Did Homo sapiens drive Neanderthals to extinction?
This week we delved into the world of paleoanthropology, the study of human evolution. When our species, Homo sapiens, first appeared, we shared the planet with several other human-like species. Perhaps the most famous of these were the Neanderthals.
The Neanderthals, roamed Europe and Asia for 400,000 years, then they disappeared. The cause of their extinction is hotly debated amongst experts. One of the reasons may have been us, Homo sapiens. At the time that Neanderthals went extinct, our ancestors moved out of Africa and began populating the rest of the world. This leads us to ask: did our ancestors simply fill the territories Neanderthals had left behind, or did their movement North drive the Neanderthals downfall? We asked 16 experts whether Homo sapiens drove Neanderthals to extinction, the consensus was 'Uncertain' with a score of 50%. Here is what we found…
Before you read on, consider becoming a paid subscriber to support us and our scientists communicate the facts.
Did Homo sapiens drive Neanderthals to extinction?
Is there any evidence that Homo sapiens and Neanderthals fought each other?
Due to the classic portrayal of ‘cave man’ being violent in nature, supported by fossils showing that both Homo sapiens and Neanderthals frequently suffered traumatic injuries, we might infer that our ancestors brutally killed all the Neanderthals. There was an overlap of at least 100,000 years between the two species, but archaeological evidence suggests that, in most areas, modern humans only arrived after Neanderthals had died out.
Genetic evidence, on the other hand, shows that some gene exchange occurred between the two species, meaning that they bred together. As a result of this, about 2% of the DNA of non-African descendants is Neanderthal. Expert Professor Pettitt from Durham University thinks this close contact “was probably at the edges of their ranges, i.e. in western and central Asia, and not in their European core.”. He adds that “while contact obviously did occur from time to time, and that such contact could have been violent, if this did occur it was exceptional, and certainly nowhere near enough to cause, or probably even contribute in a minor way, to Neanderthal extinction.”
Professor Hunt believes that more data is required to confidently answer this question. He believes “we have to concentrate effort on sites where it looks as if there was no gap between Neanderthals and H. sapiens. It then requires very high-resolution dating to demonstrate that the gap between one and the other was very short, and a careful exploration of the evidence about what Neanderthals and H. sapiens were doing on the site, how they lived, the ecology and climate of the time and so forth.” Such investigation is currently taking place at Shanidar Cave in Iraq.
Is there any evidence that Homo sapiens competed with Neanderthals for resources and territories?
Neanderthals shared a lot of similarities with our ancestors. Like the ancient Homo sapiens, they made fires, hunted large animals and even cared for the injured. These similarities suggest that the two species would have thrived in similar territories. Dr Sorensen from Leiden University says the “inflow of peoples from Africa would have increased competition for food resources”. This theory assumes that Homo sapiens certain advantages over Neanderthals, such as superior intelligence, adaptability or strength. Although the exact nature of this advantage is not clear, archaeological evidence suggests that our ancestors’ population increased tenfold as they replaced Neanderthals in Europe.
Could the Neanderthals have been wiped out by climate change?
“Neanderthals went extinct at a time when a lot of other ecological things were happening.There were extinctions of a number of large mammals during this general time including the cave bear and the cave hyaena.” says Dr Stewart from Bournemouth University. This means that other factors, such as climate, may have played a role in the disappearance of Neanderthals. Professor Shea notes that the timing of Neanderthal extinction coincides with “the Heinrich H5 Event, a several thousand-years long shift from already very cold conditions to even colder conditions … the H5 event probably wiped out most of them, and swiftly, for such events happen fast. The survivors might have lived on in pockets along the Mediterranean, where their numbers dwindled.”
Are there any other explanations for the extinction of Neanderthals?
A recent publication asked 216 paleoanthropologists what they thought drove the extinction of Neanderthals. The most popular reasons were demographic factors. This means statistical factors that influence populations, such as initial population size, inbreeding and stochasticity. The Neanderthal population was likely very small, making it vulnerable to extinction as a result of even small environment changes.
Interestingly, a 2017 publication used a computer model to show that Neanderthal extinction could occur without the need for competition from Homo sapiens or climate change. Another model made in 2019 could simulate the extinction of Neanderthals simply through natural shifts in the population birth and death rates. When the migration of Homo sapiens was included in this model, our ancestors only needed to migrate into territories in such a way that the already small Neanderthal population became fragmented - no competition was needed.
In conclusion, there is no clear consensus on what caused the extinction of Neanderthals, and whether our ancestors are to blame. Most researchers in the field agree with Professor Akey that “a number of reasons likely explain why the Neanderthal lineage ended ~30,000 years ago.” Dr Kolodny adds that, “the majority of living humans carry in their genes some 1%-2% of DNA sequence that originates in Neanderthals, so in some sense they never went extinct at all.
May the facts be with you,
Is red wine good for you?
Metafact Review on Alcohol
Exclusive reviews for our fact-loving subscribers & members.
Each month we investigate a topic voted by the community by asking the world's top experts to review the evidence. Reviews are what you need to know. You can read all the reviews online here.
Most of us drink alcohol, but for different reasons. Many people drink for enjoyment and socializing with friends. Others drink to relax and unwind from a stressful day. Over the years, many claims get thrown around like "Red wine is good for you" or "Alcohol causes cancer". Are these true? What is the evidence behind them? And what level of alcohol consumption is safe?
This month we investigated alcohol with 30 independent experts from across the globe. Here's what we found...