evolution

noun evo·lu·tion \ ˌe-və-ˈlü-shən , ˌē-və- \

|Updated on: 19 Jul 2018

Definition of evolution

1 a : descent with modification from preexisting species : cumulative inherited change in a population of organisms through time leading to the appearance of new forms : the process by which new species or populations of living things develop from preexisting forms through successive generations

Evolution is a process of continuous branching and diversification from common trunks. This pattern of irreversible separation gives life's history its basic directionality.
—Stephen Jay Gould

also : the scientific theory explaining the appearance of new species and varieties through the action of various biological mechanisms (such as natural selection, genetic mutation or drift, and hybridization)

Since 1950, developments in molecular biology have had a growing influence on the theory of evolution.
—Nature

In Darwinian evolution, the basic mechanism is genetic mutation, followed by selection of the organisms most likely to survive.
—Pamela Weintraub

b : the historical development of a biological group (such as a race or species) : phylogeny

2 a : a process of change in a certain direction : unfolding

b : the action or an instance of forming and giving something off : emission

c (1) : a process of continuous change from a lower, simpler, or worse to a higher, more complex, or better state : growth

(2) : a process of gradual and relatively peaceful social, political, and economic advance

d : something evolved

3 : the process of working out or developing

4 : the extraction of a mathematical root

5 : a process in which the whole universe is a progression of interrelated phenomena

6 : one of a set of prescribed movements

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evolutionarily

play \ˌe-və-ˈlü-shə-ˌner-ə-lē, ˌē-və-\ adverb

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evolutionary

play \ˌe-və-ˈlü-shə-ˌner-ē, ˌē-və-\ adjective

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evolutionism

play \ˌe-və-ˈlü-shə-ˌni-zəm, ˌē-və-\ noun

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evolutionist

play \ˌe-və-ˈlü-sh(ə-)nist, ˌē-və-\ noun or adjective

See evolution defined for English-language learners

See evolution defined for kids

Examples of evolution in a Sentence

changes brought about by evolution
an important step in the evolution of computers

Recent Examples of evolution from the Web

The new findings don’t exactly rewrite the story of human hand evolution.

— meilan solly, Smithsonian, "Did the Human Hand Evolve as a Lean Mean Bone-Smashing Machine?," 13 July 2018
Her nomination showed that voters paid attention to the show’s evolution.

— glenn whipp, latimes.com, "Emmy snubs and surprises: New faces are in, old institutions are out and Sandra Oh makes history," 12 July 2018
After the Scopes trial, Oregon leaders, ever pragmatic, changed their strategy to campaign to have creationism taught alongside evolution.

— Longreads, "Oregon’s Racist Past," 12 July 2018
Shai Gilgeous-Alexander, Clippers Gilgeous-Alexander’s steady evolution into a high-level playmaker has quietly been a fascinating storyline over the last nine months.

— jeremy woo, SI.com, "Rookie Report Cards: The Most Noteworthy Summer League Showings," 11 July 2018
Still, despite Casey’s displaying some – your choice – backsliding or evolution on the issue, political science professor Thomas Baldino, at Wilkes University in Casey’s home region, thinks the senator will be fine.

— john baer, Philly.com, "Casey's opposition to Trump SCOTUS pick raises questions about Casey's abortion stance | John Baer," 10 July 2018
Although some people may appear more playful than others, researchers say that we are all wired by evolution to play.

— jennifer wallace, courant.com, "Play Is Important For Adults, Too," 9 July 2018
Sessions reversed those years of legal evolution with his ruling in A-B-.

— henry gass, The Christian Science Monitor, "With 'zero tolerance,' new strain on already struggling immigration courts," 9 July 2018
Those dogs then spent thousands of isolated evolution on the continent.

— josh magness, miamiherald, "Europeans arrived — and America's native dogs disappeared. They left something behind," 6 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'evolution.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of evolution

Latin evolution-, evolutio unrolling, from evolvere

NEW! Time Traveler

First Known Use: 1616

in the meaning defined at sense 6

See Words from the same year

evolution Synonyms

EVOLUTION Defined for Kids

evolution

noun evo·lu·tion \ ˌe-və-ˈlü-shən , ˌē-və- \

Definition of evolution for Students

1 : the theory that the various kinds of existing animals and plants have come from kinds that existed in the past

2 : the process of development of an animal or a plant

Medical Dictionary

evolution

noun evo·lu·tion \ ˌev-ə-ˈlü-shən also ˌē-və- \

medical Definition of evolution

1 : a process of change in a certain direction

tumor evolution and progression
—I. J. Fidler et al

2 a : the historical development of a biological group (as a race or species) : phylogeny

b : a theory that the various types of animals and plants have their origin in other preexisting types and that the distinguishable differences are due to modifications in successive generations

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