Natural selection is the mechanism by which heritable trait variants that confer higher probability of survival and reproduction increase in frequency within a population across generations, while variants that lower that probability decrease. It operates only on genetically transmissible variation, acts on populations rather than individuals, and produces measurable change as a shift in trait frequency over generational time — the differential-reproduction logic that makes it the principal driver of evolution. The concept belongs to evolutionary biology within the broader biological sciences and supplies the causal engine underlying descent with modification, adaptation, and population genetics.
Natural selection is the mechanism by which heritable trait variants that confer higher probability of survival and reproduction increase in frequency within a population across generations, while va…