Matthew Holmes, The Graft Hybrid: Challenging Twentieth-Century Genetics, Pittsburgh, Pennsylvania: University of Pittsburgh Press, 2024.
Imagine you had the power to create a new species by simply attaching – “grafting” – two different plants together. You would be holding a graft hybrid, one of the most controversial organisms in the entire history of biology. In The Graft Hybrid: Challenging Twentieth-Century Genetics, I trace the history of these enigmatic beings and explores what makes them so controversial. Over the course of the twentieth century, a series of scientific clashes occurred over the nature of seemingly inexplicable organisms, ranging from multi-colored chickens to black nightshade and tomato hybrids, artificial salamanders to apple and pear tree crosses, all of which were supposedly created by grafting or organ transplantation. The book’s cover depicts one of these graft hybrids: the aptly named Florentine Bizzaria, made by grafting a citron and sour orange tree together. With its strange fruits comprised of alternating sections of citron and orange, the Bizzaria and other compelling organisms convinced many biologists that hybrids could be made by grafting.
For environmental historians, The Graft Hybrid offers new insights into what it meant to think about the “environment” in the twentieth century and how we now perceive and define biotechnology.
For environmental historians, The Graft Hybrid offers new insights into what it meant to think about the “environment” in the twentieth century and how we now perceive and define biotechnology. The rediscovery of Mendel’s laws in 1900 and the subsequent rise of the science of genetics focused on the importance of sex cells as isolated containers and carriers of genetic material, pushing Lamarckian concepts of the direct influence of the environment on heredity aside. The graft hybrid, however, represented a living rebuttal to this new paradigm. If genetic material could be swapped between the connected bodies of plants and animals and then inherited, it would suggest that the entire body of the organism, not just its sex cells, was involved in heredity. This, in turn, suggested that Lamarckian-style changes to the body caused by the environment could be passed down through the generations. This nature versus nurture argument took on political connotations during the Cold War, when the Lysenkoist biology of the Soviet Union harnessed graft hybrids as part of its critique of, and alternative to, Western genetics.
Today, biotechnology is typically associated with specific types of genetic engineering, namely recombinant DNA technology and gene editing. It is these biotechnologies that have transformed plants, animals, and landscapes across the world. Yet as The Graft Hybrid demonstrates, less familiar forms of biotechnology also emerged during the twentieth century. Cell fusion, or somatic hybridization, a technique that emerged during the 1970s, was a kind of microscopic grafting, merging the cells of different plants and animals. Although it never achieved great commercial success, its existence represents an alternative form of modern biotechnology. In the twenty-first century, molecular biology has indicated that grafted plants are indeed also capable of exchanging genetic material and creating hybrid cells. For many Western scientists, grafting is now seen as a supplement to existing biotechnology. For other plant breeders, however, particularly in China, grafting is depicted as a low-cost and accessible alternative to genetic biotechnology with the potential to rehabilitate Lysenkoism. With so much at stake in how we understand biology and grow our food, the graft hybrid controversy shows no sign of going away any time soon.
Feature Image: “Black Hybrid Cherry Tomato” by m_shipp22 is licensed under CC BY 2.0.
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- New Book – The Graft Hybrid: Challenging Twentieth-Century Genetics - November 26, 2024