How Much Did Homo sapiens Contribute to the Extinction of the Neanderthals Around 40,000 Years Ago? — Here’s What Scientists Suggest

Neanderthals are an archaic human that is part of the genus Homo, like Homo sapiens. They inhabited Europe and some parts of Asia, even before the modern human species migrated there. They are believed to have physically stronger bodies and a larger brain than us. However, around 40,000 years ago, their species completely disappeared.

It is generally accepted that their extinction was not caused by a single factor but instead a combination of different reasons that made survival more difficult. One of these factors was the arrival of Homo sapiens, or the modern humans. But, how much did our ancestors actually contribute to the demise of their human relatives? Could we possibly be the biggest reason why they are not walking on Earth here with us anymore? Let’s dive deeper into these questions and ideas.

Timing and Arrival of Homo sapiens

Homo sapiens, or the modern human species, is believed to have originated in Africa. They have lived and evolved there for over 200,000 years. But because of various reasons like climate change, they had to move to a different environment to survive. Some records show that over 100,000 years ago, some groups had already tried to cross to other continents, but ultimately they failed, and none of the current living humans came from their lineage.

However, around 70,000 to 50,000 years ago, Homo sapiens were able to successfully arrive in Asia. In regions like the Middle East and the Zagros mountains, they met the Neanderthals. In other words, the fossils archaeologists have discovered suggest that the timeline of existence of these two species on the same continents overlapped, and they may have possibly lived in the same habitats.

These meetings and interactions could have contributed greatly to the eventual extinction of the Neanderthals around 40,000 years ago. However, how exactly did modern humans add to the survival pressure on the Neanderthals, and were they already in a decline before Homo sapiens even arrived there?

Read more: Science Direct

Competitive Advantage, Resource Use, and Social Structure

DNA Analysis Reveals the REAL Reason Neanderthals Went Extinct

Some of the possible theories on just how much modern humans contributed to the demise of the Neanderthal species suggest that we are a significant factor among many others. First, when Homo sapiens arrived in the same habitats as the Neanderthals, we may have had a larger population size.

A greater number means we are more resilient to changes in our environments and to diseases. It also meant being less prone to inbreeding and having a larger genetic pool. On the other hand, Neanderthal groups may have survived in a smaller and more isolated population. This scenario would have given Homo sapiens a competitive advantage.

Another reason could be that we have more advanced social structures and networks. If Homo sapiens, who may have already had a higher number, were also more interconnected and had better cooperation, our species could have outcompeted Neanderthals in resource acquisition and territorial expansion. These traits and characteristics would have facilitated the exchange of information and resources across a greater distance.

The modern human species’ advanced weapons and technology could also have played a role. We may have had a wider range of sophisticated and specialized tools, like a projectile spear and better-suited clothing that would have protected us from the cold. These inventions could have given them a competitive advantage over Neanderthals in hunting and adapting to the environment.

Interbreeding, Genetic Dilution, and Disease

Another fascinating theory is that Homo sapiens contributed to the extinction of Neanderthals by interbreeding and possibly absorbing some of their groups. Genetic evidence shows that modern humans today, who originated outside of Africa, have about 1 to 4% Neanderthal DNA in their genome.

This information led to a recent hypothesis that suggests Homo sapiens, instead of outright displacing and eradicating the Neanderthals, may have gradually absorbed them genetically. This would have reduced their already small distinct population even more.

Another theory is that when these two different species, which have been living in separate and different environments for hundreds of thousands of years, met, they may have passed diseases to one another. Homo sapiens could have brought pathogens that Neanderthals are not immune to.

Take these theories together, the wave of mixing and interbreeding, combined with the possibility of local Neanderthal populations being wiped out by diseases brought by Homo sapiens, paints a picture of how our species could have added indirect pressures to the survival of these other humans, aside from the more direct resource and territorial competitions.

Read more: Stanford

Climate Change, Small Populations and Multiple Causes

What Caused The Extinction Of The Neanderthals? | The Neanderthal in Us

While Homo sapiens are believed to have contributed significantly to the extinction of Neanderthals, it is possible that they were already a human species in decline before our ancestors even arrived on the same continents. One other factor could be climate change, causing their natural habitats to be less abundant and harsher.

There were recorded shifts in the environment in Europe and Asia, where major cold spikes could have stressed all the humans living in the area. It may have led to less vegetation, causing some animals to migrate to other environments or perish, ultimately resulting in fewer resources for Neanderthals to survive in. Combine this with the arrival of Homo sapiens to compete for the same food sources and territories, and it could have created a perfect storm that led to their extinction.

However, even without that competition from the modern human species, Neanderthals are believed to have already been living in small and isolated population groups. They may have been fragmented because of climate change and environmental challenges, making them prone to inbreeding and genetic bottlenecks, which would have resulted in being more vulnerable to being wiped out by diseases and fluctuations in their habitats.

Therefore, scientists often do not attribute the extinction of the Neanderthals to just one reason, like the arrival of Homo sapiens. Instead, it is more acceptable based on genetic and fossil discoveries that they faced a multitude of factors that they were not able to adapt to. The competition with the modern human species is just one of many, but it is still a significant contributor.

Author's Final Thoughts

The story of how Neanderthals survived and how much Homo sapiens contributed to their extinction is complex. Homo sapiens likely played a major role, but so did climate change and other environmental challenges. Ultimately, the disappearance of Neanderthals should remind us that the evolution and extinction of a species is often a result of many interacting forces rather than a single primary cause.

Even today, as we discover more evidence and conduct studies that further the information we have, these stories would most likely continue to change and evolve, highlighting the dynamic nature of scientific understanding and the mystery of our shared evolutionary past.

Read next: Why Did Homo erectus, After Surviving for Nearly 2 Million Years, Finally Go Extinct Around 110,000 Years Ago? — Here’s What Experts Suggest

References & Further Reading

Villa, P., & Roebroeks, W. (2014). Neandertal Demise: An Archaeological Analysis of the Modern Human Superiority Complex. PLOS ONE. https://doi.org/10.1371/journal.pone.0096424

Higham, T., et al. (2014). The timing and spatiotemporal patterning of Neanderthal disappearance. Nature. https://doi.org/10.1038/nature13621

Staubwasser, M., et al. (2018). Impact of climate change on the transition of Neanderthals to modern humans in Europe. PNAS. https://doi.org/10.1073/pnas.1808647115

Timmermann, A. (2020). Quantifying the potential causes of Neanderthal extinction: Abrupt climate change versus competition and interbreeding. Quaternary Science Reviews. https://doi.org/10.1016/j.quascirev.2020.106331

Banks, W. E., et al. (2008). Neanderthal extinction by competitive exclusion. PLOS ONE. https://doi.org/10.1371/journal.pone.0003972