noun, plural: vicariances
The separation of a large group of organisms from the population due to a geographic barrier.
The geologic event which produces geographic barrier, such as volcano, river, earthquake, etc.
Word origin: From vicariant, from Latin vicārius, vicarious, “substitute, deputy” (adj. and n.), from vicis “turn, change, exchange, substitution.
Related forms: vicariant (adjective), vicarious (adjective).
See also: vicariant speciation, allopatry.