Early Modern Human Dispersal Research Articles

Concurrent Asian monsoon strengthening and early modern human dispersal to East Asia during the last interglacial.

The relationship between initial Homo sapiens dispersal from Africa to East Asia and the orbitally paced evolution of the Asian summer monsoon (ASM)-currently the largest monsoon system-remains underexplored due to lack of coordinated synthesis of both Asian paleoanthropological and paleoclimatic data. Here, we investigate orbital-scale ASM dynamics during the last 280 thousand years (kyr) and their likely influences on early H. sapiens dispersal to East Asia, through a unique integration of i) new centennial-resolution ASM records from the Chinese Loess Plateau, ii) model-based East Asian hydroclimatic reconstructions, iii) paleoanthropological data compilations, and iv) global H. sapiens habitat suitability simulations. Our combined proxy- and model-based reconstructions suggest that ASM precipitation responded to a combination of Northern Hemisphere ice volume, greenhouse gas, and regional summer insolation forcing, with cooccurring primary orbital cycles of ~100-kyr, 41-kyr, and ~20-kyr. Between ~125 and 70 kyr ago, summer monsoon rains and temperatures increased in vast areas across Asia. This episode coincides with the earliest H. sapiens fossil occurrence at multiple localities in East Asia. Following the transcontinental increase in simulated habitat suitability, we suggest that ASM strengthening together with Southeast African climate deterioration may have promoted the initial H. sapiens dispersal from their African homeland to remote East Asia during the last interglacial.

The Role of Plant Foods in the Evolution and Dispersal of Early Humans: A Perspec- tive from Across the Wallace Line

In recent years, new evidence for the early use of plant foods has challenged the stereotype of the meat-eating Paleolithic. Whilst often making up the smaller component of the diet, plant foods are key to hominin diets, carbohydrates especially providing an efficient energy resource. This paper reviews the current evidence for the role of plant foods in the evolution and dispersal of early modern humans and our closest ancestors, with a focus on new evidence for early diet from Island Southeast Asia, Australia and New Guinea. It demonstrates the importance of plant foods and their processing, to the dietary flexibility and adaptive capacity of our species.

Refining models of archaic admixture in Eurasia with ArchaicSeeker 2.0

We developed a method, ArchaicSeeker 2.0, to identify introgressed hominin sequences and model multiple-wave admixture. The new method enabled us to discern two waves of introgression from both Denisovan-like and Neanderthal-like hominins in present-day Eurasian populations and an ancient Siberian individual. We estimated that an early Denisovan-like introgression occurred in Eurasia around 118.8–94.0 thousand years ago (kya). In contrast, we detected only one single episode of Denisovan-like admixture in indigenous peoples eastern to the Wallace-Line. Modeling ancient admixtures suggested an early dispersal of modern humans throughout Asia before the Toba volcanic super-eruption 74 kya, predating the initial peopling of Asia as proposed by the traditional Out-of-Africa model. Survived archaic sequences are involved in various phenotypes including immune and body mass (e.g., ZNF169), cardiovascular and lung function (e.g., HHAT), UV response and carbohydrate metabolism (e.g., HYAL1/HYAL2/HYAL3), while “archaic deserts” are enriched with genes associated with skin development and keratinization.

Disentangling Sedimentary Pathways for the Pleniglacial Lower Danube Loess Based on Geochemical Signatures

The source of aeolian sediments such as loess has been investigated since decades. Reliable knowledge on potential dust sources is crucial to understand past climatic and environmental conditions accompanying the dispersal of early modern humans (EMH) into Europe. Provenance studies are usually performed on small sample sets and most established methods are expensive and time-consuming. Here, we present the results of high-resolution geochemical analyses performed on five loess-palaeosol sequences from the Lower Danube Basin (LDB), a region, despite its importance as a trajectory for EMH, largely underrepresented in loess provenance studies. We compare our results with geochemical data of loess-palaeosol sequences from Austria, Hungary, Serbia, and Ukraine. Based on published literature, we thus evaluate five plausible sedimentary pathways for the LDB loess: 1) the Danube alluvium (DA) pathway, which constrains the transport and re-deposition of detrital material by the Danube and its tributaries; 2) the Carpathian Bending (CB) pathway, where sediment is mainly transported from the Cretaceous to Neogene flysch of the Eastern Carpathian Bending; 3) the Eastern Carpathian (EC) pathway, in which sediment is eroded from the flysch of the Outer Eastern Carpathians, transported by rivers, and deflated by northwesterly to westerly winds; 4) the glaciofluvial (GF) pathway, where dust is deflated from glacial outwash plains in nowadays Ukraine, and 5) the Black Sea (BS) pathway, where dust originates from the exposed shelf of the Black Sea. Based on geochemical data, we consider the DA pathway to be the major sediment trajectory for loess in the LDB. Especially the sequences located close to the Danube and the Dobrogea show similarities to sites in Central and Northeast Hungary as well as Northern Serbia. For the northeastern part of the LDB, we demonstrate that dust input is mainly sourced from primary material from the Eastern Carpathians. Mineralogical estimations and geochemical data render the CB pathway as an additional substantial source of detrital material for the loess of this area. We consider the influence of the GF pathway in the LDB as negligible, whereas some minor influences of the BS pathway cannot be ruled out based on geochemical data.

Early modern human dispersal into southwest Asia occurred in variable climates: a reply to Frumkin and Comay (2019)

Early modern human dispersal into southwest Asia occurred in variable climates: a reply to Frumkin and Comay (2019)

The northern dispersal of early modern humans in eastern Eurasia

The northern dispersal of early modern humans in eastern Eurasia

The first Australian plant foods at Madjedbebe, 65,000\u201353,000 years ago

There is little evidence for the role of plant foods in the dispersal of early modern humans into new habitats globally. Researchers have hypothesised that early movements of human populations through Island Southeast Asia and into Sahul were driven by the lure of high-calorie, low-handling-cost foods, and that the use of plant foods requiring processing was not common in Sahul until the Holocene. Here we present the analysis of charred plant food remains from Madjedbebe rockshelter in northern Australia, dated to between 65 kya and 53 kya. We demonstrate that Australia’s earliest known human population exploited a range of plant foods, including those requiring processing. Our finds predate existing evidence for such subsistence practices in Sahul by at least 23ky. These results suggest that dietary breadth underpinned the success of early modern human populations in this region, with the expenditure of labour on the processing of plants guaranteeing reliable access to nutrients in new environments.

Before the massive modern human dispersal into Eurasia: A 55,000-year-old partial cranium from Manot Cave, Israel

Genetic and archaeological models predict that African modern humans successfully colonized Eurasia between 60,000 and 40,000 years before present (ka), replacing all other forms of hominins. While there is good evidence for the first arrival in Eurasia around 50-45ka, the fossil record is extremely scarce with regard to earlier representatives. A partial calvaria discovered at Manot Cave (Western Galilee, Israel) dated to >55 ka by uranium–thorium dating was recently described. Since then, other findings indicated an early dispersal of modern humans out-of-Africa between 194 and 177ka (Misliya-1) or possibly even earlier at 210ka (Apidima 1), and a quite long existence of Homo sapiens in Africa (Jebel Irhoud, ~300ka). While the faces of these early Homo sapiens appear quite modern, the shape of the braincase seems to lack behind, reaching the modern state only around after 35ka. Here, new data and approaches were applied to the Manot 1 calvaria. The ecto- and endocranial shape analyses based on micro-computed tomography data and a landmark-semilandmark approach using multiple reconstructions of the incomplete calvaria confirm that Manot 1 is unequivocally modern human. Its endocranial shape is markedly different from the earliest known Homo sapiens and close to the Levantine Qafzeh/Skhul assemblage (120-90ka) as well as modern humans, but still shows some deviations from both groups. The absence of other Homo sapiens fossils in the Levant between the Qafzeh/Skhul and Manot populations is not supportive for the hypothesis of a continuous occupation or the local evolution of modern humans. It suggests that Manot 1 represents a population migrating out-of-Africa and reaching the Levantine corridor during warmer and wetter climatic conditions over the Northern Sahara and the Mediterranean. Manot 1 shows that both modern humans and Neanderthals (e.g. Kebara, Amud) contemporaneously inhabited the Levant during the Middle to Upper Paleolithic interface. The endocranial shape of Manot 1 might indicate that this population had not yet fully reached the brainshape of modern humans evident after 35ka.

An early dispersal of modern humans from Africa to Greece

Analysis of two fossils from a Greek cave has shed light on early hominins in Eurasia. One fossil is the earliest known specimen of Homo sapiens found outside Africa; the other is a Neanderthal who lived 40,000 years later. Fossil from Greece is the earliest known Homo sapiens in Europe.

The Aurignacian way of life: Contextualizing early modern human adaptation in the Carpathian Basin

The culture and dispersal of early modern humans are top priorities of many research agendas. While the debate primarily centers on genetics, dispersal trajectories and points of earliest presence, the context (climate, landscape, demography, culture) of the colonizing process is usually considered in a coarse-grained manner or even ignored. To understand the context of human dispersal and to decipher relevant push and pull factors requires the consideration of multiple environmental proxies and the research on different geographic scales. In this paper, we present the Late Quaternary Carpathian Basin as a specific context area of early modern human dispersal into Europe. The multitude of Early Upper Paleolithic sites in this region suggests that it was part of a major dispersal corridor along the Danube and its catchment area some 40,000 years ago. The Aurignacian land-use model describes the interaction of early modern humans with their environment. One important parameter is the specific distribution of archaeological sites that exemplifies their boundedness to specific eco-zones. To reconstruct the latter, paleo-environmental proxies and archaeological data are examined together in regional vector models and in a GIS based landscape archaeology approach. In the final section, we present the Carpathian Basin as an idiosyncratic habitat that mirrors the dynamics and complexity of early modern human adaptation.

The Simons Genome Diversity Project: 300 genomes from 142 diverse populations.

We report the Simons Genome Diversity Project (SGDP) dataset: high quality genomes from 300 individuals from 142 diverse populations. These genomes include at least 5.8 million base pairs that are not present in the human reference genome. Our analysis reveals key features of the landscape of human genome variation, including that the rate of accumulation of mutations has accelerated by about 5% in non-Africans compared to Africans since divergence. We show that the ancestors of some pairs of present-day human populations were substantially separated by 100,000 years ago, well before the archaeologically attested onset of behavioral modernity. We also demonstrate that indigenous Australians, New Guineans and Andamanese do not derive substantial ancestry from an early dispersal of modern humans; instead, their modern human ancestry is consistent with coming from the same source as that in other non-Africans.

Population genetics: A map of human wanderlust.

Genetic studies of individuals from geographically diverse human populations provide insights into the dispersal of modern humans across the globe and how geography shaped genomic variation. See Articles p.201 & p.207 & Letter p.238 Three international collaborations reporting in this issue of Nature describe 787 high-quality genomes from individuals from geographically diverse populations. David Reich and colleagues analysed whole-genome sequences of 300 individuals from 142 populations. Their findings include an accelerated estimated rate of accumulation of mutations in non-Africans compared to Africans since divergence, and that indigenous Australians, New Guineans and Andamanese do not derive substantial ancestry from an early dispersal of modern humans but from the same source as that of other non-Africans. Eske Willerlsev and colleagues obtained whole-genome data for 83 Aboriginal Australians and 25 Papuans from the New Guinea Highlands. They estimate that Aboriginal Australians and Papuans diverged from Eurasian populations 51,000–72,000 years ago, following a single out-of-Africa dispersal. Luca Pagani et al. report on a dataset of 483 high-coverage human genomes from 148 populations worldwide, including 379 new genomes from 125 populations. Their analyses support the model by which all non-African populations derive most of their genetic ancestry from a single recent migration out of Africa, although a Papuan contribution suggests a trace of an earlier human expansion.

Islands Under the Sea: A Review of Early Modern Human Dispersal Routes and Migration Hypotheses Through Wallacea

ABSTRACTWallacea is the transitional biogeographic zone between the continents of Sunda (Southeast Asia) and Sahul (Australian-New Guinea). It consists of a series of island chains unique in the region for never having been connected to either continent. Movement of early modern humans from Sunda to Sahul during the late Pleistocene required dispersal through Wallacea, and hence would have necessitated sea crossings. However, the archeological evidence for early modern humans in Wallacea is still a work in progress, and none of it pre-dates the archeological record from Sahul. While numerous models of this significant colonization event have been proposed, selecting the most likely model for first landfall in Sahul using current archeological evidence has proven difficult, if not impossible. Here the late Pleistocene archeological evidence of early modern humans from Wallacea and its neighbors are reviewed, and the key colonization models that have been proposed are explored. We consider the use of computer simulations and the input variables necessary to test the likelihood of the different colonization models. We highlight the importance of the greater than 100 additional submerged islands observed within the Wallacean archipelago following a simple analysis of bathymetric data and sea-level curves, and their potential impacts on the dispersal and ecology of early human colonizers.

Early modern human dispersal from Africa: genomic evidence for multiple waves of migration.

BackgroundAnthropological and genetic data agree in indicating the African continent as the main place of origin for anatomically modern humans. However, it is unclear whether early modern humans left Africa through a single, major process, dispersing simultaneously over Asia and Europe, or in two main waves, first through the Arab Peninsula into southern Asia and Oceania, and later through a northern route crossing the Levant.ResultsHere, we show that accurate genomic estimates of the divergence times between European and African populations are more recent than those between Australo-Melanesia and Africa and incompatible with the effects of a single dispersal. This difference cannot possibly be accounted for by the effects of either hybridization with archaic human forms in Australo-Melanesia or back migration from Europe into Africa. Furthermore, in several populations of Asia we found evidence for relatively recent genetic admixture events, which could have obscured the signatures of the earliest processes.ConclusionsWe conclude that the hypothesis of a single major human dispersal from Africa appears hardly compatible with the observed historical and geographical patterns of genome diversity and that Australo-Melanesian populations seem still to retain a genomic signature of a more ancient divergence from AfricaElectronic supplementary materialThe online version of this article (doi:10.1186/s13323-015-0030-2) contains supplementary material, which is available to authorized users.

Early dispersal of modern humans in Europe and implications for Neanderthal behaviour

The appearance of anatomically modern humans in Europe and the nature of the transition from the Middle to Upper Palaeolithic are matters of intense debate. Most researchers accept that before the arrival of anatomically modern humans, Neanderthals had adopted several 'transitional' technocomplexes. Two of these, the Uluzzian of southern Europe and the Châtelperronian of western Europe, are key to current interpretations regarding the timing of arrival of anatomically modern humans in the region and their potential interaction with Neanderthal populations. They are also central to current debates regarding the cognitive abilities of Neanderthals and the reasons behind their extinction. However, the actual fossil evidence associated with these assemblages is scant and fragmentary, and recent work has questioned the attribution of the Châtelperronian to Neanderthals on the basis of taphonomic mixing and lithic analysis. Here we reanalyse the deciduous molars from the Grotta del Cavallo (southern Italy), associated with the Uluzzian and originally classified as Neanderthal. Using two independent morphometric methods based on microtomographic data, we show that the Cavallo specimens can be attributed to anatomically modern humans. The secure context of the teeth provides crucial evidence that the makers of the Uluzzian technocomplex were therefore not Neanderthals. In addition, new chronometric data for the Uluzzian layers of Grotta del Cavallo obtained from associated shell beads and included within a Bayesian age model show that the teeth must date to ~45,000-43,000 calendar years before present. The Cavallo human remains are therefore the oldest known European anatomically modern humans, confirming a rapid dispersal of modern humans across the continent before the Aurignacian and the disappearance of Neanderthals.

The earliest evidence for anatomically modern humans in northwestern Europe

The earliest anatomically modern humans in Europe are thought to have appeared around 43,000-42,000 calendar years before present (43-42 kyr cal BP), by association with Aurignacian sites and lithic assemblages assumed to have been made by modern humans rather than by Neanderthals. However, the actual physical evidence for modern humans is extremely rare, and direct dates reach no farther back than about 41-39 kyr cal BP, leaving a gap. Here we show, using stratigraphic, chronological and archaeological data, that a fragment of human maxilla from the Kent's Cavern site, UK, dates to the earlier period. The maxilla (KC4), which was excavated in 1927, was initially diagnosed as Upper Palaeolithic modern human. In 1989, it was directly radiocarbon dated by accelerator mass spectrometry to 36.4-34.7 kyr cal BP. Using a Bayesian analysis of new ultrafiltered bone collagen dates in an ordered stratigraphic sequence at the site, we show that this date is a considerable underestimate. Instead, KC4 dates to 44.2-41.5 kyr cal BP. This makes it older than any other equivalently dated modern human specimen and directly contemporary with the latest European Neanderthals, thus making its taxonomic attribution crucial. We also show that in 13 dental traits KC4 possesses modern human rather than Neanderthal characteristics; three other traits show Neanderthal affinities and a further seven are ambiguous. KC4 therefore represents the oldest known anatomically modern human fossil in northwestern Europe, fills a key gap between the earliest dated Aurignacian remains and the earliest human skeletal remains, and demonstrates the wide and rapid dispersal of early modern humans across Europe more than 40 kyr ago.

Genes, Fossils, and Culture. An Overview of the Evidence for Neandertal–Modern Human Interaction and Admixture

This paper re-examines current arguments concerning the evidence for Neandertal-modern human interaction and admixture. While most researchers now agree that the ancestry of all present day humans can be traced back to African late Middle Pleistocene populations, at a time when the remainder of Eurasia was inhabited by ‘archaic humans’, most notably the Neandertals, issues that remain to be resolved are the tempo and mode of early modern human dispersal and interaction with archaic humans.This paper focuses on what happened at the time of contact in Europe, and assesses the level of admixture that may have occurred, as well as the extent to which such level may have varied in both time and space. It explains how the available mtDNA evidence does not preclude admixture at the time of contact, and is in fact consistent, depending on a number of parameters, with a possibly substantial Neandertal contribution to the initial modern human population of Europe. It is argued that the absence of Neandertal mtDNA lineages among present Europeans is likely, on dating evidence, to be simply a particular case of generalised loss of Pleistocene mtDNA lineages. Although the full range of interaction types (mutual avoidance, hostile confrontation, full integration) is conceivable, there is plenty of archaeological evidence to suggest that admixture must have been the general rule, and that the paleontological evidence for the generalised presence of archaic traits among Europe's earliest moderns implies the transmission of genes, and indicates that mixed groups should have been reproductively viable. In this context, it would seem that the most parsimonious explanation for the disappearance of the Neandertal mtDNA lineage is genetic swamping.

Palaeoenvironments of insular Southeast Asia during the Last Glacial Period: a savanna corridor in Sundaland?

Consideration of a range of evidence from geomorphology, palynology, biogeography and vegetation/climate modelling suggests that a north-south ‘savanna corridor’ did exist through the continent of Sundaland (modern insular Indonesia and Malaysia) through the Last Glacial Period (LGP) at times of lowered sea-level, as originally proposed by Heaney [1991. Climatic Change 19, 53–61]. A minimal interpretation of the size of this corridor requires a narrow but continuous zone of open ‘savanna’ vegetation 50–150 km wide, running along the sand-covered divide between the modern South China and Java Seas. This area formed a land bridge between the Malaysian Peninsula and the major islands of Sumatra, Java and Borneo. The savanna corridor connected similar open vegetation types north and south of the equator, and served as a barrier to the dispersal of rainforest-dependent species between Sumatra and Borneo. A maximal interpretation of the available evidence is compatible with the existence of a broad savanna corridor, with forest restricted to refugia primarily in Sumatra, Borneo and the continental shelf beneath the modern South China Sea. This savanna corridor may have provided a convenient route for the rapid early dispersal of modern humans through the region and on into Australasia.

Depletion of a resource? The impact of prehistoric human foraging on intertidal mollusc communities and its significance for human settlement, mobility and dispersal

Ethnoecological studies have demonstrated the impacts that even relatively small-scale human foraging has on targeted species of shellfish and the structure of biological communities in intertidal zones. There is compelling archaeological evidence that people in various parts of the world often had a depleting effect on shellfish populations. Shellfish and other marine resources have sometimes been perceived as lowly ranked foods and coastal archaeological sites have often been interpreted as temporary (possibly seasonal) sites for the exploitation of these 'inferior' food resources. This model has been challenged by studies of mid-Holocene Mesolithic hunter-gatherer sites in Atlantic Europe, which have shown that marine foods were the main component of the total diet and that human foraging can deplete shellfish resources. Although subsistence systems based on coastal resources might have been both viable and acceptable in dietary terms, regular mobility would have been necessary for them to be sustainable. On longer time scales, such coastal mobility might result in population dispersal. Sites associated with early anatomically modern humans show the antiquity of coastal adaptations, including the consumption of shellfish, and the dispersal of early modern humans out of Africa into south-east Asia and 'Greater Australia' could have been through coastal environments. This coastal dispersal could have been driven, at least in part, by the impact of early human foragers on intertidal food resources. Resource depletion in coastal zones was probably among the first significant, but small-scale, 'ecological impacts' of human beings.