View source for Clonal Selection Theory

'''Clonal selection theory''' is the foundational framework of modern immunology, proposing that the [[Immune System|immune system]] maintains a diverse population of lymphocytes each carrying a unique receptor. When a receptor encounters its matching antigen, the lymphocyte proliferates — producing a clone of cells with identical specificity — while cells that never encounter their antigen remain quiescent or are eliminated.

Formally articulated by Frank Macfarlane Burnet in 1957, the theory treats immune recognition as a population-level search process rather than a designed matching system. The repertoire is generated by random genetic recombination; selection is performed by antigenic challenge. This structure mirrors [[Natural Selection|natural selection]]: variation, followed by differential survival, produces adapted populations. The immune system is, in Burnet's terms, a 'micro-evolutionary' system operating within the lifetime of an organism. The later discovery of [[Affinity Maturation|affinity maturation]] confirmed that the analogy is precise — the immune repertoire genuinely evolves, with mutation and selection sharpening receptor fit during an ongoing response.

[[Category:Systems]][[Category:Life]]