The Man Who Invented the Chromosome: A Life of Cyril Darlington (review)

Until now Cyril Darlington has mostly been forgotten: relegated, along with his chosen scientific discipline of cytology, to the sidelines of history, both eclipsed by molecular biology with its allure of simplicity, fundamentality, and intrinsic beauty. Compared with the elegance of the double helix, chromosomal chiasmata can appear cumbersome, almost pedestrian, and Darlington himself, tall, aloof, and earnest looking, does not have the mischievous appeal of Jim Watson.

That such appearances can be misleading is the first and most immediate message of Oren Harman's scientific biography of Cyril Darlington. There is at least as much drama in the story of chromosomes and in Darlington's life as in the all-too-familiar race for the double helix. Darlington's childhood was difficult and impoverished. However, his father, a schoolmaster, instilled two complementary passions into young Cyril that would become the foundation of his later career: learning and gardening. After graduating from college, Darlington applied, more by accident than design, for a position at the John Innes Horticultural Institute. He was interviewed by William Bateson and accepted (first as an unpaid volunteer worker). When he left thirty years later to take the position of Sherardian Professor of Botany at Oxford, in that ominous year of 1953, the institution and Darlington himself were widely known and respected. However, a new era in biology was rapidly approaching, and one of the unintended casualties of its success was the rich history of genetics and cytology in the first half of the twentieth century.

Harman does a good job of explaining the complex intellectual and technical problems in genetics and cytology and helps us understand the central importance of cytology to the modern conception of genes and genetic processes. It is in this context that Darlington made a name for himself with the publication of his magisterial book, Recent Advances in Cytology, in 1931. Unconstrained by strong disciplinary allegiances and left largely to his own devices—his mentor, Bateson, himself somewhat of a renegade, died in 1926, and Frank Newton, the promising young cytologist who introduced Darlington to this subject, succumbed to cancer a year later—Darlington set out to provide a theoretical foundation for cytology. His methods—highly theoretical and conjectural—brought him into immediate conflict with his more empirically minded colleagues, but many of his insights about the equivalence of the chromosomal behavior of chiasmata formation and the genetic mechanism of crossing over have stood the test of time.

Darlington's theoretical approach to cytology and genetics is also visible in his second major work, The Evolution of Genetic Systems, first published in 1939 (second edition in 1958). The focus of this book—genetic systems—has quite a modern ring to it, especially in light of recent discoveries in the field of evolutionary developmental biology. Today's insights that phenotypic evolution is largely a consequence of changes in the regulatory elements of the genetic systems would certainly have appealed to Darlington. During his time, Darlington's ideas were at odds with the prevailing conception of population genetics. Unfortunately, Harman does not go into all the details of these debates. A detailed reconstruction of these arguments would help us better understand the different epistemic styles that were present in mid-twentieth-century genetics, as well as provide insights into the origin of the current difficulties of achieving a true synthesis of developmental and evolutionary genetics.

The second half of Harman's book is devoted to a discussion of Darlington's role in exposing the fate of Soviet genetics after Lysenko's rise to power and his ideas about the role of genetics in society. With regard to Lysenko, Darlington clearly stood his ground (unlike Haldane, who had a more difficult time in coming to terms with the Lysenko affair). Less defensible were Darlington's ideas about the genetic determination of human cultural differences, which are problematic at best. Harman provides us with a well-balanced account of Darlington's...