New Scientist reviews The Society of Genes
By Bob Holmes
FORTY years ago, Richard Dawkins’ book The Selfish Gene popularised the notion that the gene, rather than the individual, was the true unit of evolution. That view has dominated evolutionary genetics ever since. But in The Society of Genes, biologists Itai Yanai and Martin Lercher say that it’s time to replace the selfish-gene metaphor with a new one that focuses on relationships.
“We are not the simple sum of our genes,” they write. “The members of the society of genes do not live in isolation. Working together, forming rivalries and partnerships, is the only way they can form a human body that can sustain them for a few decades and propel them into the next generation of humanity.”
Their book is not a dry academic argument. Instead, Yanai and Lercher use the idea of a society of genes as a vantage point from which to reintroduce the entire field of evolutionary genetics. It is analogous to modern society, which is full of cooperative and competitive interactions. As in any industry, some genes are workers and builders, while others manage the operation as a whole. This helps us understand the complex genetic networks regulating metabolism and development, where many genes work together and each has multiple functions.
The authors also hope this will give non-specialist readers a more secure grasp of the intricate and often surprising adaptations undergone by living organisms.
Cancer – to take a familiar example – is best understood as a disease of the genome: a breakdown of the usual checks and balances among genes that keep cells from dividing more than they should. No single malfunctioning gene causes cancer. Instead, several members of the society of genes need to fail in order for a tumour to form.
Other chapters apply this to the genetics of immune systems, the evolutionary benefits of sexual reproduction, genetic differences among human populations, the origin of life and more. Many of these insights will be familiar to readers with a good background in evolutionary biology. But even experienced readers are likely to encounter perspectives that are unexpected enough to make the book worth their effort.
For example, the authors speculate why so many elite athletes are of African descent. Because early humans evolved on that continent, Africa still has more genetic diversity than all other continents combined. So, to the extent that genes determine performance, the best genes for any given skill – sprinting, throwing – are likely to be found in Africa. Since genes also affect intelligence, the best chess players ought someday also to come from African ancestry, they suggest. And – although they don’t say it outright – the brightest scientists, too.
The idea of genes working together is nothing new, of course. Four decades ago, Dawkins himself acknowledged that the selfishness of individual genes is tempered by their need to cooperate to keep their carrier organism alive and well. What Yanai and Lercher’s metaphor shift does is revalue those networks of competition and cooperation. They are no longer afterthoughts: rather, they are the centrepiece of our understanding.
Yanai and Lercher take care to assume no prior knowledge, explaining even elementary concepts such as the gene, natural selection and heredity. Readers meeting biology for the first time will be well served by this richer, more nuanced, way of viewing genetics, while those with a deeper background will find plenty of interest, notably in the vivid clarity of the explanations.
(Image: Alexander Nemenov/AFP/Getty Images)
This article appeared in print under the headline “Teaming with life”