Once upon a time, some 50,000 years ago, two early humans met at a cave in Russia. Thanks to present-day scientific research, we now know that they mated and had a daughter together.
What is remarkable about the story is that the baby girl was the offspring of two different species – a Neanderthal mother and a Denisovan father. Both Neanderthals and Denisovans were humans like us, but they belonged to different species, Denisovans being an Asian race. The discovery, published in Nature and reported on the BBC website, gives a rare insight into the lives of our closest ancient human relatives.
Researchers at the Max Planck Institute for Evolutionary Anthropology (MPI-EVA) in Leipzig, Germany, have extracted DNA from bone fragments found in a cave in the Altai Mountains of Siberia. “We knew from previous studies that Neanderthals and Denisovans must have occasionally had children together,” says Viviane Slon, researcher at the Institute. “But I never thought we would be so lucky as to find an actual offspring of the two groups.”
The girl’s story has been pieced together from a single fragment of bone found several years ago in the Denisova cave by Russian archaeologists. The bone was subsequently brought to Leipzig for genetic analysis. “The fragment is part of a long bone, and we can estimate that this individual was at least 13 years old,” says Bence Viola of the University of Toronto. The researchers deduced that the girl’s mother was genetically closer to Neanderthals who lived in western Europe. Genetic tests also revealed that the Denisovan father had at least one Neanderthal ancestor further back in his family tree.
It was already known that Neanderthals and Denisovans lived at the same time in Eurasia until about they died out about 40,000 years ago. Neanderthals lived in the west and Denisovans in the East but clearly they must have had contact with each other. Even today, some humans have a small proportion of Neanderthal DNA and others have traces of Denisovan DNA. The fact that the genes have been passed down through so many generations shows that interbreeding must have happened at some time in the past. However, the only known site where fossil evidence of both Denisovans and Neanderthals has been found is at Denisova cave.
Text Alun Harvey
Source BBC News website