Life, Death, and the Problem of Biological Definition
Life, death, and the problem of biological definition examine one of the most difficult questions in biology: what distinguishes living systems from nonliving matter, what counts as death in organisms and cells, and why biological definition becomes unstable at the margins of viruses, dormancy, reproduction, and evolutionary change. This article explores how biology has tried to define life through organization, metabolism, responsiveness, reproduction, heredity, and the capacity for evolution, while also showing why no single checklist fully resolves the problem. It also considers the scientific significance of borderline cases such as viruses, dormant seeds, spores, and metabolically reduced organisms, showing why the meaning of life matters for biology, medicine, bioethics, origin-of-life research, and astrobiology.









