Out of Africa I pp 67-85
Behavioral and Environmental Background to ‘Out-of-Africa I’ and the Arrival of Homo erectus in East Asia
Current evidence of hominin fossils and artifacts in China and Indonesia points to the arrival and persistence of the genus Homo in East Asia by 1.7 million years ago (Ma). By at least 1.66 Ma, East Asian hominins had spread across a wide range of biotic and climatic zones, spanning 7°S–40°N on the basis of well-constrained age data from the Nihewan and Yuanmou basins, China, and Sangiran, Indonesia. Archeological assemblages and fragmentary hominin morphology show strong similarities with African Oldowan hominin toolmakers and early Homo erectus, although the taxonomic status of the oldest known Asian hominins is not yet securely established. Despite this apparent derivation of East Asian from African hominins, an initial comparison of large mammal faunas offers little evidence of ‘fellow travelers’, i.e., a set of African mammalian species that co-dispersed with Homo to East Asia. We offer three hypotheses to account for the existing data: (1) unique hominin dispersal, in which no other African mammals were involved; (2) African fellow travelers, in which Homo and a small number of other mammals reached western Eurasia, yet hominins dispersed independently to more distant regions; and (3) relay dispersal, in which Homo always dispersed as part of an ecological community but in association with a different set of mammalian species from one region to another.