How did Homo sapiens expand out of Africa into Eurasia?

Current fossil, genetic, and archaeological data indicate that Homo sapiens originated in Africa in the late Middle Pleistocene. By the end of the Late Pleistocene, our species was distributed across every continent except Antarctica, setting the foundations for the subsequent demographic and cultural changes of the Holocene. The intervening processes remain intensely debated and a key theme in hominin evolutionary studies.

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The distribution of Middle Paleolithic sites across East Africa, the Saharo-Arabian belt, and India, plotted on a modeled precipitation map for the last interglacial (MIS 5) with positions of major paleolakes (dark blue areas) and paleorivers, which form extensive riparian corridors (blue lines)

In this paper we review archaeological, fossil, environmental, and genetic data to evaluate the current state of knowledge on the dispersal of Homo sapiens out of Africa. The emerging picture of the dispersal process suggests dynamic behavioral variability, complex interactions between populations, and an intricate genetic and cultural legacy. This evolutionary and historical complexity challenges simple narratives and suggests that hybrid models and the testing of explicit hypotheses are required to understand the expansion of Homo sapiens into Eurasia.

Read  more in Rethinking the Dispersal of Homo sapiens out of Africa in Evolutionary Anthropology.

The western Nefud from the air

In January 2016, colleagues from the Palaeodeserts project and Saudi Geological Survey (SGS) performed a collaborative aerial survey of locations across the western Nefud.
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Dr’s Armitage and Groucutt surveying the Nefud from the air


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Dr Iyad Zalmout of the SGS and the SGS helicopter

The use of the SGS helicopter allowed the team to examine numerous new locations deep in the Nefud, where major lake sediment outcrops testify to much wetter episodes in the past of this arid area.


In combination with the analysis of satellite datasets, the results of these collaborative expeditions are revealing the overall distribution of surviving lake sediments, fossils and archaeology across the whole western Nefud, including areas away from the accessible desert fringes.

The team sampling and surveying deep in the Nefud desert

The team sampling and surveying deep in the Nefud desert

By using these data, and dating the lake sediments and archaeology and fossils that highlight their former exploitation by prehistoric populations and animals, the team is gradually forming a picture of how the environments and occupation of this area of the Nefud have changed over prehistory.

Hominin occupations of the Arabian Peninsula

The Pleistocene archaeological record of the Arabian Peninsula is increasingly recognized as being of great importance for resolving some of the major debates in hominin evolutionary studies. Though there has been an acceleration in the rate of fieldwork and discovery of archaeological sites in recent years, little is known about hominin occupations in the Pleistocene over vast areas of Arabia.


Lithics made of a fine grained igneous raw material or rhyolite

The importance of these sites centers on their diversity in terms of landscape positions, raw materials used for lithic manufacture, and core reduction methods. Our findings indicate multiple hominin dispersals into Arabia and complex subsequent patterns of behavior and demography.

Read more in The Middle Palaeolithic of the Nejd, Saudi Arabia in the Journal of Field Archaeology.

Revealing the Stone Age History of Saudi Arabia

Huw Groucutt with a handaxe in the western Nefud

Huw Groucutt with a handaxe in the western Nefud

Today you would not survive the hostile deserts of Arabia without desalination plants and four-wheel drives – or, at the very least, deep wells and camels. Yet, as Huw Groucutt reveals, a wealth of rock art and quantities of ancient stone tools prove that people managed to survive here in the long-distant past.

Read more in First Arabians – Revealing the Stone Age History of Saudi Arabia in Current World Archaeology.

Reconstructing ancient rivers and lakes in Arabia

Freshwater availability is critical for human survival, and its availability in the Arabian Peninsula in the past was likely to have been a primary control upon routes and opportunities for the movement and dispersal of early humans.

Results of palaeohydrological analyses focussed upon the southern Nefud region, showing mapped drainage (questionable drainage in dunes marked in grey), and modelled palaeolake extents

Results of palaeohydrological analyses focussed upon the southern Nefud region, showing mapped drainage (questionable drainage in dunes marked in grey), and modelled palaeolake extents

With this in mind, Palaeodeserts team member Paul Breeze developed new palaeohydrological methods during his doctoral research. Remote sensing and GIS techniques were used to map palaeochannels (ancient water channels) across the whole of the Arabian Peninsula, and palaeolakes and marshes for select regions covering approximately 10% of its surface area.


Field survey by the Palaeodeserts team in the Nefud desert and the Dawadmi and Shuwaymis regions of Saudi Arabia has indicated accuracies of 86% for the palaeodrainage mapping, and of 96% for the method for identifying former palaeolake basins. These data are now being used by the project for targeted field survey, as the new palaeolake mapping method has also demonstrated potential for identifying surface and stratified archaeological site locations, with 76% of the surveyed palaeolake basins containing archaeological material, including stratified Palaeolithic archaeology.

Acheulean landscapes in the Arabian Peninsula


Surveying one of the many dykes in the Dawadmi region. The dykes consists of magma intrusions that have cooled and hardened into rock, typically andesite. The fine-grained nature of these rocks made them a target for Acheulean hominins – the slopes of these dykes contain lithic debris from biface manufacture

Our systematic survey of Acheulean occupation evidence at Dawadmi, in the heart of the Arabian Peninsula, has led to the discovery of 14 new Acheulean sites at Saffaqah, and a further 22 sites in the Dawadmi area.

Our survey revealed a strong correlation between Acheulean sites and fine-grained andesite dykes, a major source of raw material for stone tools; no Acheulean sites in the study area were found away from dykes or their adjacent landscape units. Based on dyke distributions, the geographic range of Acheulean activity is estimated to be 100km × 55km, making Dawadmi one of the largest Acheulean landscapes in the world.

Read more in Multi-scale Acheulean landscape survey in the Arabian Desert in Quaternary International.


Symposium at Society for American Archaeology conference

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Dr Huw Groucutt points to a layer of fossils and stone tools in sediments dating to around 100 thousand years ago. Ancient lakes drew people into Arabia, but from where did they come?”

Palaeodeserts team member Huw Groucutt (University of Oxford) is running a symposium at the Society for American Archaeology conference in Orlando, Florida on April 7th 2016. The title of the session is “Parting the Red Sea:  Late Pleistocene Human Dispersals and Lithic Variability in the Horn of Africa and Arabia”.

The meeting is co-organised with Steven Brandt (University of Florida) and Yonatan Sahle (University of California, Berkeley). As well as a presentation by Huw Groucutt, Palaeodeserts is represented by Michael Petraglia, who is a discussant for the session. A workshop is being held at the University of Florida in the days before the conference to allow extended discussions on the topics. The workshop and conference symposium will allow us to present our exciting new findings from Arabia, and discuss the wider significance of these with colleagues working in surrounding regions.

Click here for details.

Symposium on Human Colonization of Asia in the Late Pleistocene

Eurasia map-NEW1The Wenner-Gren Symposium #153 on “Human Colonization of Asia in the Late Pleistocene” will be held March 18-24, 2016, at Tivoli Palacio de Seteais in Sintra, Portugal. The conference is organized by Christopher Bae (University of Hawai’i at Manoa), and Michael Petraglia and Katerina Douka, both of Oxford University.

Click here for details of the Symposium.

Palaeodeserts Presentation at Red Sea Conference, Jeddah

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Michael Petraglia with colleagues from King Saud University, the Saudi Geological Survey and participants at the Workshop

Michael Petraglia gave a talk entitled “Green Arabia, Blue Arabia: Examining Human Colonisation and Dispersal Models”, at the 2nd Jeddah International Workshop on the Geological Setting, Oceanography and Environment of the Red Sea, organised by the Saudi Geological Survey.

Petraglia presented research on coastal versus interior zone models, situating archaeological sites into an over-arching framework to better understand the human population history of the Arabian Peninsula.  Springer Press will publish papers from this interdisciplinary conference.

Rock art sheds new light on the Neolithic transition in Arabia

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Photograph and tracing of rock art panel at Shuwaymis. White lines show the original hunting scene; blue lines show a later herding scene which includes the re-engraved shapes of a hunter and three dogs

Our study of the engraved rock art recorded on 254 panels in Shuwaymis, Ha’il Province, has shed more light on the Neolithic transition from hunting and gathering to economies utilising domesticated livestock in this part of the Arabian Peninsula.

In particular, the re-use of hunting panels to create herding scenes, the re-engraving of hunting figures into herders, and the re-carving of hunting dogs into pastoral scenes all suggest that the engravers of herding panels still identified with the depicted hunters.

Read more in Hunters and herders: Exploring the Neolithic transition in the rock art of Shuwaymis, Saudi Arabia.