Modern humans and Neanderthals were interacting 100,000 years earlier than previously thought, according to researchers who used CT scans and 3D mapping to study the bones of a child believed to be the result of interbreeding between the two groups. The child, described in a study published in the peer-reviewed journal L’Anthropologie, was buried in a cave in Israel some 140,000 years ago.
Because no ancient DNA was extracted from the fossilised remains, it is impossible to confirm the child's origins. However, scientists say microscopic details in the bones indicate the child had traits of both Homo sapiens and Neanderthals. When the bones were first excavated from Skhul Cave in northern Israel in 1931, archaeologists recognised that the child belonged to neither group and concluded it was a separate species indigenous to the area.
The new 3D mapping allowed researchers to study small details of the skull that had previously been difficult to decipher, such as the construction of the inner ear and the imprint of blood vessels that supplied the brain. By comparing known characteristics of both groups, the researchers concluded the child was the result of interbreeding. Previously, the earliest known example of interbreeding was around 40,000 years ago in central Europe.
Israel Hershkovitz, lead researcher and professor of archaeology and human evolution at Tel Aviv University, said: “What we’re saying now is that there was an extensive relationship between Homo sapiens and Neanderthals that started around 140,000 years ago, and the two groups managed to live side by side with no evidence for hostile encounters.” The interbreeding and shared cultural practices challenge the notion of Homo sapiens as intolerant to other human groups.
Without DNA, it is impossible to prove the child was a hybrid, said Pascal Gagneux, an evolutionary biologist at the University of California San Diego not involved in the research. Still, he said, details revealed by the mapping support the hybrid hypothesis. The virtual model allowed analysis of tiny details, including blood vessel imprints, which are distinct between the two groups due to different brain shapes.
The technology also offers archaeologists a fresh opportunity to review conclusions from objects excavated many years ago. Skhul Cave is one of three caves in the region representing some of the oldest known intentional burials, dating to more than 100,000 years ago.
