Over the last 2 million years, multiple generations of our ancestors have occupied the now-desert regions of North Africa, Arabia and Southern Asia, expanding through them to eventually spread across the entire globe.
These populations left their mark in the millions of stone artefacts they left in these regions, artefacts that are now spread across the surface of deserts and semi-arid areas across the Saharo-Arabian desert belt. By mapping where these artefacts are found, archaeologists can begin to interpret which features of the landscape were used frequently by different species of the Homo genus, such as our predecessors in Arabia and Asia, Homo erectus (1.8 million years ago to 150,00 years ago), and our own species Homo sapiens (200,000 years ago to present). These differences in the ways in which different species used the landscape is important because it can tell us about the differences in behavior, and potentially cognitive and technological capabilities of these species, which in turn will tell us more about the history of human peopling of the globe
But the landscapes inhabited by our ancestors, and in which these artefacts were left, have undergone massive changes over time, changes driven by environmental change or long-term geomorphological or tectonic processes. Rivers ceased to flow, lakes expanded and then disappeared, and shorelines moved for tens of kilometers through sea level changes. As well as removing the landscape features artefacts were associated with, these processes of landscape change also moved, buried, and exposed these artefacts, fundamentally shaping where archaeologists would find them in the present day.
In addition, the distribution of artefacts across the surface of these continents represents the activities of populations up to thousands or millions of years, and is not a ‘snapshot’ of behaviour. A concentration of artefacts may be the work of one individual making stone tools over an afternoon, or of multiple visits over generations of different hominins. Furthermore, as these artefacts are not contained within sediments which can be dated, they can often only be assigned minimum ages.
In order to interpret the surface archaeological record therefore, archaeologists must work closely with geomorphologists and geographers in order to understand the ways in which the landscape has developed, what this means for the locations in which we find artefacts today, and what constraints this places on how we interpret these distributions in terms of hominin behaviour.
The SURFACE project combines these archaeological and geomorphological approaches to investigate the surface archaeological record in Southwestern Saudi Arabia, in the regions bordering the Red Sea coast. This region is key in tracing dispersals of populations out of Africa, where many Homo species arose; during periods in which the sea level was lower than today, populations may have crossed between Africa and Arabia across the southern end of the Red Sea. Running from 2016-2018, the project will provide a greater understanding of this key region, and Palaeolithic dispersals through it, as well as developing methods for archaeological survey which can be applied to other regions and records of different time periods.
The project (2016–2018) is hosted by the University of York, UK and Macquarie University, Australia. More about the researchers involved can be found on the People page.