The human family tree is becoming messier than The Jerry Springer Show. We already know Homo sapiens and Neanderthals slept together. We also know both slept with the mysterious “Denisovan,” a human relative first identified in Siberia’s Denisova Cave in 2010. Now, researchers have discovered that Neanderthals and Denisovans were shacking up in that same Siberian cave for tens of thousands of years.
Two studies published in January 2018 in Nature paint a fuller picture of what was going on in the high-ceilinged love getaway nestled in Russia’s Altai Mountains. Archaeological evidence from the cave suggests Denisovans moved in about 287,000 years ago, much earlier than previously thought. Neanderthals seem to have joined the Denisovans in the cave about 193,000 year ago and lived with them for nearly 100,000 years.
These Neanderthals and Denisovans were more than just roommates. Last year, researchers tested the remains of a 13-year-old girl who lived in the cave and discovered she had a Neanderthal mother and a Denisovan father. Some archaeologists think Homo sapiens—the only surviving type of hominin—may have lived in the Siberian cave at some point, too, based on a mystery the new Nature studies raise.
The Nature studies suggest Denisovans left the cave around 55,000 years ago, long after the Neanderthals had moved out. Yet even after both groups were supposedly gone, archaeologists have found artifacts in the cave that date to between 43,000 to 49,000 years ago. These ornaments made of bone, animal teeth, mammoth ivory and ostrich eggshell resemble modern human artifacts found elsewhere. But so far, archeologists haven’t found any Homo sapien remains in the cave.
As Kate Wong, a senior editor at Scientific American, points out in a Twitter thread, this raises an intriguing question—did the Denisovans have our skills?
“Not so long ago standardized bone tools and symbolic items such as jewelry were seen as markers of modern human cognition and behavior, exclusive to members of our own species,” tweeted Wong, who also wrote about the new cave research in Scientific American. “In recent years it has become clear that Neandertals made such items… The possibility that Denisovans, too, developed symbols and complex tools, further complicates the picture.”
If Denisovans did make these artifacts, that would raise even more questions. For example, did Denisovans develop the skills to make ornaments independently, or learn these skills from someone else? It’s possible many hominin communities developed these skills independently at different points in history. But it’s also possible that modern humans learned some of their skills from hominins that are now extinct.
The 2010s have been packed with discoveries showing ancient Homo sapiens weren’t as far ahead of everyone else as we thought. Archaeologists have identified a 500,000-year-old shell engraved with geometric designs that predates both modern humans and Neanderthals. This means its designer must have been a more ancient human ancestor like Homo erectus, the “upright man.”
Neanderthals in particular are raking in the good publicity. Researchers have determined that Neanderthals in France knew how to create fire 50,000 years ago, which is earlier than any evidence we have for modern humans. They’ve also discovered that Neanderthals in Germany 300,000 years ago may have hunted game at a distance by throwing spears.
Without more research, it’s not at all clear who could have made those ornaments in the Siberian cave. For now, we just know the Neanderthal-Denisovan love shack was a little old place where they could get together.