all hypocrites merely pretending to get on and help one another we would soon break right down under the strain. The point is that the ants work for one another, but not because they have calculated the genetic relationships and want now to maximize their biological payoffs: rather, their adaptations make them do it. The point is that we humans work for one another, not because we have calculated the biological payoffs and want to maximize personal benefits. Rather, our biology fills us with sentiments about the need to be kindly and cooperative.
This does not make the sentiments unreal, any more than realizing that romantic love triggers various hormones makes the love unreal. They are as real as anything we have. What it does mean is that, thanks to modern evolutionary biology, we can start to get a deeper insight into the causal factors behind human nature. We are really genuinely selfish a lot of the time. You expect that because of biology – if we did not look after ourselves to the exclusion of others we simply would not be here. We are genuinely caring and sympathetic – what biologists call altruistic – a lot of the time. If we did not think and behave this way, we simply could not function as social beings.
What we are then is an uneasy mixture of both – saint and sinner – and this of course is just what philosophers like Plato and preachers like Saint Paulhave been saying since time immemorial. I do not find surprising this coincidence of science and philosophy and theology. Why should truth be opposed to truth? What I do suggest is that you join with me in honouring the Crafoord Prize winners. And the best way to honour them is by taking their work as a stimulating invitation to move forward, rather than as a daunting barrier to further progress and understanding.