A group of scientists said Wednesday that a 90,000-year-old bone fragment found in Siberia shows signs of crossing between Neanderthals and another prehistoric group of human family members known as Denisovans.

Although genetic studies in the past have shown signs of crossbreeding between the two groups, but also with homo sapiens, Wednesday's study is the first to identify a child of the first generation with Neanderthal and Denisovan parents.

Scientists nicknamed the inter-kind love child Denny, to her Denisovan father.

"It is fascinating to find direct evidence of this mix," said Svante Paabo, a geneticist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and one of the lead authors of the study.

Miracle discovery

The cave where the bone was found, located in the Siberian Altai Mountains near the border with Mongolia, contains the petrified remains of Neanderthals and Denisovans. Finding a direct offspring from the two groups turned out to be a stroke of luck. Only 24 early human genomes older than 40,000 years have been sequenced, which means that the chance that a semi-semi-hybrid is detected is virtually zero.

"The fact that we bumped into this makes you wonder if the mixing does not occur often," said Paabo. "If it had happened more often, we would not differ so much between the Denisovans and Neanderthals."

Both groups disappeared 40,000 years ago. Neanderthals lived in Europe and Asia, while fossils of Denisovans have so far only been discovered in the Siberian cave where the fragment was found.

Scientists said that the old woman's DNA showed that the genes she inherited from her mother were very similar to those of Neanderthals in Europe, rather than those in the cave, suggesting a wave of westward migration.

Today, about two percent of the DNA in non-Africans around the world comes from the Neanderthal ancestors of man. Remains of Denisovan DNA are also widespread, albeit less evenly. Traces of less than 1 percent have been found among Asians and autochthonous Americans, while Aboriginal Australians and people in Papua New Guinea have about five percent, according to Paabo.

This story was originally published on DW.com. Its content is made separate from the US TODAY.

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