Over recent years, advances in ancient genomics and archaeology have revolutionized the story of the first human settlers in Europe. Previous studies have shown that the earliest human ancestors in the continent appeared 45,000 years ago and had relationships with the Neanderthals before vanishing some 5,000 years afterward.


(Photo: Wikimedia Commons/ Andrew Curtis)

Cosmic Clock

Archaeologists discovered stone tools in a quarry in Korolevo, western Ukraine, during the 1970s. The site lies close to Ukraine's southwestern border with Hungary and Romania.

Experts have recovered 90,000 chipped stone tools that seemed to have been deliberately fashioned from volcanic rock, an indication of human intervention. Initial dating of the archaeological site suggests that the stones had been used for over 800,000 years.

A team of archaeologists from the Czech Academy of Sciences in Prague recently conducted a fresh dating analysis of the artifacts. Compared to the initial dating method, the new study involves a more accurate way of determining the ages of the artifacts in the lowermost archaeological layer.

The research team, led by Roman Garba, analyzed radioactive particles inside mineral grains produced by cosmic rays. These charged particles serve as a cosmic clock that unleashes human history.

Cosmic rays travel through space and rain down on our planet. As they interact with the Earth's atmosphere, the shower of radiation penetrates rock and creates cosmogenic nuclides or isotopes. These rocks are protected from isotopes when they get buried since the nuclides cannot form below the surface of the Earth. The decay rate of these isotopes is measured to determine the time the previously exposed rock has been shielded from cosmogenic nuclide.

In a recent study, Garba and his colleagues measured two nuclides: aluminum-26 and beryllium-10. These isotopes are found in quartz grains from seven pebbles unearthed in the same layer as the stone tools. After using two calculation methods, the researchers determined that the artifacts were 1.4 million years old.

READ ALSO: Ancient Skull Fragments Discovered in Ukraine Suggests Early Modern Humans in Europe Descended From the East

Early Hominins in Europe

No human fossils have been found at the archaeological site so far. Since it is an open-air area, the exposed conditions make it harder for fossils to be preserved. The acidity of the soil also accelerates the decomposition of artifacts.

According to Garba, it is not clear what species of early humans occupied the site at that time, although the study suggests that it would have been Homo erectus. Archaeologists believe that the extinct human species were the first hominin to have left Africa and walk with a fully upright posture.

The earliest human fossils discovered in Europe are from the Atapuerca site in Spain and are considered 1.1 million years old. Human fossils were also found in Georgia near Dmanisi, believed to be 1.8 million years old. Ukraine's newly dated stone tools fill a gap in early hominin presence in Europe regarding time and space.

The findings from this study suggest that the first human settlers in Europe made their way from east to west. Hominins were also believed to inhabit higher latitudes of northern Europe before colonizing the southern region.

Garba and his team plan to continue their investigation of Korolevo. Unfortunately, Russia's war in Ukraine makes it difficult for them to excavate and access artifacts from the site.

RELATED ARTICLE: DNA Shows Early European Migrants Regularly Interbred with Neanderthals

Check out more news and information on Ancient Europe in Science Times.