evolution

Pronunciation key ( ev′ə-l′shən ) ( ev′ʼl-ū′shən )

ev•o•lu•tion

n.

[L. evolutio, an unrolling or opening < evolutus, pp. of evolvere; see EVOLVE].

1. An unfolding, opening outward or working out; developmental process, formation or growth.
2. A resulting product of evolution. The thing that has evolved.
• a movement which is part of a pattern or series.
• a pattern which is produced or seems to be produced by a series of movements such as the evolutions of a professional skater.
3. Biology.
   • Development of a species, organism or organ derived from a rudimentary or earlier state to its present and more complete form; phylogeny or ontogeny.
   • An obsolete theory which held the germ cell contains a fully developed individual in miniature form; theory of preformation.
   • Now generally accepted theory that all species derived from earlier forms of common ancestors, by hereditary transmission of slight variations in successive generations. See Darwinian Theory, Lamarckism, Mutation, Natural Selection.
4. Mathematics.
   • Extraction of a root from a given power: opposed to involution.
   • Development of a curve of which an involute can form.

5. Military and Navy
• Various maneuvers or movements by which ships and men change formation.

References

Webster's New World Dictionary of the American Language (College Edition) ©1955