Hybridization Helps Colonizers Become Conquerors

Species colonizing new environments face an uphill battle to become established. Because colonizing populations are often small, opportunities for sexual reproduction may be limited by availability of mates or viable pollen—an example of an Allee effect (1, 2). The presence of a more abundant related species with similar climatic, habitat, and nutritional needs can further reduce the odds of colonizer establishment (3, 4). Despite these hurdles, there are numerous examples of colonizing species increasing in number and range to the detriment of the recipient ecological and human communities. The field of invasion biology studies such species to further our understanding of the fundamental mechanisms that allow colonizing species to prosper (5), as well as the more applied goals of predicting, preventing, and controlling invasions (6). Mesgaran et al.’s study (7) contributes to these goals by illustrating how colonizing species can exploit the presence of congeners to overcome the problems associated with low numbers through hybridization and the subsequent reemergence of colonizer genotypes.