This is a subject that is of great interest to me, though I should declare that I am neither a qualified life scientist, nor a formal student of life sciences. I used to engage with the old Open2 forums and I learned a great deal from that. One of the things I encountered through that was this new science they call evo-devo, evolutionary development. Surely one of the key lessons from that, if we begin by taking a simple morphological trait of a species, is that it is unlikely that only one gene is involved in the making of that trait. There are probably several genes involved, possibly dozens. But even if you were to do the hard scientific work and successfully isolate every single gene involved in the making of that morphological trait, still you wouldn’t have the answer as to exactly how that trait was made. You would still have to investigate the embryological process to understand the precise sequence in which those genes were expressed, how the expression of one protein stimulated the expression of another in a long and very complex sequence. In the same way that it is the sequence of amino acids within the protein that govern how it folds and thus what its properties are, so it is the sequence of gene expression that governs the observable phenotypic trait.
So if you think about a behavioural trait, surely that also is likely to involve multiple genes and complex sequences of expression? It always seems to me to be a fundamental misunderstanding when I hear someone talk of ‘a gene for alcholism’ or ‘a thrill seeking gene’ or ‘a criminal gene’. Beyond the nature / nurture debate, it is clear that many human behaviours are genetically programmed, but even the most advanced life science does not yet understand exactly how that works – even in terms of generic principles, let alone the specifics of one particular behavioural trait. I recognise that it is not particularly scientific to talk about what you do and don’t believe, but it does seem to me that some aspects of human behaviour go beyond the merely genetically programmed. Far from criminality being in the genes, what an individual’s genes give them is the ability to recognise the harm that they do and to make a choice about whether or not to do that harm. And into this complexity you can add this two way influence between genes and environment that Dr Hoekstra and Dr Hirst talk about. I am always wary of over playing what science does not know. Life scientists do know a great deal and have achieved the most astonishing things. I know that I have barely scratched the surface of what modern life scientists do know. But my impression is that we are a long way from the true scientific answers to these questions, and I am not entirely convinced that we will ever really know them. I am aware of those physical scientists of far deeper knowledge than me that argue that every human decision can ultimately be explained in terms of the quantum physical interactions that govern chemical activity in the brain. I am not convinced that human beings are quite that clockwork. Who knows, I am here to be surprised and believe me, I am watching this space.
