"the Gene"

The Gene - An Intimate History

Siddhartha Mukherjee

Bodley Head $26.95

When Charles Darwin’s On the Origin of Species was published in 1859 all copies were sold on the first day, and, as we learn here, “A torrent of ecstatic reviews appeared almost immediately. Even the earliest readers of Origin were aware of the book’s far-reaching implications.”

A similar response greeted the publication of Professor Mukherjee’s own first work, The Emperor of All Maladies, a history of cancer that would win a Pulitzer Prize for literature. It also became a Ken Burns documentary series (shown on SBS).

Somehow, he had fitted in writing that groundbreaking 600-pager around his clinical and academic duties at Cornell, the Mayo Clinic, Columbia University and more.

As he confesses in this equally impressive follow-up, he never expected to be lifting pen again, but then realised there was another story, the one around “normalcy before it tips into malignancy.”

If cancer is “the distorted version of our normal selves”, his focus would shift to “what generates the undistorted version of our normal selves.”

Hence this book, hardly shorter than its forerunner, similarly impressive and immensely readable, despite the challenging nature of the subject material.

“In the early decades of the twenty-first century, we are … constructing a new epidemiology of self: we are beginning to describe illness, identify, affinity, temperament, preferences - and ultimately, fate and choice - in terms of genes and genomes”

His gene journey opens and closes with several members of his own Indian family who had suffered profound mental disorders. Accompanying his father to visit Moni, a nephew with schizophrenia, in an institution in Calcutta, he notes that, “Madness, it turns out, has been among the Mukherjees for at least two generations, and at least part of my father’s reluctance to accept Moni’s diagnosis lives in my father’s grim recognition that some kernel of the illness may be buried, like toxic waste, in himself.”

By book’s end, armed with immensely more information about genetics - as is the reader - he wonders about the “possible trajectories” of the relatives’ lives if they had been born fifty or a hundred years from now.

“This book is the story of the birth, growth, and future of one of the most powerful and dangerous ideas in the history of science: the ‘gene’, the fundamental unit of heredity, and the basic unit of all biological information.”

The early pioneers range from Darwin, the pea hybridiser Gregor Mendel - whose “garden plot may have been small… [but] not his scientific ambition” - and Darwin’s brilliant cousin Francis Galton, “slung between the two giants of modern biology”.

He coined the phrase nature versus nurture, although was unable to quantify the importance of each (not until the 1990s was it proven that genes that control IQ only become significant if the limitations of poverty, hunger and illness are removed).

Galton, a prodigy who knew Greek and Latin by age five, was the founder of eugenics, believing that the “continuous reproduction of softheaded women and men posed a grave threat to the nation.”

A 1912 exhibition on the subject included a German stand extolling ‘race hygiene’ - fast forward twenty years to the Nazis engaging in an array of ‘purification’ experiments.

A more humane version of the Nazis’ ghastly (and discredited) twin studies was work in the 1980s “providing incontrovertible evidence that genes influenced homosexuality more strongly than, say, genes influenced the propensity for type 1 diabetes… and almost as strongly as genes influence height.”

Regarding diseases, rather than traits, a child born to a parent with schizophrenia has from 13-30 per cent chance of developing the illness by age 60.  If both parents are affected, the risk rises to 50 per cent.

The vast canvas includes the haemophilia gene running through Queen Victoria’s descendants, including the Romanovs, and official American policies in the 1920s to sterilise ‘mental defectives’, who were often just people living unconventional lives.

We learn of chromosomal research and by the 1950s are with Watson and Crick, discovering the double-helix structure of DNA, and later the ‘pajama’ study on how subsets of genes allow an individual cell to respond to its environments.

Most genes, says Mukherjee citing Richard Dawkins, behave more like recipes than blueprints: “Human physiology, by analogy, is the developmental consequence of certain genes intersecting with other genes in the right sequence, in the right space.

“A gene is one line in a recipe that specifies an organism. The human genome is the recipe that specifies a human.”

He concludes that if the lessons of history showed “the dangers of empowering governments to determine genetic ‘fitness’… then the question that confronts our current era is what happens when this power devolves to the individual.”