8 million years ago, the Arabian Peninsula was green: Fossils and caves change the history of human migration
A new study published in the journal Nature reveals that the desert region now known as the Sahrawi Desert, which stretches from Africa to Saudi Arabia, was not always hot. A study funded by the Saudi government found that over the past 8 million years, the region has undergone several sustained wet periods during which rivers flowed and natural lakes formed, allowing for animal migration and even early human settlement.
The researchers, an international group led by a team from Australia's Griffith University, have found evidence that the Arabian Peninsula once served as a greenway - a natural corridor connecting Africa and Eurasia. Today, the desert is a huge natural barrier that prevents the free movement of species and populations, but new scientific history suggests that millions of years ago the region was a key center for species exchange and large-scale biogeographical connections.
Professor Michael Petrahlia, director of the European Research Centre for Human Evolution at Griffith University and a co-author of the study, notes that fossil evidence from the late Miocene (a period characterised by rising global temperatures) and Pleistocene (a period of several ice ages) indicates the presence of water-dependent animals in the heart of the desert. He adds: "The findings suggest that the humid conditions of those times facilitated the dispersal of mammal species between Africa and Eurasia, with the Arabian Peninsula serving as a key junction for rapid biogeographical exchanges."
Alongside him, Dr. Monika Markowska from Northumbria University in the UK and Dr. Hubert von-Hoff from the Max Planck Institute for Chemistry in Germany, conducted a new study on mineral levels in caves (stalactites and stalagmites) that indicated recurring wet periods in the region over the past 8 million years. Dr. Markowska, who was the lead author of the article, explains that until now little was known about the ancient climate of the Arabian Peninsula, and the study revealed that the amount of precipitation during wet periods decreased and became unstable over time, as the influence of the weak monsoon and icy conditions in the Northern Hemisphere intensified during the Pleistocene.
In addition, Dr. Faisal Al-Jibreen, the Saudi Chief Archaeologist for the World Heritage Commission, noted that until now the Arabian Peninsula has been neglected in studies of the distribution between Africa and Eurasia, but studies such as this clearly show that the region has a central place in the history of migration of mammals and humans. He emphasized that understanding climatic changes and ecological processes in the region can shed new light on the routes along which ancient human groups migrated, thereby helping to deepen our understanding of human history.
The study raises further questions about the effects of changing climate on species evolution and regional distribution, and suggests that the landscape of the Arabian Peninsula has been changing dynamically over millions of years. The findings challenge the previous hypothesis that the desert remained virtually unchanged for 11 million years, and highlight the need to reexamine the geological and ecological processes of the region.
In conclusion, the study highlights the importance of the Arabian Peninsula as a green corridor and a hub for species exchange between continents, and offers a new framework for understanding human migration and climate change in desert regions. These discoveries may change our perspective on the links between environmental conditions and human and animal development in fractured regions that are currently considered infertile.
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