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

    Forgotten Prophet of Genetics The Man Who Invented the Chromosome: A
    Life of Cyril Darlington. Oren S. Harman. xii + 329 pp. Harvard
    University Press, 2004.

    Cyril Darlington was an impressive figure: Well over six feet tall
    with a frame to match his height, handsome and debonair, a fresh rose
    in his jacket lapel, Oxford's Sherardian Professor of Botany looked
    the part. Although he was, in his day, one of the foremost cytologists
    in the world, he was also an enthusiastic student of history and a
    devoted gardener. He learned to garden as a child and subsequently
    expressed this enthusiasm in the genetic garden he created at the
    University of Oxford and in the historic Botanic Garden there; he also
    planned two arboreta (both achieved). His passion to account for
    history in genetic terms led him to write a mammoth book, The
    Evolution of Man and Society (1969).

    The son of a Lancashire schoolmaster, Darlington graduated from Wye
    College with a London University degree and found unpaid work at the
    John Innes Horticultural Institute, which was directed at that time by
    William Bateson, an "apostle" of Mendelism. Sixteen years later
    Darlington became director. By the time he left in 1953 (after 30
    years) to assume the chair of botany at Oxford, he had built for
    himself and the institute an international reputation.

    Like Darwin, Darlington was systematic in preserving documents
    pertaining to his life and work. His papers are a treasure trove for
    the biographer. Oren Solomon Harman has made full use of them in The
    Man Who Invented the Chromosome, supplementing them with interviews of
    surviving colleagues. The book has four main sections, devoted to
    Darlington's early career, his major creative period in cytology at
    the John Innes Horticultural Institute, his response to Marxism and to
    Lysenkoism (which in the 1930s resulted in some Soviet geneticists
    being declared "enemies of the people" and shot), and his public
    statements about his genetic view of man and society.

    Harman encompasses this agenda in an evenhanded manner, avoiding as
    far as possible making personal judgments about his subject. This
    cannot have been easy, because Darlington's strong hereditarian and
    racist pronouncements, many of them laced with derision and ridicule,
    invite challenge. But no matter how objectionable Darlington's
    utterances on race, class, intelligence, culture and history, Harman
    keeps his cool. Instead of fulminating, he lets his sources mete out
    the judgments. At the end he muses on the story he has told: "No one
    can remain indifferent" to it, he opines, or to "the lessons it offers
    about the interplay of ideas and the way we express and act on them."
    For Harman, "the passionate expression and vigorous challenge of new
    ideas, and their application to society, is where the future of
    mankind lies."

    The title of the book signals the disputed status of the chromosome in
    the 1920s and points toward the imaginative and creative synthesis of
    the subject that Darlington achieved. By the time he entered the field
    in 1923, a consensus had developed regarding how chromosomes assemble
    at the onset of cell division and then split in two, with each
    daughter chromosome traveling to opposite poles of the cell. But the
    division process leading to the formation of the sperm and egg was
    disputed territory. Here, like chromosomes (paternal and maternal)
    associate in pairs. Do they associate end-to-end or side-by-side?
    Using plants, Darlington established that it is the latter. He went on
    to sort out the puzzling case of the association of chromosomes in
    rings in the evening primrose, and as a theorist he both clarified and
    unified chromosome behavior across the board in his book Recent
    Advances in Cytology (1932), a tour de force. But his method, although
    it drew upon a wealth of data, was conjectural, involving a degree of
    speculation that empirically inclined biologists were reluctant to
    accept.

    Harman brings out clearly the central feature of Darlington's
    conception of cytology: his view that the chromosome is a dynamic
    unit-a vital part of "the genetic systems" that organize and suppress
    to varying degrees the indeterminacy of mutation and recombination.
    Control of cell division, control of the degree of inbreeding or
    outbreeding, and control of sterility or fertility are genetically
    based, he thought, and the genetics of these systems is itself subject
    to selection, just as are the genes that determine other traits. With
    such a view, Darlington could not but deplore the naivete of the
    population geneticists' equations, which to all intents and purposes
    treat the gene as an independent unit in heredity. Yet, like the
    population geneticists, he wanted to approach the genetic system from
    an evolutionary point of view. These ideas he first aired in a chapter
    of Recent Advances in Cytology, but in 1939 he expanded on them in The
    Evolution of Genetic Systems. Genetic systems, he explained, "rest on
    a basis of chromosomes and are related to one another by processes of
    natural selection." This combination of "the material basis with the
    evolutionary framework," he declared, "provides the only means of
    making sense of biology as a whole."

    The greatest strength of Harman's book lies in the exposition and
    analysis he provides of Darlington's views on the evolution and
    history of man and society. It is, of course, a starkly hereditarian
    view, but Harman shows its organic relation with Darlington's
    biological conception of genetic systems.

    The fact that until now there has been no full-length biography of
    Darlington underlines the extent to which he has been forgotten. The
    molecular revolution left him behind, and the political climate
    rendered his views on man and society increasingly unacceptable.
    Harman's biography is therefore especially welcome. It is a valuable
    source for the student of the biology of the first half of the 20th
    century, and Harman's discussion of Darlington's genetic approach to
    the historical and social realms is penetrating.

    No biography of a cytologist is likely to make an easy read.
    Cytogenetics is a very visual science. Those unfamiliar with its
    jargon and visual content will need more assistance than Harman has
    provided. Without helpful photographs of the stages in meiosis as seen
    through the microscope, it is difficult for the uninitiated to grasp
    why interpreting them proved so difficult. Also, Harman would have
    been wise to focus more strictly on the relation between Mendelian
    heredity and the chromosomes rather than including the
    Mendelian-biometric debate and much else. That said, he has provided a
    scholarly, powerful and at times devastating, but also subtle,
    analysis of his subject.-Robert Olby, History and Philosophy of
    Science, University of Pittsburgh

    Control of cell division, control of the degree of inbreeding or
    out-breeding, and control of sterility or fertility are genetically
    based, Darlington thought, and the genetics of these systems is itself
    subject to selection.

    Robert Olby, History and Philosophy of Science, University of
    Pittsburgh

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    Published: 2004/11/02 03:00:14 CST