Evolutions

Evolutions refer to the processes by which populations change their heritable traits over successive generations. While the term is broad, it is most often used to describe biological evolution—the descent with modification of organisms from common ancestors. The plural form is used when discussing multiple instances, lineages, or kinds of evolutionary change, as well as evolution-like processes in culture, technology, and ecosystems.

Biological evolution arises from genetic variation, imperfect heredity, and differential survival and reproduction. Key mechanisms include natural selection, genetic drift, mutation, gene flow, and recombination. Sexual selection and coevolution with other species can shape populations as well. Over time, these forces produce changes in trait frequencies, the emergence of new species, and the adaptation of organisms to environments.

Evidence for evolution comes from the fossil record, comparative anatomy, embryology, biogeography, and molecular biology. Patterns observed include gradual change, punctuated equilibria, convergent and divergent evolution, and adaptive radiations. Evolution is not directed toward a goal; it acts on existing variation and depends on historical contingencies.

Historically, the concept emerged from early ideas about change over time and was synthesized with genetics in the 20th century to form the modern synthesis. Beyond biology, the term is also applied to cultural and technological evolutions, where ideas and artifacts spread and transform through replication and modification.