For a long time, the last Neanderthals in Europe were pictured as a genetically diverse bunch, scattered across the continent right up until they disappeared. New DNA evidence tells a very different story. Researchers have found that Neanderthals actually went through a severe population crash around 75,000 years ago, one so extreme that only a single surviving group in what is now southwestern France seems to have repopulated the rest of Europe afterwards. This means almost every late Neanderthal we know about, all the way from Spain to the Caucasus, traces back to that one small, surviving population rather than a patchwork of separate groups.
A near-extinction event 75,000 years ago
The research was led by Professor Cosimo Posth at the Senckenberg Centre for Human Evolution and Palaeoenvironment at the University of Tübingen, and it paints a clear picture of what happened to Neanderthals as harsh Ice Age conditions set in. Around 75,000 years ago, archaeological sites across Europe became fewer and clustered more tightly into the southwest of the continent, while genetic diversity among Neanderthals dropped sharply at the same time. This pointed to a genuine bottleneck, a moment when Neanderthal numbers shrank drastically, and only a small pocket managed to hang on.
Why mitochondrial DNA was the key to this discovery
To piece this history together, researchers turned to mitochondrial DNA extracted from Neanderthal teeth and bones found in caves and rock shelters. Mitochondria are tiny structures inside cells that help generate energy, and they carry their own separate strand of DNA, passed down differently from the DNA found in a cell’s nucleus. According to Charoula Fotiadou, first author of the study, mitochondrial DNA does not hold nearly as much information as a full genome, but it tends to survive far longer and is much easier to extract, which makes it especially useful for working with rare and badly degraded ancient remains.
Ten new individuals add to the genetic picture
For this study, Fotiadou and her colleagues sequenced mitochondrial DNA from 10 previously unstudied Neanderthal individuals, recovered from six archaeological sites across Belgium, France, Germany and Serbia. This data was then compared against 49 previously published Neanderthal mitochondrial samples, giving researchers a much larger picture to work with than earlier studies had access to. The genetic results were also paired with archaeological records pulled from ROAD, a major database tracking Neanderthal presence across Europe, allowing the team to map out both where and when key population changes actually took place.
One surviving lineage repopulated the whole continent
According to Posth, the combined evidence shows Neanderthals retreated into what is now southwestern France during this difficult period, and around 65,000 years ago, a new population emerged from that refuge and gradually spread back out across Europe. This explains why nearly every late Neanderthal sequenced so far, regardless of where their remains were found, carries the same inherited mitochondrial DNA lineage. In other words, the Neanderthals who lived across Europe in its final tens of thousands of years were not the descendants of many separate surviving groups, but largely the offspring of this one population that made it through the earlier crisis.
A second sharp decline before extinction
The story does not end there either. Researchers also found evidence of another steep population drop around 45,000 years ago, with Neanderthal numbers falling quickly and hitting their lowest point around 42,000 years ago, shortly before the species disappeared entirely. When the team tested whether Neanderthal genetic diversity matched what you would expect from a population that had simply stayed a steady size over time, the numbers did not add up, strongly suggesting a real and rapid decline rather than a stable population quietly fading out.
Why low genetic diversity may have doomed the Neanderthals
Posth points out that this leaves late Neanderthals looking like a remarkably uniform group genetically, and that this lack of diversity, combined with growing isolation between small surviving groups, may have played a real role in their eventual extinction. A population with little genetic variation tends to be less adaptable when conditions change, since there is less natural variation for evolution to work with if new pressures come along. The full findings, published in the journal Proceedings of the National Academy of Sciences.
Why this discovery matters for understanding Neanderthal extinction
This research fills in a genuinely important gap in the Neanderthal story. Scientists have long known Neanderthals lived continuously across Europe for hundreds of thousands of years before vanishing around 40,000 years ago, but the specific details of their final population history had remained frustratingly incomplete due to scattered and limited evidence. By combining detailed genetic data with a large archaeological database, this study offers one of the clearest pictures yet of exactly how Neanderthal populations rose, crashed and rose again in their last tens of thousands of years on the continent, right before modern humans became the only hominin left standing in Europe. Go to Source
