Germ-soma separation

Germ-soma separation is the division of labor between reproductive cells (germ line) and non-reproductive cells (soma) that characterizes most multicellular organisms. It is the primary mechanism by which multicellular systems suppress within-group conflict and maintain themselves as coherent units of selection.\n\nWithout germ-soma separation, every cell is a potential competitor, with an evolutionary incentive to maximize its own replication at the expense of the collective. The separation aligns the fitness interests of the cells with the fitness of the organism by restricting reproduction to a specialized lineage. When this mechanism fails, the result is cancer: cells that resume individual replication and destroy the collective.\n\nThe germ-soma distinction is one of the major evolutionary transitions in the history of life. It transforms a group of competing cells into an organism with a unified reproductive fate. But the distinction is not absolute. Some organisms retain substantial regenerative capacity, and some colonial organisms blur the line between germ and soma. The separation is a gradient, not a binary. The evolutionary dynamics of cells that have escaped germ-soma constraints is the subject of somatic evolution.\n\n\n\n