Hominid Dispersal Research Articles

Changes in climate extremes in Zambia during green and dry Sahara periods and their potential impacts on hominid dispersal

Northern Africa experienced humid periods known as African humid periods or Green Sahara periods during the late Pleistocene and Holocene. The waxing and waning of the African Monsoon over the last several million years raises the question of how the climatic variability in the African Saharan region could have influenced the evolution and dispersion of hominins in Africa. Little is yet known about the changes in climate extremes in central southern Africa associated with these cycles and their potential impacts on human migration. In this study, we use a regional climate model to simulate archetypal Green and Desert Sahara periods under high and low boreal summer insolation and investigate the resulting changes in climate variability and extremes in South Tropical Africa, with a focus on Zambia. Our results indicate drier and warmer conditions under Green Sahara conditions relative to the Dry Sahara periods. In particular, an increase in the length of droughts and higher temperature extremes have been simulated over the Zambian region in the Green Sahara experiment. Our results suggest that during the Dry Sahara periods, Zambia may have offered better environmental conditions for hominin populations than the Central African Plateau (CAP). In contrast, the Green Sahara periods offered opposite conditions, potentially encouraging hominins to disperse through the large river valleys into the CAP and northward into the Sahel and Sahara.

What is currently (un)known about the Chinese Acheulean, with implications for hypotheses on the earlier dispersal of hominids

Progress in research on the different handaxe-bearing regions of China is making study of the Acheulean a dynamic field in the Chinese Palaeolithic. Given the separate history of these developments, in this paper we integrate the latest achievements in the four key Acheulean regions in China (namely, Dingcun, Bose, Luonan and Danjiangkou Reservoir Region). Based on this, and combined with our own observations of materials from these four regions, we summarize what is currently known about the Chinese Acheulean and propose those questions that are still awaiting resolution. Finally, we consider five arguments that are highly relevant to the origins of the Acheulean techno-complex in China. From this synthesis, we suggest that the technological transmission hypothesis might be a suitable explanation for the emergence of Chinese handaxe technology, and we provide supporting data for the migration of Acheulean hominids from west to east in the Early Palaeolithic period.

Paleoclimate Variability in the Mediterranean and Red Sea Regions during the Last 500,000 Years

The Mediterranean–Red Sea region has been critical to dispersal of hominids and other species between Africa and the rest of the world, and climate and sea level are thought to be key controls on migration pathways. Assessing climate variations, we highlight increased millennial-scale variability at 480–460, 440–400, 380–360, 340–320, 260–220, 200–160, 140–120, and 80–40 thousand years ago (ka), which likely caused intermittent habitat fragmentation. We also find that passageways across the Sahara Desert and the northern out-of-Africa route (from Egypt into the Levant) were intermittently open during pluvials associated with orbital insolation maxima. No such relationship is apparent for the southern out-of-Africa route (across the Red Sea). Instead, we present a novel interpretation of combined sea-level and regional climate control on potential migrations via the southern route, with “windows of opportunity” at 458–448, 345–340, 272–265, 145–140, and 70–65 ka. The 145–140 ka window seems relevant for ea...

Age of the earliest Paleolithic sites in the northern part of the Armenian Highland by SHRIMP-II U–Pb geochronology of zircons from volcanic ashes

Understanding the earliest period of hominid dispersal from Africa to Eurasia requires reliable ages. Since artifacts are not suitable for direct dating, geochronology of an artifact host-rock matrix is the only robust approach. Possible matrix contamination limits the application of bulk mineral analysis, but the spatially selective secondary ionization mass spectrometry (SIMS) technique allows screening of contaminants. In two recently discovered Early Paleolithic sites in the northern Armenian Highland, the stratigraphic sequence includes ash-bearing volcanic layers with zircon autocrysts, suitable for SIMS U–Pb dating. At the Karakhach site, zircons from the ash-bearing volcanic layers yielded single age populations. This suggests that the layers were formed during multiple eruptions and were not reworked. Zircon crystallization ages of 1.942±0.046Ma, 1.804±0.030Ma, and 1.750±0.020Ma are close to eruptions and therefore date the enclosed Early Acheulian lithic artifacts. For artifacts underneath the oldest ash layer, the zircon age indicates the minimum age of artifacts. These results identify the Karakhach as the oldest Early Acheulian site in Eurasia. At the Kurtan site, the dated ash layer underlies palaeosols containing Early-Middle Acheulian artifacts. The stratigraphic succession at this site implies that the U–Pb zircon age of 1.432±0.028Ma from the ash is nearly coeval with the beginning of human occupation at the site.

Early hominid dispersals: A technological hypothesis for “out of Africa”

Homo is the only genus that responds to environmental pressures by adopting such strategies as non-standardized behaviour, a general diet, and technology. Considering that basic idea, this paper introduces the general hypothesis that the Pliocene and Early Pleistocene Homo dispersals within and out of Africa were consequences of that human characteristic behaviour. In particular, they were driven by a process starting with the emergence of technology, followed in a second phase by its socialization. From this point, social reorganization within communities (changing behaviours and social, cultural and economic strategies) occurred, driving demographic growth, and frequently geographic expansion.

The earliest hominid dispersals beyond Subsaharan Africa: A survey of underlying causes

Although anthropogenesis reaches back to Pliocene times in Subsaharan Africa, hominid dispersals beyond began only by the Early Pleistocene, with the appearance of genus Homo with Lower Palaeolithic repertoires. Causes responsible for these events remain poorly understood. Direct evidence for environmental factors, such as prolonged aridity stress or linkage with emigrating African ungulate or carnivorous species, while plausible, remains weak or ambiguous. Bio-cultural evolutionary evidence, however, provides more compelling indications, supported by empirical findings. These are rooted in the hominid ‘dual heritage’ involving higher primate ancestry and a partly but significant zoophagous dietary shift. Several million years of evolutionary divergence separated early Homo from its pongid relatives. The consequences of an omnivorous–carnivorous shift, on the other hand, besides enabling harvesting food resources at different levels of the trophic pyramid, included ‘natural history intelligence’, observed commonly among social carnivores. It enhanced human–landscape–plant–animal relationship and knowledge. It also favoured home-ranges expansion and the eurytopic adaptability of mobile ancient foraging hominids, as well as ecological polymorphism. The latter enabled hominids to adapt and exploit an increasing range of ecosytems, from the semi-arid tropics to subtropical steppes or woodlands, Mediterranean habitats, temperate woodland/grasslands, and a diversity of tropical forest formations in Eastern Asia. This adaptive versatility, linked with encephalization, particularly the expansion and increasing complexity of the brain cortex surface, was reinforced by cultural behaviour, best documented by technological behaviour. Lower Palaeolithic toolmaking demonstrates another behavioural discontinuity or technological ‘mutation’ by a familiarity and mastery, as ‘first geologists’, in acquiring suitable minerals, and skill in producing and using tools, as ‘secondary energy traps’ for various purposes, including prey carcass processing. Intermittent fire production represents another ‘mutation’ implying that hominids were virtually unique in overcoming the genetically inherited pyrophobic response, common among mammals. Cultural behaviour, as domain of socially acquired and transmitted interpretation and meaning of events, objects or activities, for mediating the world, pervades various aspects of human life (technology, subsistence, social life, cognition). It inserted progressively a new ‘cultural environment’ to which hominids became increasingly adapted and reliant on. This African dual heritage and bio-cultural evolutionary path documents how early hominids began following a new, hitherto unexploited adaptive niche, illustrated by long-range dispersals and gradual colonization of Eurasian ecosystems throughout the Pleistocene. This expansion became increasingly non-biological and contingent on cultural repertoires.

Using GIS and Ecological Variables to Identify High Potential Areas for Paleoanthropological Survey: An Example from Northern Armenia

The timing and nature of the initial hominid dispersals from Africa during the Plio-Pleistocene (here 2.0-1.5 million years ago [MYR]) is an issue of great interest for paleoanthropology. However, the biological, technological, and ecological context of these dispersals remains cloudy due largely to a paucity of Eurasian paleoanthropological sites dating to this time period. Indeed, there are only a handful of well-accepted Plio-Pleistocene sites from Eurasia: Dmanisi in the Republic of Georgia at 1.77-1.81 MYR (de Lumley et al. 2002), the Nihewan and Yuanmou basins of China at 1.66-1.70 MYR (Zhu et al. 2008), and the Indonesian island of Java at least 1.66 MYR (Sangiran) but perhaps as early as 1.81 MYR (Mojokerto) (Larick et al. 2001; Swisher et al. 1994). Although the Levant, given its geographic location, is the most logical extra- African source of dispersing hominid populations, the earliest well-accepted occupations there ('Ubeidiya in Israel) date to somewhat later in time at 1.4 MYR (Belmaker et al. 2002).

Earliest human remains in Eurasia: New 40Ar/ 39Ar dating of the Dmanisi hominid-bearing levels, Georgia

Several hominid remains have been discovered in the open-air site of Dmanisi (Georgia), the oldest prehistoric site in Eurasia. Two major arguments prove that this site is close in age to the Plio-Pleistocene boundary: a Villafranchian fauna and the morphological characteristics of hominid remains recently ascribed to Homo georgicus. Direct dating of the lower hominid-bearing level was carried out on volcanic glass and minerals using the 40Ar/ 39Ar method. The concordant results from two different sampled locations allow the determination of the age of the earliest human presence in Eurasia. This radioisotopic result strengthens the argument that the first dispersal of hominids outside Africa occurred at least 1.8 Ma ago.

Climate forcing of first hominid dispersal in Western Europe

Climate forcing of first hominid dispersal in Western Europe

Investigating early hominin dispersal patterns: developing a framework for climate data integration

An investigation using the Stepping Out model of early hominin dispersal out of Africa is presented here. The late arrival of early hominins into Europe, as deduced from the fossil record, is shown to be consistent with poor ability of these hominins to survive in the Eurasian landscape. The present study also extends the understanding of modelling results from the original study by Mithen and Reed (2002. Stepping out: a computer simulation of hominid dispersal from Africa. J. Hum. Evol. 43, 433–462). The representation of climate and vegetation patterns has been improved through the use of climate model output. This study demonstrates that interpretative confidence may be strengthened, and new insights gained when climate models and hominin dispersal models are integrated.

Landmark‐based shape analysis of the archaic Homo calvarium from Ceprano (Italy)

The Ceprano calvarium represents one of the most important sources of information about both the dynamics of the earliest hominid dispersal toward Europe and the evolution of the genus Homo in the early-to-middle Pleistocene. In this paper, the midsagittal vault profile and the 3D frontal bone morphology of Ceprano are investigated comparatively, using landmark coordinates and Procrustes superimposition. In fact, despite the fact that the skull appears partially distorted by diagenetic pressures (thus precluding a comprehensive landmark-based analysis), some aspects of the overall morphology are suitable for consideration in terms of geometric morphometrics. The midsagittal profile shows an archaic shape, comparable with the H. ergaster/erectus range of variation because of the fronto-parietal flattening, the development of the supraorbital and nuchal structures, and the occurrence of a slightly larger occipital bone. By contrast, the frontal bone displays a derived 3D shape that, mostly because of the widening of the frontal squama, appears comparable with the Afro-European variation of the Middle Pleistocene (i.e., H. heidelbergensis/rhodesiensis). Taking into account the unique morphological pattern displayed by Ceprano, its role as a link between early Homo and the Middle Pleistocene populations of Europe and Africa is not falsified. Thus, when aspects of the Ceprano's morphology are described within the analytical framework provided by geometric morphometrics, the relationships between Ceprano and the subsequent Afro-European fossil record are emphasized, suggesting the occurrence of an ancestral stock of H. heidelbergensis/rhodesiensis that is properly represented by the Italian specimen.

El poblamiento de Europa en torno al límite Matuyama/Brunhes: su origen y su significado en la evolución humana

A review of the European Lower Palaeolithic record shows three human dispersal episodes. The second one is dated between OIS25/OIS24-OIS19/OIS18. It is recorded by lithic assemblages and human remains that point to an eastern Asian origin. This paper reviews this hominid dispersal, related to the Galerian faunal event. Also we analyse the most feasible migratory routes, and the reasons of its abrupt ending. The phylogenetic relationships of these populations are also proposed, putting their context into the human evolutionary sequences of the Lower and Middle Pleistocene.

GEOLOGY OF THE HOMO -BEARING PLEISTOCENE DANDIERO BASIN (BUIA REGION, ERITREAN DANAKIL DEPRESSION)

This paper deals with the geological context of the northernmost site in the East Africa Rift system which has yielded Homo erectus -like remains. They are dated ca. 1 Ma and have been found in the deltaic deposits of the Alat Formation belonging to the Dandiero group. This newly defined group crops out extensively in an elongated belt from the Gulf of Zula to the North to the Garsat area to the south. In the Buia-Dandiero area it ranges in age from the Early to the Middle Pleistocene, and incorporates six formations, from bottom up: the fluvial Bukra Sand and Gravel, the deltaic and lacustrine Alat Formation, fluvial Wara Sand and Gravel, the lacustrine Goreya Formation, the fluvio-deltaic Aro Sand and alluvial Addai Fanglomerate. This succession is bounded by two major unconformities, which separate it from the Neoproterozoic basement and from the overlaying Boulder Beds fanglomerate, and has been designated the Maebele Synthem. The latter is the result of two lacustrine transgression and regressions evidenced by two depositional sequences. The unconformities bounding the Maebele Synthem are related to the tectonic history of the basin fill and its substrate. The development of the two sequences was, instead, mainly controlled by lake level fluctuations and, hence, by climatic variations connected with the weakening and strengthening of the monsoons in the northwestern Indian ocean. The environment where the Buia Homo lived was a savannah with some scattered water pools. This environment probably extended farther north along the western coastal plain of the Red Sea, and was a preferential pathway for the dispersal of the hominids from East Africa toward Eurasia.

Rome Awards: The hominid dispersal into Early to Middle Pleistocene Europe: an approach from biogeography

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Hominid Dispersals and Asian Biogeography during the Lower and Early Middle Pleistocene, c. 2.0-0.5 Mya

This paper examines the environmental context of human dispersals into Asia up to 0.5 mya. These dispersals were probably intermittent, often discontinuous, and initially confined to warm grasslands and open woodlands across southern Asia. During the Early Pleistocene, the effects of the uplift of Tibet and the inception of the monsoon were muted by the low-amplitude nature of northern hemisphere glaciations. By the Middle Pleistocene, further uplift, stronger monsoonal circulation, and higher-amplitude, glacial-interglacial cycles made much of Southwest and Central Asia more arid than previously. Two other Mid-Pleistocene developments were important: first, the appearance of Acheulean assemblages, possibly as far east as southern China; and secondly, the first appearance of hominids at latitudes 40–45oN during interglacial episodes. Hominid dispersals in both Europe and Asia were probably broadly similar in that hominids did not habitually live beyond 40oN until c. 500 kya. Rather than dividing Asia longitudinally into areas east or west of the Movius line, latitudinal divisions between warm/hot and cool/cold environments might be more appropriate.

Asia and the Middle Pleistocene in Global Perspective

DIFFERENCES AMONG THE ASIAN, AFRICAN, AND EUROPEAN PREHISTORIC records are well documented by assemblages that illustrate technological variability and diverse subsistence strategies. Until recently these differences were interpreted without detailed knowledge of Asian paleoenvironments. In addition, early Pleistocene hominid expansions from Africa into regions of Asia, once thought to have taken place no earlier than one million years ago, are now unquestionably much older. Not only did these movements greatly enlarge the human territory, but they also exposed humans to the vast array of resources they still exploit today. Hominid encounters with Asian environments involved the continued exploitation of grasslands and also offered the challenge of adaptation to uplands, colder regions, and sub-tropical zones--a pattern that became widespread during the Middle Pleistocene (787-127 kya, corresponding to Oxygen Isotope Stages 19-6). These topics were the focus of a conference and discussions held in 2001 at the East-West Center in Honolulu (see Miller-Antonio et al. [2001] for more details on the conference). Selected papers from that meeting are collected in this volume, and serve as a forum for exchange between parts of the world that have long been studied in relative isolation. Figure 1 presents a regional map of localities discussed in these papers. [FIGURE 1 OMITTED] To provide historical background for Paleolithic research in Asia, the volume begins with a tribute to Jia Lanpo, a scholar whose work was critical in the establishment of Asian prehistory and who played a major role in the debates on the archaeological relationship between Asia and the West. The highly integrative nature of his work made the Chinese prehistoric record accessible to scholars worldwide. This tribute is followed by an interview with one of China's foremost archaeologists and Jia's student, Huang Weiwen. It is a retrospective on the development of prehistoric research in China, and an examination of the similarities and differences among archaeological perspectives and approaches in other Asian countries. The next three papers examine Asia from a broad perspective, discussing the impact of climate change and the opening of new environmental niches. Dennell synthesizes the latest information on paleoclimates linked to the uplift of the Himalayas and the formation of the Asian monsoon pattern. He identifies two key trends in hominid dispersals. The first is that earliest movements into southern Asia involved use of the grassland niche familiar to African hominids. He correlates the first appearance of Acheulean assemblages in Southwest and South Asia with increasingly and conditions in the Lower Pleistocene. Slightly later in time, biracial assemblages characterize early sites in southern China. A second trend, apparent in the late Lower Pleistocene, involved the expansion into colder environments and the use of non-Acheulean, simple core and flake (Mode 1) tools. Keates provides an overview of hominid home range size in Middle Pleistocene China using data on raw material source distance. She then examines how faunal dispersals (most notably Equus) and water availability affect hominid expansions into colder climates. She also uses arguments based on hominid morphology to support the idea of interaction and sustained migrations between eastern Asian and Eurasian populations. One key component of adaptations to colder Eurasian environments was undoubtedly the ability to use and control fire. …

Home Range Size in Middle Pleistocene China and Human Dispersal Patterns in Eastern and Central Asia

Home range size in Middle Pleistocene China can be explored based on various lines of evidence. This paper provides a brief review of home range size from the perspectives of raw material source distance and the geographic location of archaeological localities in the eastern half of China. In most cases, hominids exploited lithic materials for tool manufacture from sources close to their camps. This is indicative of small home range size in the Middle Pleistocene of this region. Hominid occupation of upland localities in the later Middle Pleistocene may reflect a larger home range than previously. In the wider geographic context, based on faunal dispersals, hominid morphology, and also with reference to some relevant ecological hypotheses, it is diäcult to defend the idea of geographic isolation of Eastern Asia in the Pleistocene. Rather, it seems that hominid dispersal within Eurasia may have been a significant behavioral attribute contributing to the evolution and survival of Homo species.

An ecomorphological model of the initial hominid dispersal from Africa.

We use new data on the timing and extent of the early Pleistocene dispersal of Homo erectus to estimate diffusion coefficients of early Homo from Africa. These diffusion coefficients indicate more rapid and efficient dispersals than those calculated for fossil Macaca sp., Theropithecus darti, and Mesopithecus pentelicus. Increases in home range size associated with changes in ecology, hominid body size, and possibly foraging strategy may underlay these differences in dispersal efficiency. Ecological data for extant primates and human foragers indicate a close relationship between body size, home range size, and diet quality. These data predict that evolutionary changes in body size and foraging behavior would have produced a 10-fold increase in the home range size of H. erectus compared with that of the australopithecines. These two independent datasets provide a means of quantifying aspects of the dispersal of early Homo and suggest that rapid rates of dispersal appear to have been promoted by changes in foraging strategy and body size in H. erectus facilitated by changes in ecosystem structure during the Plio-Pleistocene.

Stepping out: a computer simulation of hominid dispersal from Africa

A succession of new discoveries and the recent application of new dating methods provide strong evidence that Eurasia was colonized soon after 2.0m.y.a. In light of this new evidence many scenarios have been proposed regarding the influence of glacial/interglacial cycles on hominid dispersal, the role of mountain chains and deserts as barriers, the significance of land bridges and the possibility of sea-crossings. Such factors have been proposed to explain the apparent early arrival of hominids in East Asia and relatively late arrival in Europe, although the evidence in both regions remains open to various interpretations. While it is relatively easy to propose environmental factors that may have influenced dispersal patterns, it is more difficult to evaluate such proposals and to establish what the combined impact of several factors might have been. Moreover, the role of historical contingency in creating the observed pattern of dispersal has yet to be considered. This paper describes a computer simulation model of hominid dispersal which seeks to provide a means to evaluate environmental and ecological factors in hominid dispersal. It creates probability distributions for arrival dates at six key localities and compares these with current estimates from the archaeological and fossil records. It uses these to support some of the current arguments about dispersal and to challenge others.

Stepping out: a computer simulation of hominid dispersal from Africa

Stepping out: a computer simulation of hominid dispersal from Africa