Some 45,000 years ago, in the frigid reaches of Ice Age Europe, a small band of humans trudged across the tundra, their dark skin warmed by fur-lined cloaks. They hunted woolly rhinos, fashioned distinctive stone tools, and perhaps exchanged stories around fires in caves. A new discovery of ancient genomes brings these forgotten ancestors — and their fleeting presence — into clearer view.

Their story, revealed through fossilized remains unearthed in Germany and the Czech Republic, uncovers a surprising twist in the saga of human migration out of Africa.

These genomes are the oldest yet found of modern humans in Europe. Like any good research, these genomes lead to more questions than they answer, deepening the mystery of when, exactly, humans left Africa and how they mingled with our evolutionary cousins, the Neanderthals.

Ancient DNA and a Vanished Legacy

In the cave in Ranis, Germany, archaeologists recovered bone fragments belonging to six individuals — a family that included a mother, her daughter, and distant cousins. The remains, sequenced by researchers at the Max Planck Institute for Evolutionary Anthropology, date back 45,000 years. They are part of a cultural group known as the Lincombian-Ranisian-Jerzmanowician, or LRJ for short.

Here’s where things get really interesting though. About 230 kilometers away, scientists also sequenced the DNA of an ancient woman’s skull from Zlatý kůň, Czech Republic. They found the people from Ranis and Zlatý kůň were related.

“It’s the same group, the same extended family,” said Johannes Krause, a geneticist at the Max Planck Institute, told the NY Times. “It could be that they knew each other.”

Yet these families were few in number — perhaps only hundreds roamed across the vast, inhospitable landscape. Their genetic uniformity hints at isolation.

“If I were to go to New York and just take one person from the Bronx and then go over to Long Island and take another person from there, it would be unlikely that these two have a common ancestor within the last three generations,” said Kay Prüfer, a paleogeneticist and co-author of the study. “But, of course, we are talking about the deep past, when things were different.”

Unlike Europeans today, the LRJ people did not carry genes for pale skin. Their pigmentation remained dark, reflecting their recent origins from Africa. But their time in Europe was short-lived. Although the lineage survived a trip out of Africa and several generations in Europe’s harsh wilderness, their line eventually disappeared — and their DNA left no mark on modern populations.

The Neanderthal Connection

These ancient genomes also reveal a deep connection with Neanderthals. When early humans migrated out of Africa, they encountered Neanderthals who had lived in Europe and western Asia for hundreds of thousands of years. The two groups interbred, leaving a legacy of Neanderthal DNA in our genomes. Just last week, researchers at the Max-Planck-Institute for Evolutionary Anthropology and UC Berkeley showed that Neanderthal and Homo sapiens interbreeding lasted for an estimated 7,000 years.

The LRJ people carried long stretches of Neanderthal DNA, suggesting that their ancestors had interbred with Neanderthals only 1,000 to 2,500 years earlier — about 46,000 years ago. The Max-Planck-Institute for Evolutionary Anthropology study mentioned earlier estimated a similar timeline after studying Neanderthal DNA from fossils and comparing the genetic sequences with living people.

This timing tightens the window for when humans moved from the Middle East into Europe.

“It was really fantastic to see a similar date,” said Priya Moorjani, a paleogeneticist at the University of California, Berkeley, who co-authored the related study.

Intriguingly, while the LRJ people carried Neanderthal ancestry, they did not pass their own DNA to future generations. Their extinction mirrors the fate of the Neanderthals, who vanished around 40,000 years ago.

“It’s kind of interesting to see that human story is not always a story of success,” Krause told CNN.

A Vanishing Branch of Humanity

The discovery of these ancient genomes reshapes our understanding of human migration. While modern humans reached Australia 65,000 years ago and possibly China 100,000 years ago, the LRJ people represent a late wave into Europe. Many such waves probably occurred during humanity’s history of migration out of Africa. Ultimately, some groups were more resilient than others.

This raises a perplexing question: Who were the people who left those older fossils and tools in Asia and Australia?

These revelations highlight how fragile survival was for early humans. Small populations faced extinction, even as others thrived. Some paths vanished in the cold, while others blazed forward, shaping the world we know today.

The new findings appeared in the journal Nature.