Evolutionary

Evolutionary is an adjective relating to evolution, the process by which populations of organisms change over many generations through heritable variation and differential reproduction. In biology, evolutionary theory explains how biodiversity arises from ancestral forms by descent with modification.

Modern understanding combines Darwinian natural selection with genetics, showing how mutation, recombination, and gene flow generate variation, and how environmental pressures shift allele frequencies over time. The core mechanisms include natural selection, genetic drift, mutation, and gene flow; these interact with population structure to produce adaptation and, ultimately, speciation. Descent with modification and common ancestry describe the pattern of relatedness among living groups.

Evidence for evolution comes from multiple lines: the fossil record, comparative anatomy and embryology, biogeography, and molecular genetics. The concept of a shared ancestry implies trees of life, with branching patterns inferred by phylogenetics. Timescales span billions of years, with life beginning in the distant past, multicellular life appearing hundreds of millions of years ago, and the human lineage diverging from other primates in the recent past.

The term is used to convey processes that shape diversity rather than purpose. Misconceptions persist that evolution implies progress toward perfection or foresight. In addition to biology, the word appears in evo-devo, population genetics, and phylogenetics, and in computer science as evolutionary algorithms that mimic selection to optimize problems. Evolutionary theory remains a central framework for understanding life and its history.