INTERGENERIC HYBRID BABOONS

Though belonging to genera that have been distinct for several million years, gelada and common baboons-Theropithecus gelada and Papio hamad ryas sensu lato, respectively-interbreed occasionally, even in the wil d. A female hamadryas at Bihere Tsige Park, Addis Ababa, Ethiopia, app arently favored a gelada male over eligible conspecifics and produced several offspring with him. The F-1 hybrids were large but development ally normal. In skull and tooth form, and to a lesser extent in postcr anial proportions, they were intermediate between the parental forms b ut lacked most of their parents' derived, (sub)species-specific epigam ic characters. A female infant born to a subadult F-1 was sired by a h amadryas. The backcross infant appeared normal and was still flourishi ng at about 2.5 years. Though perhaps impeded by natural selection aga inst poorly adapted hybrids, theoretically interspecific hybridization could exceed mutation as a source of novel, preadapted genes in the w ild.