Dispersal Of Homo Erectus Research Articles

Venturing out safely: The biogeography of Homo erectus dispersal out of Africa

The dispersal of Homo erectus out of Africa at some 1.9 million years ago is one of the most important, crucial, and yet controversial events in human evolution. Current opinions about this episode expose the contrast between those who see H. erectus as a highly social, cooperative species seeking out new ecological opportunities to exploit, and those preferring a passive, climate driven explanation for such an event. By using geostatistics techniques and probabilistic models, we characterised the ecological context of H. erectus dispersal, from its East African origin to the colonization of Eurasia, taking into account both the presence of other large mammals and the physical characteristics of the landscape as potential factors. Our model indicated that H. erectus followed almost passively the large herbivore fauna during its dispersal. In Africa, the dispersal was statistically associated with the presence of large freshwater bodies (Rift Valley Lakes). In Eurasia, the presence of H. erectus was associated with the occurrence of geological outcrops likely yielding unconsolidated flint. During the early phase of dispersal, our model indicated that H. erectus actively avoided areas densely populated by large carnivores. This pattern weakened as H. erectus dispersed over Europe, possibly because of the decreasing presence of carnivores there plus the later acquisition of Acheulean technology. During this later phase, H. erectus was associated with limestone and shaley marl, and seems to have been selecting for high-elevation sites. While our results do not directly contradict the idea that H. erectus may have been an active hunter, they clearly point to the fact that predator avoidance may have conditioned its long-distance diffusion as it moved outside Africa. The modelled dispersal route suggests that H. erectus remained preferentially associated with low/middle latitude (i.e., comparatively warm) sites throughout its colonization history.

Ecosystem variability and early human habitats in eastern Africa

The role of savannas during the course of early human evolution has been debated for nearly a century, in part because of difficulties in characterizing local ecosystems from fossil and sediment records. Here, we present high-resolution lipid biomarker and isotopic signatures for organic matter preserved in lake sediments at Olduvai Gorge during a key juncture in human evolution about 2.0 Ma--the emergence and dispersal of Homo erectus (sensu lato). Using published data for modern plants and soils, we construct a framework for ecological interpretations of stable carbon-isotope compositions (expressed as δ(13)C values) of lipid biomarkers from ancient plants. Within this framework, δ(13)C values for sedimentary leaf lipids and total organic carbon from Olduvai Gorge indicate recurrent ecosystem variations, where open C(4) grasslands abruptly transitioned to closed C(3) forests within several hundreds to thousands of years. Carbon-isotopic signatures correlate most strongly with Earth's orbital geometry (precession), and tropical sea-surface temperatures are significant secondary predictors in partial regression analyses. The scale and pace of repeated ecosystem variations at Olduvai Gorge contrast with long-held views of directional or stepwise aridification and grassland expansion in eastern Africa during the early Pleistocene and provide a local perspective on environmental hypotheses of human evolution.

Evolution and Environmental Change in Early Human Prehistory

Understanding the interaction between past environmental and evolutionary change informs scientific and public awareness about natural environmental dynamics. Evidence of dramatic climate variability, cooling, and aridity over the past six million years has stimulated research about whether environmental change has been a major causal factor in the development of our species' defining characteristics. Examples pertaining to the evolution of bipedality, earliest known toolmaking, dispersal of Homo erectus, extinction of Neanderthals, and the global spread H. sapiens all point to the emergence of adaptability in response to environmental uncertainty as a recurrent theme in human evolution. A synthesis of African paleoclimate data suggests that significant events in human origins tended to occur during lengthy eras of strong climate fluctuation. Human adaptability will continue to be tested as societies face the challenges of adjusting to unprecedented change in Earth's environmental dynamics.

Out of Africa 1: Who, where, and when?

Out of Africa 1: Who, where, and when?

The Dispersal of Homo erectus from Africa and the Emergence of More Modern Humans

The earliest traces of Homo erectus have been uncovered in eastern Africa, where fossils from the Turkana basin are 1.7 to 1.8 million years in age. Later members of this species reached other parts of the continent, and probably Homo erectus had begun to disperse out of Africa before 1.0 million years ago. One route would have taken archaic people around the eastern Mediterranean, to Europe and southwestern Asia. Assemblages of crude stone tools are found in Europe, although no human bones are known from these Early Pleistocene localities. The spread of Homo erectus eastward into Asia is poorly documented, but it is clear that populations were present in Java at an early date, and the famous caves at Zhoukoudian were inhabited nearly 0.5 million years ago. Throughout this long history, the species seems to have remained stable morphologically. There are few indications of change, and evolutionary continuity with later groups is not readily apparent. Anatomically more advanced fossils from sites in Europe...

Pleistocene connexions between Africa and Southwest Asia: an archaeological perspective

This paper investigates the archaeological evidence for direct prehistoric connexions between Southwest Asia and Africa during the Palaeolithic period. The importance of the ‘Levantine Corridor’ bridging the two continents is stressed in describing the dispersal ofHomo erectus. The continental bridge could have been through the Nile Valley during the Late Acheulian and the emergence of earlyHomo sapiens. Upper Palaeolithic and especially Epi-Palaeolithic dispersal during the terminal Pleistocene are discussed. The role of Egyptian-Levantine connexions in the context of the complex situation which led to sedentism is stressed.