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The Selfish Gene

Natural selection works at the level of the gene.

On the ‘selfish gene’ view of evolution

It partly depends on whether you’re reading the book or reading the title only, which an awful lot of people, I’m sorry to say, have done.  So a lot of people have read it as, ‘Oh, this is all about selfishness’.  It’s saying that people are selfish or, even worse, it’s saying that people ought to be selfish, and of course it’s neither.  It’s saying that genes are selfish in a very special sense, which is the sense that natural selection works at the level of the gene, that’s to say when we talk about the natural selection of entities in a pool of entities, what we’re talking about is the natural selection of genes in a pool of genes.  Superficially it might look like natural selection of individual organisms but it only is insofar as individual organisms reproduce and if you boil that down what that really means is that it makes genes more numerous in the gene pool.  So you can either talk about natural selection as favouring those individuals who maximise, in the technical term, their inclusive fitness, which is a fairly complicated mathematical function, or you can talk about natural selection maximising genes that work for their own survival.  Genes work for their own survival via individual organisms by making them good at surveying, making them good at reproducing, good at attracting a mate, good at parental care and it all boils down to one thing, which is gene survival.  So if there’s anything selfish in the world of life it’s the gene.  That may mean that individual organisms are selfish and to a large extent perhaps it does, certainly in certain species, but if gene selfishness is best served by individual altruism or individual cooperation, individual generosity, then that’s what you’ll get.  So ‘The Selfish Gene’ explains individual selfishness, individual altruism, it explains all kinds of things and it always boiled down to this one thing.  Gene survival, meaning it’s genes that are working to increase their numbers in the gene pool.

On Bill Hamilton and the ‘gene’s eye view’

The ‘gene’s eye view’, which is the view of my book ‘The Selfish Gene’, yes, Bill Hamilton is largely responsible for putting that forward.  In the 1960s, in 1964 especially, I read his 1964 papers pretty soon after they came out under the influence of my great friend and mentor Mike Cullen and was immediately totally inspired by Hamilton’s papers.  I was invited by Niko Tinbergen, my then boss, to take over his lectures for one term when he went on sabbatical leave at Oxford and I did.  I took the, what to me then was the quite daring decision to give great weight to Hamilton’s ideas, which were then pretty new and not many people knew about them.  And I went straight for the gene’s eye view, which was not actually entirely what Hamilton did.  Hamilton, having fully understood the gene’s eye view in an earlier paper in 1963 in the American Naturalist, actually expounded the gene’s eye view totally at the gene level, in the ’64 papers he kind of reverted to the individual organism level and he asked himself the question, ‘How would I need to change the theory we already have about the individual organism’, being the level at which we, or through whose eyes, let’s say, we see natural selection, what’s the minimum change we’d need to make in an individual’s eye view in order to reconcile with the gene’s eye view, which is what’s fundamentally going on?  And he coined the mathematical function inclusive fitness.  In inclusive fitness you can informally define…I’ve informally defined it as that quantity which an individual organism will appear to be maximising when what’s really being maximised is gene survival.  So it’s as though the individual organism takes a decision, ‘What should I do in this situation with all these complicated circumstances, what should I do in order to maximise the long term future of my genes in the gene pool?’  Needless to say we’re not talking about literally, consciously, taking that decision.  Natural selection favours those individuals whose nervous systems calls them to behave in such a way that they appear to be taking that view.  

So the gene’s eye view as Hamilton originally put it forward in 1963 and as I put it forward in 1976, and in my lectures of 1966, really does look entirely at the level of the gene and says, ‘What would I do if I were a gene trying to maximise my survival in the gene pool?  How would I manipulate every individual body in which I find myself in order to maximise my own survival?’  And I went straight for the gene jugular, so to speak, and Hamilton did it in 1963, but it’s as though in 1964 Hamilton was diverted from that course, reverted to the individual organism and then tried to reconcile the gene’s eye view with the individual view and modified the individual view in such a way as to make it the same thing as the gene’s eye view.  And I think that might’ve been a mistake.  I think it might’ve been better to carry on with the straight gene’s eye view which is what I did in my 1966 lectures when I took over from Tinbergen which…by the way, the sort of rhetoric I used in that 1966 lecture is almost identical, I recently noticed, I recently discovered my old lecture notes, almost identical to the rhetoric I was later to use in ‘The Selfish Gene’, the sort of immortal genes leaping from body to body down through the generations and so on.

On any changes to be made to ‘The Selfish Gene’

In a way there’s disappointingly little in the way of warts that I would change in ‘The Selfish Gene’. I mean, I say disappointingly because scientists like the idea of changing their mind when new evidence comes in.  An awful lot more is known about genomes and how they work but that really doesn’t affect the fundamental idea of the gene’s eye view of natural selection.  I think one thing that I would change is just one sentence really.  I think I said somewhere near the beginning of ‘The Selfish Gene’ something that gave the impression that individual organisms are selfish.  And, ah, that was unfortunate because that’s not the message I would…that I really wanted to convey.  The message that I wanted to convey was that individuals may be selfish, they may be altruistic, but genes are always selfish.  And gene selfishness may manifest itself in the form of individual selfishness or individual altruism.  The reason that I put that unguarded, unwise sentence in was, as so often, you have to think about the climate that I was arguing against at that time.  And the climate that I was arguing against was a more group selection view, the sort of idea that individuals work for the good of the species and I was bending over backwards to oppose, to fight against that extremely common misconception which was rife in the 1970s and 1960s so I bent too far over backwards.  I forget the exact phrase I used but it was to the effect that we should expect genes to be selfish.  What I meant was we should not expect genes to be concerned with the survival of the species.  We should expect them to be concerned with the survival of their genes and if that leads them to be selfish, so be it, but it may also lead them to be altruistic.