Science writer Mary Roach is fascinated by the human body, especially, she says, the “gooey bits and pieces of us that are performing miracles on a daily basis.”
Take the human heart, for instance. If we are lucky, Roach says, our hearts might continue beating for 80+ years. “What thing that you buy at Best Buy keeps going that long?” she asks.
Roach is known for her books about what makes the human body so remarkable. She is done deep dives on human cadavers, the digestive system, and the science of sex. Now, in Replaceable You: Adventures in Human Anatomy, she chronicles both the history of body part replacement (including prosthetic noses that date back to the 1500s), as well as more recent medical breakthroughs.
The book was inspired by a woman Roach knows with spina bifida, whose gait was impeded by a twisted foot. The woman was seeking to have her foot surgically amputated and replaced with a prosthetic limb, when she encountered an unexpected impediment: Surgeons were reluctant to remove what they considered a healthy limb — even though the patient could not walk on it. “And I thought that was interesting, the reluctance of the surgeons to remove a foot because it is an act with some finality to remove a foot,” Roach says.
Roach’s book describes how advancements in gene editing and 3D printing technology might further make our anatomy “replaceable.” She profiles scientists in lab at Carnegie Mellon University who used a 3D printer to create a tiny ventricle, which was used to pump the heart of a mouse. However, she adds, the Trump Administration’s cuts to medical research threaten to interrupt the “pipeline of innovation and discovery.”
“That’s going to have terrible effects further down the line,” Roach says. “Just looking forward to the future of innovation and medical care, it’s very depressing.”
REFERENCE: National Public Radio (NPR); 16 SEP 2025; Terry Gross