That’s why it is good and proper to have The Selfish Gene celebrated in Matt Ridley’s nice article in Nature. You can tell that I’m preparing to land a punch, can’t you?
Well, sort of. You see, I can’t help but be frustrated at how Matt turns one of the most problematic aspects of the book into a virtue. He suggests that Dawkins’ viewpoint was the inspiration for the discussions of selfish genes presented in Nature in 1980 by Orgel and Crick and by Doolittle and Sapienza. And it is true that The Selfish Gene is the first citation in both papers.
But both cite the book as one of the most recent discussions of the issue. As Orgel and Crick say, “The idea is not new. We have not attempted to trace it back to its root.” So it is not at all clear that, as Matt says, “a throwaway remark by Dawkins led to an entirely new theory in genomics”.
The problem is not simply one of quibbling about priority, however. Matt points out that this “throwaway remark” concerns the “apparently surplus DNA” – in the hugely problematic later coinage, junk DNA – that populates the genome, and which Dawkins suggested is merely parasitic. Yes indeed, and this is what those two later Nature papers discuss – as Orgel and Crick put it, DNA that “makes no specific contribution to the phenotype”.
But is this what The Selfish Gene is about? Absolutely not, and that’s why Dawkins’ remark was throwaway. His contention was that all genes should be regarded as “selfish”. Orgel, Crick, Doolittle and Sapienza are specifically talking about DNA that is produced and sustained by non-phenotypic selection. This, they say, is what we might regard as truly selfish DNA. Now, one can argue about the word “selfish” even in that context – it perhaps only makes sense if this DNA becomes detrimental to the survival of the organism. But the implication is that the phenotypic DNA is then not selfish, and that the term should be reserved for parasitic DNA. That makes good sense – and it is precisely these waters that Dawkins’ title muddied.
I can’t resist also asking what Matt means by saying that “genes that cause birds and bees to breed survive at the expense of other genes”. (“No other explanation makes sense…”) It seems to me more meaningful to say “genes that cause birds and bees to breed survive while helping other genes to survive.” I don’t exactly mean here to allude to the semantic selfish/cooperative debate (although there are good reasons to have it), but rather, it seems to me that Matt’s statement only makes sense if we replace “genes” with “alleles”. This is not pedantry. Genes do not, in general, compete with each other – at least, that is not the basis of the neodarwinian modern synthesis. Although one might find examples where specific genes do propagate at the expense of others, in general it is surely different variants of the same gene that compete with each other. And when a new allele proves to be more successful, other genes come along for the ride. To fail to make this distinction (which of course Matt recognizes) seems to me to propagate a very common misconception in evolutionary genetics, which is that genes are little pseudo-organisms all competing with one another. That isn’t a helpful or accurate way to present the picture.
Matt understands all this far better than I do. So I am quite prepared for him to tell me I have something wrong here.