Margarita Saona reviews Mary Roach’s “Replaceable You: Adventures in Human Anatomy,” where science, cyborgs, and animals come together as we think about the human body.
In her introduction to her most recent book, Replaceable You: Adventures in Human Anatomy, Mary Roach seeks to assure her readers, declaring: “There are no cyborgs clanking through these pages.” They might not be clanking, but they are there. I contend that cyborgs are precisely what the book is about. Roach’s statement is an attempt to distance herself from science fiction and to establish her commitment to the present, to actual medical feats. However, it is clear that she is dealing with technological interventions on organisms. From dentures in the 1700s to the 21st century attempts at 3D printing organs, we humans have been tinkering with our bodies to adapt to our environment or to make up for parts we miss or that have stopped working. That is what Manfred E. Clynes and Nathan S. Kline had in mind when they coined the term cyborg in their 1960s article in Astronautics (Clynes and Kline 1960). I would say that Roach’s book is a comprehensive and irreverent journey through mankind’s cyborgization.
Replaceable You is Mary Roach’s eighth book on the New York Times bestseller list. Her approach to science writing incorporates humour into detailed accounts of complex stories, using language accessible to the general public. It covers a wide range of topics, including organ transplantation, prosthetics, skin grafting, plastic surgery, colostomy bags, and the gene editing of pigs to produce organs suitable for xenotransplantation. The light-hearted tone that pervades the book makes it fun, entertaining, and easy to read, while also immersing the reader in both the technical aspects of using CRISPR on pigs to grow human organs and in moving stories of people struggling with the stigma of ostomy. During her book tour at the Harvard Book Store, science journalist Elizabeth Preston asked Roach a question that puzzles many of her readers: how does she balance grim or painful topics and dry humour? (Harvard Science Book Talks and Research Lectures 2025, 10:39). Roach acknowledges it is not always easy. Sometimes she just changes the tone for a segment that requires more sensitivity, and sometimes she trusts her editor’s advice and removes certain parts. However irreverent her tone may be—for example, when she explains that given the bureaucratic hurdles of tissue donation, it is closer to UPS than to The Jeffrey Dahmer Story—it is easy to appreciate her respect for the people involved in her stories. The reader witnesses the pain of wearing a prosthetic leg, the struggle to breathe, and the demand for dignified recognition during National Ostomy Awareness Day. She extends the same admiration, respect, and gratitude to the researchers who allow her into their labs or clinics to report on scientific advances that remain inaccessible to most people.
While the book presents in-depth research on existing literature and the history of a topic, what makes Roach’s writing unique is the extent to which she engages in what one might call embodied inquiry. She travels to Chengdu, China, to visit the ClonOrgan lab, where genetically altered pigs are raised for xenotransplantation. She follows Orbis International to Mongolia, where the organisation provides cataract lenses to the nomadic communities. She heads to Scottsdale’s Eldorado Park to witness the Arizona ostomy 5K race. She also experiences the intubation of a dummy in a simulation lab, places herself inside a 1950s iron lung once used by a polio survivor and even attempts to have follicular units from her own head implanted into her leg. Her curiosity and willingness to experience and learn as much as possible seem limitless.
Replaceable You offers an incredible amount of information on a wide variety of topics, some of which can be fairly disturbing. In the interview with Preston, Roach declared that she cannot be grossed out (Harvard Science Book Talks and Research Lectures 2025, 16:01). That is a great advantage for the kind of research she conducts and for readers, who can learn about processes most would not want to experience firsthand. However, there are moments in the reading when she hints at ethical issues that one might want to discuss in greater detail. For example, when writing about the creation of chimeric organs in pigs using human pluripotent stem cells, she mentions questions raised by ethicists who worry about human brain cells entering a pig’s nervous system. The researcher replies that, as a precaution, embryos could be engineered to lack genes essential to neural cells, and she wonders what new complication that would create, but then moves on to the next issue. Entering into the philosophical aspects of the ways humanity alters nature would require a different kind of book.
In her introduction, Roach warns her readers, quoting a surgeon she interviewed: “I don’t think you can replace the human body.” She returns to acknowledge this basic fact in her last chapter: science has developed incredible techniques to replace parts and functions of our bodies. These sometimes come close to working as acceptable substitutes and might get better with time, but nothing can really do what human bodies—at least healthy and fully able human bodies—can do in the first place. Those of us whose bodies need assistance for basic functions have to accept our condition of clanking cyborgs.
About the author
Margarita Saona teaches at the Department of Hispanic and Italian Studies at the University of Illinois Chicago. Her work focuses on issues of gender, identity, memory, and illness in literature and the visual arts. Among her publications are Memory Matters in Transitional Peru (Palgrave, 2014) and De monstruos y cíborgs (Pandora Lobo Estepario, 2024).
References
Clynes, Manfred and Nathan S. Kline. 1960. Cyborgs in Space. Astronautics, 26–27: 74–75.
Roach, Mary. 2025. Replaceable You: Adventures in Human Anatomy. New York: W.W. Norton & Company.
“Mary Roach, in Conversation with Elizabeth Preston, “Replaceable You: Adventures in Human Anatomy.” Harvard Science Book Talks and Research Lectures. October 31, 2025. Video, https://youtu.be/6FUVkG8kieI?si=pdxXiFVo_AZkPD2u
