When a Neanderthal meets a Denisovan…
You may have heard that late this August paleogeneticist Viviane Slon made an earth-shattering discovery. What was it? Well, while investigating a 90,000+ year old flake of bone from a teenager she discovered her parentage was incredibly unique. She has a neanderthal mom...and a Denisovan dad.
Before we dive into what this means...what exactly is a Denisovan? They are an extinct species of hominid and are a close relative of modern humans. However, they are a new kind of hominid. We didn’t even know about them until 2010 when remains were discovered in a cave in Siberia! It is believed they were spread from Siberia to Southeast Asia and existed around the last Ice Age.
Okay, now back to why it is important that we have found evidence of a Denisovan procreating with a Neanderthal! Well, first of all, this teenage girl is the first known offspring of parents from two different branches of the human family tree. Before this, it was only speculated that different branches may have procreated.
Slon was so shocked when she received the results of the girl’s parentage she immediately thought she had made a mistake or that the sample may have become contaminated. So, she tested it again...and again...and again. In total, she tested the fragment six times and each time the results came out the same.
The bone fragment in question is from that same cave where Denisovans were first discovered. We know that the girl was about 13-years old and that her father was a Denisovan and her mother was a Neanderthal and that the bone fragment likely comes from her arm or leg. According to National Geographic, “ the fragment is unrecognizable as a hominin bone at first glance. Because of this, it was initially cast aside for later analysis with thousands of other pieces of bone found in the cave, including fossils from lions, bears, hyenas, and more.” However, years later it was discovered to be hominid and found its way to Slon.
The study based on the bone published in Nature last month suggests that past interbreeding not only existed without a doubt, but that it might have been even more common than scientists initially thought. Further research shows that the father of this teenager shows traces of Neanderthal relatives as well, suggesting that his offspring was not the first product of inbreeding by a long shot.
Emili Huerta-Sanchez, a population geneticist at Brown University, notes “This paper and other papers are showing the model of having isolated populations is not quite accurate… “These other groups that coexisted with us . . . are part of our story,” she said. It is interesting to note that Huerta-Sanchez is among the scientists who do not consider Neanderthals, Denisovans and modern humans separate species.
This discovery is new and while it is changing the way we will look at human evolution, analysis and research is still on-going. For example, we are not sure if the procreation between Neanderthals and Denisovans were peaceful or if they were violent. Did they wipe each other out? Or did they peacefully blend together until they eventually became part of the current human tapestry?
Whatever happens, you can be certain I’ll be following this story and its updates closely!
Replica of a Denisovan finger bone fragment, originally found in Denisova Cave in 2008, at the Museum of Natural Sciences in Brussels, Belgium. Please note this is NOT the bone shard of the young girl, just a similar find.