Principles of heredity

Darwin came tantalisingly close to understanding them, 20th-century eugenicists obsessed over them, and with modern science, we are poised to control them as never before. Genes are a constant source of fascination, yet ignorance and misunderstanding plague almost every public discussion of their effects on our health and behaviour. How useful it would be, then, if there was a clear, accurate, and up-to-date pop science book on genetics, a book that recounted the history of genetic science and reflected on its implications for the future of medicine and society. This is the goal of the new book by oncologist-biologist Siddhartha Mukherjee.

It is a lofty goal, and Mukherjee attempts it with lofty language. Except where he throws in some jarring puns, his prose is impossibly grand, bordering on the grandiose. Occasional tinges of purple (‘ancient myth — of the child consuming its father, of Cronus overthrown by Zeus — is etched into the history of our genomes’) may set eyes rolling.

Thankfully, for most of the book, the flowery style doesn’t obscure Mukherjee’s compelling stories of scientific progress. Whether it’s Oswald Avery’s brilliantly straightforward 1944 pinpointing of DNA as the carrier of genetic information, Watson and Crick’s building and rebuilding of their man-sized model of its structure in the 1950s, or the quest to isolate the gene for Huntington’s disease in the 1980s and 1990s, what shines through is the sheer ingenuity of the scientists who have demystified the genome, searching for ‘laws’ that might undergird biology as they do physics.

But although Mukherjee is awed by the intelligence of geneticists, he doesn’t think much of scientific attempts to measure intelligence. Indeed, in one chapter he launches an all-out attack on IQ tests. Why study the genetics of general intelligence, Mukherjee asks, when new evidence from the psychologist Howard Gardner shows that there are actually multiple intelligences? This will come as a surprise to Gardner, who has never provided any data for his now-debunked ‘multiple intelligences’ theory.