This review is dedicated to the genetically unique Güneş Taylor who, at the moment I am composing this, is writing the final words of her PhD thesis in what Rutherford calls ‘one of the grand endeavours of twenty-first century genetics’. Good luck, Güneş! Good luck, me.
Rutherford’s book is both interesting and disappointing. It is firmly in the popular science category, seeking to make a vital yet complex subject, genetics, comprehensible to the lay reader. As is common with such books, it tends to fall between two stools. It’s neither quite basic enough if you know nothing about genetics, nor sophisticated enough if you do.
As is also common it does offer some insights, kind of ‘take home’ messages that linger in the mind. The first is an indication of just how fast the world of genetics has changed, and how recently. At a conference in 2000, a geneticist opened a betting book on how many genes there were in the human genome. 460 leading geneticists took part over the next three years, with estimates varying between 25000 and 290000 (quite an extreme range!). The actual answer eventually turned out to be about 20000, not even within the range the experts had guessed at.
This anecdote illustrates two key ideas, firstly that the growth of understanding in the field is exponential, and second that the ‘truth’ is always more complex than it looks. One of the problems with agreeing how many genes there are turns out to be that there is no total agreement about what a gene is. Rutherford approvingly quotes (twice) H.L.Mencken: ‘For every complicated problem there is a solution that is simple, direct, understandable, and wrong.’ Rutherford hammers home the point that we cannot look to genetics for simple answers (genes for criminality, for instance).
Another ‘take home’ message is how closely we are all related. In the same way that Jesus was the ‘son of David’, because everybody in his lifetime in Palestine was, so we are all descended from King Solomon (700 wives, 300 concubines), because everybody is. We’re also descendants of Charlemagne. If you have your DNA sequenced by one of the commercial firms now offering the service very cheaply, you will discover that ‘you are of Viking descent, because everyone is. You are of Saracen, Roman, Goth, Hun, Jewish descent…’ (p.152). Indeed the Last Common Ancestor of everyone alive on the planet (all 7 billion) is now estimated to have lived approximately 3600 years ago. As recently as that. We are all cousins under the skin, a fact disguised by a few trivial phenotypic effects such as skin, eye and hair colour.
Beyond this, the book doesn’t have a great deal to offer if you are reasonably interested in and conversant with current genetics – and who else is going to read it? If you know nothing, some of the material may take a bit of grappling with, particularly sections like the one on heritability.
The writing is lively and engaging, but not altogether lucid or elegant. Oddly, this is a characteristic the author shares with his stated mentor, Steve Jones. If you want lucidity and elegance, head for Darwin or Dawkins. With Rutherford you get sentences like: ‘We know that the emergence of the pale skin we associate with Europe, and particularly northern Europe, only emerged in the last few thousand years, just as the genes for processing milk did.’ (pp.250-51) Aaargh. How did the author (or his editor) let that past?
One final point: if you are going to read this book, read it soon. Published in 2016, it’s already out of date, because of the pace of change in research, and it will need updating before 2017 is over.