 The only other gene an Olduvai domain has been found in is mammalian myomegalin, believed to be the origin of the "NBPF" genes via duplication.Myomegalin itself arose from a duplication of "CDK5RAP2", and all of these genes have been implicated in the development of neurons.Olduvai copy number is the highest in humans (~289, with person-to-person variations), reduced in African great apes (~125 copies in chimpanzees, ~99 in gorillas, ~92 in orangutans), further reduced in Old World monkeys (~35), single- or low-copy in non-primate mammals and absent in non-mammals.