Bo is sleeping with his eyes closed. I can hardly believe it, but it’s true. I sit on the edge of his bed and listen to his breathing. The pause between exhale and inhale, that’s the loveliest moment of all. Because then, for a fraction, life stands still.
So is that what I want? To make life stand still? Yes. That’s what I want.
Statistically speaking, Bo and I probably share a quarter of our genes, although that percentage may be higher, or even a lot lower – that’s the rotten thing about average values: as an individual, you never know how they apply to you. (But try telling that to an insurance agent.) That Bo has the line of my jaw is therefore probably no coincidence. That his feet are different sizes, just like mine, probably isn’t, either. According to the sociobiologists, now that I know about our blood relationship I will be able to love him more. Although only half as much as when I thought he was my own child, because father and child share half their genes on the average – in other words, twice as many as half-brothers.
This dramatic insight into the relationship between blood ties and love was given us by a certain William Hamilton, who in 1964 published an article in the Journal of Theoretical Biology with the title ‘The Evolution of Social Behaviour’. Hamilton’s article was seen by many as the most important breakthrough in evolutionary theory since Gregor Mendel’s discovery of the hereditary characteristics of the pea. Before Hamilton, Darwin’s theory could be used only to explain egocentricity – social behaviour did not fit within the theory, and was therefore an unpopular field of research for biologists. The only problem was that one could not deny that social behaviour existed, in both animals and humans. Hamilton was the first to provide an evolutionist’s explanation of such behaviour.
In short, Hamilton’s insight was this: social behaviour can provide an evolutionary advantage when it benefits direct blood relations. The quantity of genes shared by the blood relations is therefore the determining factor. From a genetic point of view, the closer the kinship, the greater the advantage of social behaviour over selfishness. Egocentric genes can therefore be served by altruistic individuals.
‘There’s only one problem with Hamilton’s theory.’ It was Dees, of course, who brought this up. ‘It’s a snake biting its own tail. He proves what must be proven on the basis of the presupposition that evolutionary theory is correct, and from the standpoint that there is such a thing as social behaviour.’
But this time I didn’t feel like letting him get away with it so easily. ‘You could,’ I said, ‘develop a hypothesis on the basis of Hamilton’s theory. For example, that humans or animals will be more egoistical in proportion to the extent that other individuals in an experiment are more distantly related. In general, experiments seem to support that hypothesis.’
‘All well and good,’ Dees countered, ‘but the only thing that proves is that the parson always christens his own child first – and that, to put it mildly, is not exactly a scientific breakthrough. If Hamilton is right, there should be a direct relationship between a given gene, or at most a pair of genes, and the social behaviour shown. What’s more, we’re supposed to believe that our genes contain information somewhere that enables us – unconsciously! – to distinguish between close relatives and those three or four times removed. But then you may as well believe in God, or in little green men from outer space.’
I had to admit that I could bring no reasonable argument to bear against that. But the problem with Dees’s criticism of evolutionary theory is that, although he rejects the Darwinists’ answers to the questions of life, he has no answers himself.
And so here I sit beside my sleeping half-brother, who looks like me but then again not. The cuckoo’s egg that my own father laid in my nest. Ever since Bo experienced the love of the girl-with-the-cap, he’s no longer afraid at night. Love makes whole. But can love ever restore what’s been broken between him and me? Will I ever be able to love him again the way I did all those years? And what about him? The only honest answer to those questions is: I don’t know, by God – and not by Darwin either.