Humans and Neanderthals Lived Side by Side in Northern Europe 45,000 Years Ago, Study Finds

Modern humans had already settled in northwest Europe thousands of years before Neanderthals vanished forever in the southwest of the continent, according to the results of a recent excavation in Ranis, Germany. The new findings offer unprecedented insight into the two species’ interaction, suggesting they lived side by side and might have even interbred.

At the base of a medieval castle, 24 feet deep into the layered sediment of the Ilsenhöhle cave, scientists unearthed leaf-shaped spear points, animal remains and 13 bone fragments identified as early modern humans—evidence that Homo sapiens existed in northern Europe 45,000 years ago.

“Because of the age of this site and location, we know Neanderthals and humans quite definitively had a large overlap,” says study co-author Elena Zavala, a paleo and forensic geneticist at the University of California, Berkeley, to NBC News’ Evan Bush.

The findings, detailed in three papers published Wednesday in the journals Nature and Nature Ecology & Evolution, suggest Homo sapiens journeyed across the European continent much earlier than previously thought. These early humans were capable of withstanding the frigid climate of northern Europe and constructing spear-shaped tools, based on the new discoveries. 

“The Ranis Cave site provides evidence for the first dispersal of Homo sapiens across the higher latitudes of Europe. It turns out that stone artifacts that were thought to be produced by Neanderthals were, in fact, part of the early Homo sapiens toolkit,” says Jean-Jacques Hublin, a study co-author and paleoanthropologist at the Max Planck Institute for Evolutionary Anthropology, in a statement. “This fundamentally changes our previous knowledge about the period: Homo sapiens reached northwestern Europe long before Neanderthal disappearance in southwestern Europe.” 

Researchers used genetic analysis of mitochondrial DNA to confirm the bone fragments found in Germany—some from new findings and others from decades-old excavations—did, in fact, belong to early modern humans. Some of the mitochondrial DNA, which is inherited through the mother, seemed to match, suggesting some bones—even those from older excavations—belonged to the same individual or people related through the mother’s line.

Inspection of nearby animal teeth and bones revealed that these early humans existed amid a harsh, tundra landscape populated by reindeer, cave bears, horses and woolly rhinoceros in conditions comparable to modern Siberia or northern Scandinavia. 

“Until recently, it was thought that resilience to cold-climate conditions did not appear until several thousand years later, so this is a fascinating and surprising result,” says Sarah Pederzani, an archaeologist at the University of La Laguna in Spain who led the paleoclimate study of the site, in the statement. “Perhaps cold steppes with larger herds of prey animals were more attractive environments for these human groups than previously appreciated.”

The study also presents possible answers to age-old questions regarding stone tool manufacturing styles of the period. The leaf-shaped spears found at the site are similar to tools unearthed in Moravia in the Czech Republic, as well as Poland, Germany and the United Kingdom. These were thought to be produced by the same culture, referred to as the Lincombian-Ranisian-Jerzmanowician (LRJ). For years, scientists have been unsure whether these tools were devised by Neanderthals or Homo sapiens. The new findings point to the latter.

“The common wisdom was these transitional assemblages of artifacts were made mostly by late Neanderthals,” Hublin tells Live Science’s Charles Q. Choi. “What we find with the LRJ is that it was not made by Neanderthals, but by Homo sapiens moving into Europe much earlier than we thought.” 

Neanderthals, our closest ancient human relatives, faded into extinction approximately 40,000 years ago. The new research suggests that, contrary to some popular theories, Homo sapiens did not overtake Neanderthals in Europe in one large sweep, but rather ventured into new territory and gradually replaced the species through “successive pulses of small groups,” says Hublin to Live Science. “We see Homo sapiens colonized the northern part of Europe first and lived there for several millennia on the periphery of the Neanderthal world.”

“These groups are exploring,” says John Hawks, a University of Wisconsin–Madison anthropologist who was not involved in the study, to NBC News. “They’re going to new places. They live there for a while. They have lifestyles that are different. They’re comfortable moving into areas where there were Neanderthals.” 

Building upon existing genomic evidence of occasional interbreeding between Homo sapiens and Neanderthals, the next phase of investigation is to determine the extent to which the two groups crossed paths—perhaps by looking for Neanderthal DNA in the newly unearthed bone fragments.

Getting this evidence could move researchers one step further in understanding the Neanderthals’ demise—and reveal insights about our own existence. 

“It goes after this question—what makes us human? One thousand years ago, throughout the globe, there were multiple kinds of hominins on the planet,” Zavala tells NBC News. “Now, it’s just us. Why did that happen? How did evolution get to where we are, and what does that mean for our future?”

Catherine Duncan | READ MORE

Catherine Duncan is an intern with Smithsonian magazine.