Monday, April 29, 2019
The First Confirmed Hominin Hybrid Has Been Discovered
Denisova 11, as she is called, was an approximately 13-year-old girl who lived around 90,000 years ago in the Altai Mountains of Siberia. What is so fascinating about this girl is that she is clear evidence for interbreeding between species in the genus Homo (humans). She is indeed about half Denisovan and half Neandertal, two early members of the genus that are related to Homo sapiens.
Viviane Slon, a researcher at the Max Planck Institute in Leipzig, Germany, performed DNA analysis six times on Denisova 11's piece of limb bone that had been found. She simply could not believe the results of the analysis the first time and had thought she made a mistake. However, each successive test came to the same conclusion. This young girl had a Neandertal mother and a Denisovan father. Moreover, they discovered that her father in fact had a Neandertal ancestor of his own. This was further confirmation of how common hybridization must have been in early hominins.
So far, only Denisova 11 and four other individuals belonging to the species Homo denisova have been uncovered by the bone fragments that they left behind in a single cave in the Altai Mountain range. As I have previously reported, the species was first identified in 2010, when DNA sequencing of the toe bone of an individual called Denisova 3 led scientists to confirm the existence of an entirely new group of humans.
Svante Pääbo, the director of the Max Planck Institute of Evolutionary Anthropology, has stated that due to the fact that Neandertals originated in western Eurasia and that Denisovans originated in the east, they likely did not meet very often. But based on these latest findings, Pääbo and many other scientists now believe that when the two species did come face to face, mating between them was far more common than was ever previously thought.
The idea that Denisovans, Neandertals, and Homo sapiens were producing hybrids for possibly hundreds of thousands of years is supported by genetic studies of modern populations. The DNA of people living in Europe and Asia today is on average 2% Neandertal. The DNA of people living in Melanesia today is on average 5% Denisovan, with other varying amounts found in the rest of southeast Asia and Oceania.
The genomes of all these humans studied, ancient and modern, reveal that hybrids were not uncommon throughout our shared history on this planet.