Hugin & Munin Journal

In Lois McMaster Bujold’s Vorkosigan novels, the uterine replicator—an artificial womb capable of sustaining fetal development outside the human body—does more than spare women the physical work and risk of pregnancy. It removes gestation from the evolutionary arrangement that produced the human newborn: large-brained by primate standards, physically helpless and still at the beginning of an unusually long period of neural development. Caesarean delivery already allows some infants to bypass the dimensions of the birth canal. Complete artificial gestation would go further. It would remove fetal development from the pregnant body, loosening not only the mechanical problem of delivery but some of the placental, metabolic and physiological constraints that shape growth before birth. The obvious speculation follows quickly. Without a pelvis to pass through, could babies develop larger heads and brains? Could gestation continue for twelve or sixteen months? Combined with embryo selectio...

Medicine cannot remove human functions simply to discover which ones matter. Nature, disease and accident nevertheless produce cases that resemble experiments in subtraction. Some people carry damaging variants in both copies of a gene. Others develop without an organ, lose one through disease or surgery, or survive injuries that remove substantial parts of the body. Modern medicine creates another category by transferring biological work to drugs, prostheses and machines. These cases offer an empirical route into the question of what a human system actually requires. But survival is an ambiguous result. A person who lives without a structure has not necessarily shown that it was useless. Another pathway may have absorbed its work, development may have reorganised around its absence, or medicine may be supplying enough of the missing function to keep the larger system operating. The cost may also remain hidden until infection, injury, pregnancy, ageing or some other form of stres...

Modern medicine can remove a patient’s T cells, engineer them in a laboratory and return them with receptors designed to recognise cancer . It can transplant healthy blood-forming stem cells and reprogramme mature cells into an embryonic-like pluripotent state. Yet it often struggles to predict how any one intervention will behave inside the changing ecology of an individual body. That gap between intervention and understanding is the most compelling subject of Siddhartha Mukherjee’s The Song of the Cell . The book follows the history of cell biology from the first microscopes and early theories of disease to immunotherapy, reproductive medicine and regenerative treatments. Its deeper concern is the unstable distance between seeing a biological phenomenon, explaining it and learning to control it. Medicine has repeatedly acquired the power to alter cellular behaviour before it fully understood what that behaviour meant within the larger organism. Sometimes that asymmetry saves live...