The most recent taxonomic revision of the Aspidoscelis hyperythra complex (Grismer, 1999) used the operationalism of diagnosable allopatric populations
to elevate five insular populations, recognized as subspecies by Walker and Taylor (1968), to species rank.
Here, we focus on molecular species diagnosis, inferences about the abundance and distribution of oyster species in the northern Ariake Sea, and gamete incompatibility between sympatric and allopatric populations
of the Kumamoto and Pacific oysters, C.
Although there are two allopatric populations
, no subspecies are recognized.
Reproductive strategies and the evolution of viviparity in two allopatric populations
of the Mexican lizard, Sceloporus aeneus.
We explored the patterns of geographic variation in the fine structural characteristics of the song of five subspecies of Common Bush Tanagers from Mesoamerica, and discuss whether song variation resembles allopatric populations
and patterns of genetic variation reported in previous studies (Bonaccorso et al.
Guideline 6: To avoid declines in population fitness caused by outbreeding depression, allopatric populations
that qualify as evolutionarily significant units (ESUs), subspecies, or closely related species should not be mixed.
Reinforcement of incompatibilities by selection in sympatry (Servedio and Noor 2003) should lead to a faster reduction of interbreeding in sympatric than in largely allopatric populations
It is not clear whether the difference in song would constitute a behavioral barrier to gene flow upon secondary contact among these currently allopatric populations