A Dominant Character The Radical Science and Restless Politics of J. B. S. Haldane

Students of genetics and evolution might be familiar with the name of J.B.S. Haldane (1892-1964), particularly for his contributions to population genetics. What I did not realise before reading A Dominant Character was that he had many more strings to his bow and was a larger-than-life character. In a fascinating biography that never seeks to downplay his complicated character, journalist Samanth Subramanian effortlessly switches back and forth between Haldane's personal life and his many scientific contributions.

Haldane was not an easy man. In his interactions with others, Subramanian characterises him as grouchy, delighting in provocation, and blunt to the point of hostility. His life offers plenty of drama for a biographer to work with. Following his father's example, he routinely experimented on himself for his physiological research on respiration, locking himself in airtight chambers or snacking on chemicals to change the acidity of his blood. He unexpectedly relished the experience of trench warfare during World War I: "what mystified even him, although only in retrospect, was his taste for the violence and pleasure he took in killing an enemy" (p. 88). But two decades later, during voluntary visits to a Spain torn by civil war, the "lopsided nature of power in aerial bombing" (p. 218) deeply unsettled him. His first marriage started as an affair while she was still married and became a public scandal when a tribunal ejected Haldane from his biochemistry readership at Cambridge, which he overturned in an appeal. His second marriage similarly blossomed from an affair while his first marriage frayed over childlessness and mutual infidelity. And at the age of 65 he emigrated to India, publicly announcing his disgust with Britain's handling of the 1956 Suez crisis.

Besides these colourful episodes, there were two difficult topics where I thought Subramanian excelled in neither vilifying nor exonerating Haldane, but presenting him as the complicated, contrarian person he was.

First was that of eugenics, which was all the rage at the beginning of the 20th century. Though Haldane considered "many of the deeds done in America in the name of eugenics [...] about as much justified by science as were the proceedings of the inquisition by the gospels" (p. 138), in a 1928 speech he commended the work done by the Eugenics Education Society. Subramanian adds that "to his credit, he would go on to revise this notion, arguing decades later that human diversity was not only desirable but was a signal of social liberty" (p. 139). Regarding race, Haldane "scoffed at any nostalgia for bygone racial perfection [yet] could still lapse into shoddy generalization [...] He was not a bigot, but he was also not fully exempt from the preconceptions held by those around him" (p. 139-140).

Second was his strongly held political convictions, which landed him in far hotter waters. He slid from socialism in his youth to communism in adulthood, enamoured by several visits to the Soviet Union. MI5 took a keen interest in Haldane but was never able to decide whether he represented a threat. Subramanian clears him of recently made accusations of being a Soviet spy, "if espionage involves the deliberate transfer of secrets to another state, nothing stains Haldane's innocence at all" (p. 257). Instead, it is the Russian agronomist Trofim Lysenko that stains his reputation. Lysenko pushed a pseudoscientific idea of inheritance of acquired characteristics and applied this to crops, promising greatly enhanced yields. Once he secured the backing of Stalin, he purged Soviet academia of the dangerous Western idea of genetics. Numerous scientists were arrested and murdered, including a good friend of Haldane, the famous seed collector Nikolai Vavilov. And yet, Haldane could never muster more than half-hearted criticism of Lysenko, and always while arguing his ideas had some merit. Subramanian insightfully concludes that this was about Haldane's "[...] emotional attachment to the party. Admitting he was wrong about Lysenko would mean admitting he was wrong about Communism and the nature of Stalin's regime" (p. 262).

Despite his many flaws and idiosyncrasies, Haldane was also a genius, and Subramanian effortlessly weaves Haldane's many scientific achievements into his narrative. This was a time when Mendel's findings had only just resurfaced and various other explanations were still competing with Darwin's notion of natural selection. Haldane wrote a series of ten papers, collectively known as A Mathematical Theory of Natural and Artificial Selection, that provided just that. It made him an important contributor to the nascent discipline of population genetics and what later became known as the modern evolutionary synthesis. He made the first estimates of mutation rates in humans and, in a paper written with his sister, demonstrated the first example of genetic linkage (certain traits inheriting together because of their proximity on a chromosome). His work on heterozygote advantage in thalassemia patients preempted findings on sickle cell anemia. And his name lives on in Haldane's rule (the observation that sterile or inviable hybrids are usually the heterogametic sex), the Oparin-Haldane hypothesis (life arose from biochemical reactions between organic compounds), and the Briggs-Haldane equation that describes enzyme kinetics.

If that was not enough, his 1924 book Daedalus predicted peak oil, the switch to wind and solar energy, the hydrogen fuel cell, and test-tube babies. From the 1930s onwards he started writing popular science articles on virtually every topic under the sun in numerous newspapers and magazines, and he started a lively correspondence with readers. Subramanian beautifully captures the spirit of his inquisitive mind: "On every front of science, he seemed to know every journal article being published, every item of research being conducted, as if scientists confided their dreams to him every morning before heading off to their laboratories" (p. 4).

A Dominant Character is the third biography of Haldane after Ronald Clark's in 1968 and Krishna Dronamraju's in 2017. The latter was the last PhD student to work with Haldane before he died. Not having read these I cannot compare them to A Dominant Character. What I will say is that this book is well researched. Subramanian has drawn on archives at eighteen institutes in five countries and some of his footnotes are so detailed that you know exactly what to expect if you were to check these out for yourself. More importantly, Subramanian braids together Haldane's academic genius and his colourful personal life into an incredibly enjoyable biography that effortlessly switches back and forth between the two. A book that is hard to put down once you start it.