Bones in German cave show humans were in Europe long before previously thought

Ancient bones found in a cave in northern Germany prove what scientists have long suspected: Humans and our Neanderthal cousins lived alongside each other for thousands of years in northern Europe.

That is according to a groundbreaking trio of papers from Nature and Nature Ecology and Evolution — studies that push back the earliest date of Homo sapiens’ expansion into northern Europe to 45,000 years ago, far earlier than had previously been confirmed.

“These are among the earliest Homo sapiens in Europe,” said Elena Zavala, co-author of the Nature paper and a research fellow at the University of California, Berkeley.

The findings also add support to a darker corollary to the long-running theory of Homo sapiens’ and Neanderthals’ coexistence in the area: It was the human invasion that drove the Neanderthals to extinction after their 500,000-year hegemony in Europe.

Research from genomics suggests the only survivors of this great extinction event may have been Homo sapiens themselves, whose genes bear the traces of past couplings with Neanderthals.

The new findings connect the dots between archaeological and genomic evidence, allowing scientists to correlate a specific style of weapon found across Europe with the bones of its likely creators.

Those bones were pulled from a cave near Ranis, Germany, one of Europe’s richest lodes of leaf points, which are a type of stone spear blades.

Finds from this site have “fundamentally changed our ideas about the chronology and settlement history of Europe north of the Alps,” said Tim Schüler, who works in historical preservation for the German state of Thuringia.

The Ranis site seems to have been only occasionally occupied by humans; most of the bones at the site were from species such as bears and hyenas.

For decades, scientists had been unsure who made the blades found there.

Known as “leaf points” for their characteristic shape, these blades have been found from the U.K. to Poland and had long been thought to be characteristic of Neanderthal technology.

In part, this was because scientists had assumed that Neanderthals — a closely related type of hominid that arrived in Europe half a million years before Homo sapiens — at that point had Europe to themselves.

But the discovery of fragments of bones from Homo sapiens alongside leaf points calls that interpretation into question, and the Nature authors suggest the cave was the last resting place for members of small pioneer groups of modern humans pushing into the frigid country north of the Alps.

Determining that those bones belonged to Homo sapiens required scientists to dig deeper than past research teams: both literally, into older layers of the cave, and using new methods of genomic analysis.

Because the fragments were so small, scientists couldn’t get intact nuclear DNA, the kind we generally think of when we think about our own genetic code.

Instead, they had to sequence the distinct genetic information carried within mitochondria — energy-generating “power plants” within cells that have kept their own genetic records, and controlled their own reproduction, for the 1.5 billion years since they merged with ancient hosts to form the cells that are the basis of complex life.

Unlike nuclear DNA, which preserves records of both parents, mitochondrial DNA only traces the maternal line — and that led scientists to a new discovery: Many of these bone fragments came from relatives of people whose remains had previously been identified.

In addition to being related to each other through the maternal line, 12 of the 13 individuals found at Ranis appeared to be related to the 43,000-year-old skull of a woman found in a cave in what is now the Czech Republic — suggesting the Ranis people were her long-lost relatives.

And the one fragment that did not match the others did match with a Homo sapiens skeleton found in Italy.

“That raises some questions: Was this a single population? What could be the relationship here?” Zavala said.

“But with mitochondrial DNA, that’s only one side of the history. It’s only the maternal side. We would need to have nuclear DNA to be able to start looking into this.”