A simplified diagram of the process of allopatric speciation (vicariance). A species population becomes separated by a geographic barrier, whereby reproductive isolation evolves producing two separate species.
<a href="//commons.wikimedia.org/wiki/User:Azcolvin429" title="User:Azcolvin429">Andrew Z. Colvin</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>