evolution

[ ev-uh-loo-shuhnor, especially British, ee-vuh- ]

noun

1. any process of formation or growth; development:

   the evolution of a language; the evolution of the airplane.

   Synonyms: metamorphosis, progression, change

   Antonyms: changelessness, inactivity, stasis

2. a product of such development; something evolved:

   The exploration of space is the evolution of decades of research.

3. Biology. change in the gene pool of a population from generation to generation by such processes as mutation, natural selection, and genetic drift.
4. a process of gradual, peaceful, progressive change or development, as in social or economic structure or institutions.
5. a motion incomplete in itself, but combining with coordinated motions to produce a single action, as in a machine.
6. a pattern formed by or as if by a series of movements:

   the evolutions of a figure skater.

7. an evolving or giving off of gas, heat, etc.
8. Mathematics. the extraction of a root from a quantity. Compare involution ( def 4 ).
9. a movement or one of a series of movements of troops, ships, etc., as for disposition in order of battle or in line on parade.
10. any similar movement, especially in close order drill.

evolution

/ ˌiːvəˈluːʃən /

noun

1. biology a gradual change in the characteristics of a population of animals or plants over successive generations: accounts for the origin of existing species from ancestors unlike them See also natural selection
2. a gradual development, esp to a more complex form

   the evolution of modern art

3. the act of throwing off, as heat, gas, vapour, etc
4. a pattern formed by a series of movements or something similar
5. an algebraic operation in which the root of a number, expression, etc, is extracted Compare involution
6. military an exercise carried out in accordance with a set procedure or plan

evolution

/ ĕv′ə-lo̅o̅′shən /

1. The process by which species of organisms arise from earlier life forms and undergo change over time through natural selection . The modern understanding of the origins of species is based on the theories of Charles Darwin combined with a modern knowledge of genetics based on the work of Gregor Mendel. Darwin observed there is a certain amount of variation of traits or characteristics among the different individuals belonging to a population. Some of these traits confer fitness—they allow the individual organism that possesses them to survive in their environment better than other individuals who do not possess them and to leave more offspring. The offspring then inherit the beneficial traits, and over time the adaptive trait spreads through the population. In twentieth century, the development of the the science of genetics helped explain the origin of the variation of the traits between individual organisms and the way in which they are passed from generation to generation. This basic model of evolution has since been further refined, and the role of genetic drift and sexual selection in the evolution of populations has been recognized.
2. See also natural selectionSee Notes at adaptation
3. A process of development and change from one state to another, as of the universe in its development through time.

evolution

1. A theory first proposed in the nineteenth century by Charles Darwin , according to which the Earth 's species have changed and diversified through time under the influence of natural selection . Life on Earth is thought to have evolved in three stages. First came chemical evolution , in which organic molecules (see also organic molecule ) were formed. This was followed by the development of single cells capable of reproducing themselves. This stage led to the development of complex organisms capable of sexual reproduction . Evolution is generally accepted as fact by scientists today, although debates continue over the precise mechanisms involved in the process. ( See mutation , punctuated equilibrium , and creation science .)

Notes

The first cell is thought to have been formed when the Earth was less than a billion years old.

Derived Forms

• ˌevoˈlutionary, adjective

Other Words From

• evo·lution·al adjective
• evo·lution·al·ly adverb
• anti·evo·lution adjective
• anti·evo·lution·al adjective
• anti·evo·lution·al·ly adverb
• de-ev·o·lution noun
• nonev·o·lution·al adjective
• nonev·o·lution·al·ly adverb
• preev·o·lution·al adjective
• proev·o·lution adjective
• unev·o·lution·al adjective

Word History and Origins

Origin of evolution¹

First recorded in 1615–25; from Latin ēvolūtiōn- (stem of ēvolūtiō ) “an unrolling, opening,” equivalent to ēvolūt(us) past participle of ēvolere “to roll out or away” + -iōn-; evolute, -ion

Word History and Origins

Origin of evolution¹

C17: from Latin ēvolūtiō an unrolling, from ēvolvere to evolve

A Closer Look

Darwin's theory of evolution by natural selection assumed that tiny adaptations occur in organisms constantly over millions of years. Gradually, a new species develops that is distinct from its ancestors. In the 1970s, however, biologists Niles Eldredge and Stephen Jay Gould proposed that evolution by natural selection may not have been such a smooth and consistent process. Based on fossils from around the world that showed the abrupt appearance of new species, Eldredge and Gould suggested that evolution is better described through punctuated equilibrium. That is, for long periods of time species remain virtually unchanged, not even gradually adapting. They are in equilibrium, in balance with the environment. But when confronted with environmental challenges—sudden climate change, for example—organisms adapt quite quickly, perhaps in only a few thousand years. These active periods are punctuations, after which a new equilibrium exists and species remain stable until the next punctuation.

Example Sentences

Scientists have struggled to understand how stars spiraling together during this critical period affects the stars' subsequent evolution.

From Science Daily

This evolution was punctuated around 30 million years ago with the emergence of a newer, better way to photosynthesize.

From Science Daily

"But evolution acts on all parts of the body, great and small. Structures and regions that have been ignored are often gold mines for new insights and untold tales."

From Science Daily

Vultures are perfectly adapted by millions of years of evolution to detect carcasses across vast landscapes quickly and reliably.

From Science Daily

"With this new information, we can better reconstruct the last 1,500 years of horse breeding history and evolution."

From Science Daily

Related Words

• change
• enlargement
• expansion
• growth
• progression
• transformation