The Harifians are viewed as migrating out of the Fayyum[lower-alpha 3] and the Eastern Deserts of Egypt during the late Mesolithic to merge with the Pre-Pottery Neolithic B (PPNB)[lower-alpha 3] culture, whose tool assemblage resembles that of the Harifian. This assimilation led to the Circum-Arabian Nomadic Pastoral Complex, a group of cultures that invented nomadic pastoralism, and may have been the original culture which spread Proto-Semitic languages throughout Mesopotamia.[19]