The Deeper Genome

The early 2000s saw the completion of the sequencing of the human genome, announced with great hype partly on the basis that it would enable extraordinary medical advances. In the event, single gene conditions are comparatively rare, and a much more complex picture has emerged, represented by the publication of the results of the ENCODE study in 2012. It had been thought that up to 98% of DNA was junk, but it now turns out that at least 80% has a regulatory function. For me, the crucial shift in thinking has been from a linear atomism typified by reductionist microbiology to a more systemic field understanding of the genome as a whole in epigenetics. Just as the original evolutionary thinking spoke only of the adaptation of the organism to the environment rather than the interaction between the two in Gaia theory, so the central dogma of Weismann and later Crick has proved a limited way of thinking: the genome has turned out to be much more dynamic and interactive, with many genes responsible for regulatory mechanisms within the environment. So the picture is one of complexity rather than simplicity.

I found it fascinating that over 4 million 'switches' are scattered around the genome devoted to 'controlling' (this is also a metaphor) the activity of 22,000 genes. This means that the similarities between humans and other mammals are far less than supposed by genetic make up alone. The book takes the reader through the development of this thinking from Darwin onwards so that one can appreciate how modern theories have been formulated. He discusses the work of Jacques Monod, Barbara McClintock and Conrad Waddington, among others, and explains the vitriolic reaction to the ENCODE findings not only in scientific terms, but also for the potential support they might be seen to give to the intelligent design position. In his conclusion entitled 'the case the complexity', the author goes back to the Romantic movement of the early 19th century, including the work of Goethe, about whom he might have written more (it was not clear that he was familiar with modern developments of Goethean science). He remarks that 'the methods available to study the complexity that they recognised in nature were far too simple to do justice to it', a contention that he also applies to a purely reductionist approach in trying to simplify a complex process. It is encouraging to read that this approach might have reached its limit and needs to be incorporated in a more holistic understanding as in genome-wide association studies. This is more consistent with similar pictures emerging in quantum physics and ecology - representing a complex web of interactions.