A team of scientists from the Max Planck Institutes for Chemical Ecology and the Science of Human History has discovered what they believe to be the first human footprints in Saudi Arabia, a crossroads of the world that plays a key role in understanding how humans abandoned their African homeland and began to colonize the rest of the world. Researchers date these footprints to around 120,000 years and are located where there was once an ancient lake (called Alathar, which means ‘the trail’ in Arabic) in today’s El Nefud Desert (northern Saudi Arabia), a region crucial in the migration of humans out of Africa and to the rest of the world, as it served as a gateway between Africa and Eurasia.
Apart from drawing a scene in which Homo sapiens would have stopped to drink and look for food, the place was also frequented by camels, buffalo, hippos and large elephants according to the traces found. A unique ecosystem in what is now a vast and arid desert 290 kilometers long.
But it is clear that this was not always the case: due to the natural variation of the climate, this area experienced much greener and wetter conditions in a period known as the last interglacial.
“Only after the last interglacial, when the colder conditions returned, is there evidence that Neanderthals moved through the region. These footprints therefore probably represent Homo sapiens,” explains Mathew Stewart of MPI-CE, co-author. of the work published in the journal Science Advances.
The researchers found a total of 376 tracks , including those of 7 hominids, 44 elephants and 107 camel tracks. At approximately 120,000 years old, these fossils appear to be the oldest human footprints outside of Africa. The footprints were dated using a technique called optically stimulated luminescence: shooting light at the quartz grains in the sediments and measuring the amount of energy emitted by them. They act like a ‘natural clock’, according to experts.
The tracks were discovered in 2017 when erosion removed the sediment that settled on the tracks, exposing them to view.
“We know that humans were visiting this lake at the same time as these animals and, unusually for the area, there are no stone tools,” Stewart continued. According to the work, it would be modern humans and not Neanderthals, by height estimates and mass and also because it is not known that these were in the Middle East at that time.
A journey through a green Arabia
Experts previously believed that humans made this journey along coastal routes, but this study shows that it may not necessarily be true. They theorize that instead of following the ocean, humans could have taken inland routes and followed lakes and rivers.
“The presence of large animals such as elephants and hippos, along with open grasslands and large water resources, may have made North Arabia a particularly attractive place for humans moving between Africa and Eurasia,” says Michael Petraglia, co-author of the study.
Referencia: M. Stewart el al., “Human footprints provide snapshot of last interglacial ecology in the Arabian interior,” Science Advances (2020). advances.sciencemag.org/lookup … .1126/sciadv.aba8940
