Editor's Note: The story was originally published on 18th September, and has been republished to include new information from agencies and reports.
It is a widely followed belief that all human beings originated in Africa and slowly moved out to different continents via different routes. Now, scientists have come across fossilized footprints of ancient human beings that date back nearly 1,20,000 years in what is now northern Saudi Arabia.
It appears as if a small band of Homo sapiens stopped to drink and forage at a shallow lake that was also frequented by camels, buffalo, and elephants bigger than any species seen today. The human population may have hunted the large mammals in the area, but didn't stay long, using the watering hole as a waypoint on a longer journey. The ancient lake deposit was in Saudi Arabia's Nefud Desert.
If these footprints are confirmed, they will become the oldest sign of humans existing on the Arabian soil. The new findings have been published in the journal Science Advances. Researchers from the Max Planck Institutes for Chemical Ecology and the Science of Human History in Germany and Royal Holloway University of London together with a team of international partners conducted the study.
Fossilized footprints of elephants and horses, among other animals, and seven footprints of ancient human beings have been discovered. Although the Arabian Peninsula exists in the middle of Africa and Eurasia, it has not received much importance in determining the course of human dispersals out of Africa. One of the reasons behind this could be the hyper-arid deserts that have become characteristic of the region. But research has shown that Arabia was not like this in the past and the recent footprints were actually taken from an ancient muddy lakebed. These hundreds of footprints were exposed after the erosion of overlying sediments.
Richard Clark-Wilson of Royal Holloway, one of the lead authors of the study, said in a statement that at certain times in the past "the deserts that dominate the interior of the peninsula [have] transformed into expansive grasslands with permanent freshwater lakes and rivers".
This detailed scene was reconstructed by researchers in a new study published in Science Advances on Thursday, following the discovery of ancient human and animal footprints in the Nefud Desert that shed new light on the routes our ancient ancestors took as they spread out of Africa.
Today, the Arabian Peninsula is characterized by vast, arid deserts that would have been inhospitable to early people and the animals they hunted down. Research over the last decade has shown this wasn't always the case "natural climate variation in the Peninsula once favoured a much greener, more humid environment in a period known as the last interglacial.
"At certain times in the past, the deserts that dominate the interior of the peninsula transformed into expansive grasslands with permanent freshwater lakes and rivers," study co-author Richard Clark-Wilson of Royal Holloway, told AFP. "Footprints are a unique form of fossil evidence in that they provide snapshots in time, typically representing a few hours or days, a resolution we tend not to get from other records."
The prints were dated using a technique called optical stimulated luminescence " where light is blasted at quartz grains to measure the amount of energy they emit from them. In addition to the footprints, some 233 fossils were also recovered. These likely belong to predators of herbivorous animals in savannas, like the African savannas in the modern day.
The new paper demonstrates "inland routes, following lakes and rivers, may have been particularly important to humans dispersing out of Africa" too, the study authors said.
"The presence of large animals such as elephants and hippos, together with open grasslands and large water resources, may have made northern Arabia a particularly attractive place to humans moving between Africa and Eurasia," senior author of the study, Michael Petraglia of the Max Planck Institute for the Science of Human History, told AFP.