Study Reveals Late European Neanderthals Descended from a Single Ice Age Survivor Group
Genetic analysis indicates that late European Neanderthals originated from a single group that survived the Ice Age, leading to low genetic diversity before their extinction.
Recent research combining DNA analysis and archaeological evidence has uncovered that the last Neanderthals in Europe descended from a single group that endured the harsh conditions of the Ice Age. This study, published in the journal PNAS, reveals that late Neanderthals shared a largely uniform gene pool before their extinction around 40,000 years ago.
The international team, led by Professor Cosimo Posth at the Senckenberg Centre for Human Evolution and Palaeoenvironment at the University of Tübingen, traced the genetic history of European Neanderthals. Their findings suggest that approximately 75,000 years ago, a localized group survived severe climatic conditions by retreating to a glacial refugium in what is now southwestern France. Descendants of these survivors then spread across Europe after 65,000 years ago.
"Our data enabled us to reconstruct geographically that Neanderthals retreated to what is now southwestern France," explained Professor Posth. "There, around 65,000 years ago, a new population emerged and later spread across the whole of Europe. This explains why almost all Late Neanderthals sequenced so far—from the Iberian Peninsula to the Caucasus—belong to the same line of inherited mitochondrial DNA."
To uncover this history, researchers focused on mitochondrial DNA, which is inherited maternally and often survives longer than nuclear DNA. The team sequenced mitochondrial DNA from ten Neanderthal individuals across archaeological sites in Belgium, France, Germany, and Serbia, analyzing these alongside 49 previously published samples.
The study also indicates that the harsh climatic conditions around 75,000 years ago led to a significant reduction in genetically diverse Neanderthal populations. Archaeological evidence shows a decline in site numbers, with remaining populations becoming concentrated in southwestern Europe. This genetic bottleneck resulted in low genetic diversity among Neanderthals, which may have contributed to their eventual extinction.
"Genetically speaking, the Late Neanderthals were a very homogeneous group," noted Professor Posth. "So it may be that the low genetic diversity—and possibly also the subsequent isolation of small groups—contributed to the disappearance of the Neanderthals."
While most late Neanderthals belonged to this single lineage, rare exceptions have been identified. For instance, an individual nicknamed Thorin, found in Grotte Mandrin in France and dated to about 50,000 years ago, belonged to an older lineage that had been isolated for millennia. However, such cases remain exceptions rather than the norm for late European Neanderthals.
These findings provide a clearer picture of the evolutionary developments preceding the extinction of Neanderthals, highlighting the impact of climatic events on their genetic diversity and survival.