May still require allopatry to keep hybrids from being diluted out.
From the scienceblogs.com
Allopatry has also been proposed as the mechanism of speciation in Dioon, which predominantly occurs in Mexico.
From the en.wikipedia.org
There are no documented cases of sympatric speciation in cycads and allopatry appears to be the most common form of speciation in the group.
From the en.wikipedia.org
Due to its well-defined allopatry and because it is much larger and heavier than its relatives, it has been reclassified as a separate species.
From the en.wikipedia.org
Sympatric speciation does not imply secondary contact, which is speciation or divergence in allopatry followed by range expansions leading to an area of sympatry.
From the en.wikipedia.org
Allopatric and allopatry are terms from biogeography, referring to organisms whose ranges are entirely separate such that they do not occur in any one place together.