A new mathematical model proposes a compelling answer to the mystery surrounding Neanderthal disappearance: maybe they didn’t vanish entirely, but rather blended into humanity through genetic absorption. Instead of succumbing to “true extinction,” this theory suggests that Neanderthals gradually faded away as their genes merged with those of Homo sapiens over thousands of years.
It wasn’t always accepted that Neanderthals and modern humans interbred. However, recent discoveries in genetics and archaeology provide strong evidence that our ancestors were romantically involved across Eurasia for tens of thousands of years. Today, people of non-African descent carry about 1 to 4 percent Neanderthal DNA—a clear testament to this ancient mixing.
The exact reason behind Neanderthals’ disappearance roughly 40,000 years ago remains unclear. While factors like climate change, limited genetic diversity, and competition with our species are likely contributors, a new study offers a different perspective.
Andrea Amadei, a computational chemist at the University of Rome Tor Vergata, along with evolutionary geneticist Giulia Lin from Switzerland’s Federal Institute of Aquatic Science and Technology, and ecologist Simone Fattorini from Italy’s University of L’Aquila, developed a model exploring genetic drift as a major driver.
Their findings suggest that even without any survival advantages conferred by Neanderthal genes, gradual absorption into the larger Homo sapiens population could have led to near-complete genetic assimilation within 10,000 to 30,000 years. Incorporating potential benefits of certain Neanderthal genes would further strengthen this theory.
This model utilizes birth rates observed in modern hunter-gatherer societies to predict how quickly smaller Neanderthal groups would be diluted by the expanding human population—a scenario reinforced by archaeological evidence suggesting a gradual rather than sudden decline of Neanderthals in Europe.
The Intertwining Threads of Humanity and Neanderthal Ancestry
The picture emerging from this research aligns with recent discoveries indicating earlier-than-expected migrations of Homo sapiens out of Africa, potentially beginning over 200,000 years ago. Each wave of migration would have interacted with existing Neanderthal populations, leading to genetic blending akin to sand being absorbed into a vast ocean.
Some scientists are pushing the notion that Homo sapiens and Neanderthals were not distinct species but rather different populations within a broader “common human species.”
Neanderthals possessed remarkable adaptability and intelligence, crafting intricate tools, producing cave art, mastering fire, and likely wielding sophisticated communication beyond simple grunts. Though their distinct cultures and populations are gone, their genetic legacy echoes through us all.
We are not simply cousins to Neanderthals; they are also our ancestors—a complex and fascinating chapter in the story of human evolution.
