Also found in: Medical, Encyclopedia, Wikipedia.
The division of a widespread group of organisms by a geographic barrier, such as a mountain range or a body of water, often resulting in the evolution of related species on either side of the barrier.
[Latin vicārius, substitute (since after a vicariant speciation event, one species can be thought of as "substituting for" a related species on the other side of the geographic barrier); see vicarious + -ance.]
vi·car′i·ant adj. & n.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
(Biology) any of several closely related species, races, etc, each of which exists in a separate geographical area: assumed to have originated from a single population that became dispersed by geological events
[C20: from Latin vicārius (see vicar) + -ant]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014