adjective
Biology1Of species, populations, features, etc.: existing or arising at different periods of geological time.
2Of speciation: occurring as a result of the development of different breeding seasons in populations which are not geographically separated; (of organisms) breeding or flourishing at different seasons.
Origin
1940s; earliest use found in Ernst Mayr (1904–2005), evolutionary biologist. From allo- + -chronic.
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