We know that modern humans and Neanderthals interbred, leaving a genetic legacy in our DNA, but pinpointing the exact locations and times of these encounters has been a challenge. Now, a groundbreaking study offers a new perspective, identifying the Zagros Mountains in present-day Iran as a likely hotspot for these ancient interactions.
The Zagros Mountains, a rugged and mountainous region, have long been considered a crucial crossroads in human migration. According to Saman Guran, lead author of the study and an archaeologist at the University of Cologne, this region served as a transition zone between the warmer ecosystems favored by early modern humans and the colder climates that suited the Neanderthals.
Neanderthals, who emerged around 400,000 years ago, thrived in Europe and Asia, while the ancestors of modern humans evolved in Africa around 300,000 years ago and eventually spread across the globe. Genetic evidence indicates that Neanderthals and Homo sapiens interacted multiple times — around 250,000 to 200,000 years ago, between 120,000 and 100,000 years ago, and finally, around 50,000 years ago — before Neanderthals ultimately vanished as a distinct population.
While the Middle East was long suspected as a prime meeting ground for these two groups, a lack of ancient human and Neanderthal remains from this area has hindered concrete proof. To overcome this challenge, the research team devised an ecological model, combining geographic data on Neanderthal and human archaeological sites to pinpoint the most likely areas of overlap during the second wave of interbreeding, estimated to have occurred between 120,000 and 80,000 years ago.
Their findings, published in the journal Scientific Reports, point to the Zagros Mountains as the ideal meeting place. This region, stretching for 990 miles (1,600 kilometers) and primarily located in Iran, is part of the Persian plateau, which recent discoveries have revealed as a significant “hub” for Homo sapiens around 70,000 years ago. The Zagros Mountains offered diverse ecosystems capable of supporting both Neanderthals and modern humans.
Further supporting the study’s findings, Shanidar Cave, one of the most significant Neanderthal sites ever discovered, is situated within the Zagros Mountains. Excavations have unearthed ten skeletons within the cave, several exhibiting evidence of injuries, while others provide strong evidence that Neanderthals buried their dead. Despite the significance of Shanidar Cave, much of the Zagros area remains unexplored.
“Archaeological data in this area is very poor,” acknowledges Guran, highlighting the need for further research. “We have plans to get better evidence,” he adds, emphasizing the importance of discovering physical human remains from archaeological excavations, along with stone tools and accurate dating information.
The researchers’ ecological model, considering factors such as temperature and precipitation, adds valuable context to the archaeological and genetic evidence of Neanderthal-human interaction. Leonardo Vallini, a molecular anthropologist at Johannes Gutenberg University in Mainz, Germany, who was not involved in the study, notes that the model “is a nice confirmation that the area could have played a crucial role in the earliest part of Homo sapiens’ expansion into Eurasia.”
This type of modeling offers promising avenues for future archaeological research, providing valuable insights into the history of human evolution and dispersal. The researchers encourage Iranian archaeologists to actively investigate the Zagros Mountains, anticipating exciting discoveries that will shed light on our complex and fascinating evolutionary past.
