• synonyms


[mahy-kroh-ev-uh-loo-shuh n or, esp. British, -ee-vuh-]
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noun Biology.
  1. evolutionary change involving the gradual accumulation of mutations leading to new varieties within a species.
  2. minor evolutionary change observed over a short period of time.

Origin of microevolution

First recorded in 1935–40; micro- + evolution
Related formsmi·cro·ev·o·lu·tion·ar·y, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for microevolution

Contemporary Examples

microevolution in Medicine


(mī′krō-ĕv′ə-lōōshən, -ē′və-)
  1. Evolution resulting from a succession of relatively small genetic variations that often cause the formation of new subspecies.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

microevolution in Science


  1. Evolutionary change below the level of the species, resulting from relatively small genetic variations. Microevolution produces new strains of microorganisms, for example, or the rise of a new subspecies. The accumulation of many microevolutionary changes results in macroevolution.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.