Genetic evidence for a recent origin by hybridization of red wolves

Genetic data suggest that red wolves (Canis rufus) resulted from a hybridiz ation between coyotes (C. latrans) and grey wolves (C. lupus). The date of the hybridization, however, is uncertain. According to one hypothesis, the two species came into contact as coyotes increased their geographical range in conjunction with the advance of European settlers and as grey wolves we re extirpated from the American south. Alternatively, the red wolves could have originated tens of thousands of years ago as a result of climate and h abitat changes that disturbed the ecology of the two parent species. To obt ain an upper limit on the date of hybridization that would help to distingu ish the two scenarios, we compared microsatellite allele length distributio ns from red wolves, coyotes and grey wolves. Subject to the assumptions of our analysis, we conclude that the red wolves result of hybridizations that occurred during the past 12 800 years, and probably during the past 2500 y ears.