non-Hamitic Chadic based on which languages possessed gender. On the other hand, the classification relied on anthropological and racial features, such as skin color, hair type, and lifestyle. In the end, Meinhof's classification included languages from every family in Africa that is recognized by modern linguistics. Meinhof's version of the "Hamitic theory" remained prevalent until the 1940s, when it was definitively disproved by Joseph Greenberg. Earlier, the first scholar to question to existence of "Hamitic languages" was Marcel Cohen (1924), while skepticism was also expressed by A. Klingenheben and Dietrich Westermann (1920s and '30s). Greenberg rejected the Afroasiatic classification of languages that Meinhof had classified as "Hamitic" based on racial and anthropological data. Greenberg also proposed that Hausa was part of a Chadic branch of Afroasiatic, and that Afroasiatic consisted of five main branches, Berber, Chadic, Cushitic, Egyptian, and Semitic. The reluctance of some scholars to recognize Chadic as a member of Afroasiatic persisted as late as the 1980s. In 1969, Harold Fleming proposed that a group of languages classified as Cushitic by Greenberg were in fact an independent "Omotic" language family, a proposal that has been widely accepted but remains controversial. These five or six branches remain the academic consensus on the family. Origins Dating of Proto-Afroasiatic There is no consensus on when Proto-Afroasiatic was spoken. The latest possible date for the existence of Proto-Afroasiatic is c. 4000 BCE, after which Egyptian and the Semitic languages are first attested; however, the languages must have diverged and evolved for some time before this. Consequently, scholars have offered estimates for when Proto-Afroasiatic was spoken that range between 18,000 and 8,000 BCE. Tom Güldemann, however, argues that less time may have been required than is commonly assumed, as it is possible for a language to rapidly restructure due to language contact, as happened in the Chadic branch and probably also in Omotic. The Proto-Afroasiatic Homeland There is no consensus where the original homeland (Urheimat) of the first Afroasiatic speakers was located. Scholars have proposed locations both in the Middle East and in Africa. Roger Blench writes that the debate has "a strong ideological flavor", with associations between an Asian origin and "high civilization". An additional complicating factor is the lack of agreement on the subgroupings of Afroasiatic (see Subgrouping) - this makes associating archaeological evidence with the spread of Afroasiatic particularly difficult. An African origin has broad scholarly support, and is favored