[The concept of "species--ecological mates" and some obscure points in the evolution of the family of hominids].

Species-ecological twins are the related species that inhabit the same habitats. Both micro- and macroevolution proceeds faster in a system with two such species than in a single species. The hypothesis that evolution of hominids was accelerated by the existence of twin species has been proposed. Species of the Australopithecus genus were twin species for Homo habilis and H. erectus. Both paleontological and cryptozoological data indicate that H. sapiens also has a complimentary species. Small population of the twin species may still exist in obscure parts of the Earth.