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Condensed matter studies have shown that fusion of two lipid membranes requires drastic structural rearrangements and is thus intrinsically slow. Interestingly, all forms of life on Earth use fusion to carry out some of the most fundamental life processes—communication, growth, metabolic homeostasis—that must be accomplished on timescales as short as a fraction of a millisecond. How do living systems beat the prohibitively slow speed limit imposed by membrane fusion? How do they tune the fusion timescale so that it matches a particular biological function? Here it is argued that fusion-mediated life processes as diverse as viral infection, muscle growth, and neuronal communication have all evolved at a common strategy that can be captured through a unifying relationship between the timescale of the process and the strength of the relevant trigger. Activated motion in a bias field along an emergent collective coordinate provides a suitable physical picture. The timescale is set by a reduced quantity defined as the trigger strength in the active state scaled by a system-specific critical parameter. The unified description suggests simple physical principles that organize the complexity of living systems and evolutionarily drive them toward functional behavior.