Book Review

Heredity (2000) 85, 410–411; doi:10.1046/j.1365-2540.2000.0819b.x

The Triple Helix — Gene, Organism and Environment

The Triple Helix — Gene, Organism and Environment. Richard Lewontin. Harvard University Press, Cambridge, MA. 2000. Pp. 136. Price £14.50, hardback. ISBN 0 674 00159 1.

Gilean McVean1

1Institute of Cell, Animal and Population Biology, King's Buildings, University of Edinburgh, Edinburgh EH9 3JT, UK

Back in the 1960s, Richard Lewontin was one of the first to use the technique of protein gel electrophoresis for assessing levels of genetic variation in natural populations. It was nothing short of a revolution in population genetics. Yet writing some 30 years later, Lewontin has a less rosy view. 'The result [of protein electrophoresis] was an almost universal abandonment of the research in all aspects of evolutionary genetics other than the characterization of genetic diversity. A single easily acquired technique changed and pauperized ... an entire field of study'.

This book is Lewontin's attempt to tell us what evolutionary biology has been lacking all these years. The message is simple and inescapable: only by looking at the context in which biological traits are expressed can we fully understand the complexity of evolution. Put another way, biology is messy, but it is the mess that is important. This is not a new idea, or even a plea for a new methodology, just an eloquent and dogged iteration of a biological truth. The question is, is it a useful truth? Lewontin is very keen to tell us about the limitations of a reductionist approach and cites plenty of examples where a blinkered gene-by-gene paradigm cannot make sense of biology. But, he is less good at telling us just how we should alter our perspective. About the closest he gets is when he writes: 'It is not new principles that we need but a willingness to accept ... that biological systems occupy a different region of the space of physical relations than do simpler physico-chemical systems'. In short, biology is not physics. I cannot accept this as a useful statement for two reasons. Firstly, it is true to the point of platitude. Secondly, we can learn a lot about biological systems by pretending they do follow simple laws — it is the basis of both population genetics and theoretical ecology. When biology doesn't fit (as is usually the case) we are forced to find out why. Without the reductionist approach we cannot work out what the questions are.

Reading The Triple Helix is rather like being told off for something but not being sure what it is. Lewontin acknowledges that much of the book has 'a distinctly negative flavour' and makes an attempt in the last chapter to be more constructive. However, his solution to the problem of how to think about biology in terms of wider contexts is essentially just that of the reductionist — to identify semi-independent sub-systems and work within these bounds. Yet this is just what biologists do all the time. Nobody studies a gene nucleotide by nucleotide. We do not consider each feather in a peacock's tail as an independent unit. Biology is nothing but the study of how complex traits are made up of many small details. It is the level of our understanding that dictates the focus of current research. Adjust the focus either way, and the picture becomes blurred.