Meet Denny: the teenage girl from Siberia who had a Neandertal Mother and a Denisovan Father

That's a conjectural reconstruction of a Denisovan woman.

In the far east, in the Altai mountains, in the cave where the first Denisovans were found, Russian archaeologists have been hard at work. They found the original Denisovan people there. They found some remnants of Neandertals having come as far East as we have known. They have now found someone quite remarkable: Denny.

What they found was a part of a leg bone. That leg bone belonged to a girl they have nicknamed "Denny." Denny was at least 13 years old. She who had a Neandertal mother and a Denisovan father. That's right. She was a product of two different human species interbreeding. How do they know this?

The Russian scientists sent the bone to Germany for DNA sequencing. There the Germans, who have a lot of experience doing this, found she was a mix of DNA from the Denisovans and the Neandertals. They found her mitochondrial DNA was Neandertal. Mitochondrial DNA is only passed on from mother to child. That meant her mother was a Neandertal. There was even more remarkable family history buried in Denny's DNA.

For one, Denny's dad actually was part Neandertal, too. Much like how we look at bison on the Great Plains of North America as being bison, many of them have cattle DNA from interbreeding with free ranging cattle. Denny's dad had a relatively recent ancestor who was a Neandertal. Likewise, there was evidence of a mystery hominin (species of human) who was a very distant ancestor of Denny's dad. We have no idea who they were, but they were NOT closely related to modern humans, Denisovans or Neandertals.

Denny's mom turned out to NOT be closely related to the Neandertals who had been found in the very same cave. In fact, the Neandertals found in the cave had some traces of having interbred with early modern humans. Denny's mom actually was more closely related to a Neandertal found in Croatia! What does that mean? It's hard to tell. It does mean the local population of Neandertals changed. Whether it was relatives of Denny's mom migrating west or ancestors of Denny's mom having migrated east, we don't know. However, it is wildly clear Neandertals were actually a traveling people. They moved east and west quite a bit and were not merely stuck in local areas as often depicted.

What is really interesting is it appears to have been quite common for Neandertals and Denisovans to have interbred. It might not have happened often: Denisovans and Neandertals lived in a world with far, far less people in it than today, or even has existed since before the beginning of agriculture. However, when they did meet, it shacking up most definitely happened. This makes it far less surprising modern people and other hominin, or human, species were interbreeding. It seems to have been happening a very, very long time ago and even when modern humans were not present.

Ancient DNA reveals tryst between extinct human species
http://science.sciencemag.org/content/361/6404/737

Neandertal mother, Denisovan father!
https://www.eurekalert.org/pub_releases/2018-08/mpif-nmd082018.php

Mum’s a Neanderthal, Dad’s a Denisovan: First discovery of an ancient-human hybrid
https://www.nature.com/articles/d41586-018-06004-0

The genome of the offspring of a Neanderthal mother and a Denisovan father
https://www.nature.com/articles/s41586-018-0455-x

Genome study of cave bones reveals early human hybrid
https://newatlas.com/neanderthal-denisovan-hybrid/56022/