Intergeneric hybrid baboons

Though belonging to genera that have been distinct for several million years, gelada and common baboons - Theropithecus gelada and Papio hamadryas sensu lato, respectively - interbreed occasionally, even in the wild. A female hamadryas at Bihere Tsige Park, Addis Ababa, Ethiopia, apparently favored a gelada male over eligible conspecifics and produced several offspring with him. The F₁ hybrids were large but developmentally normal. In skull and tooth form, and to a lesser extent in postcranial proportions, they were intermediate between the parental forms but lacked most of their parents' derived, (sub)species-specific epigamic characters. A female infant born to a subadult F₁ was sired by a hamadryas. The backcross infant appeared normal and was still flourishing at about 2.5 years. Though perhaps impeded by natural selection against poorly adapted hybrids, theoretically interspecific hybridization could exceed mutation as a source of novel, preadapted genes in the wild.