The extinction of Neanderthals

200,000 years ago, at least seven species of humans existed.

Now there is only one, Homo sapiens – our species. Neanderthals were our closest human species and similar to Homo sapiens in many ways, but why did Homo sapiens survive and Neanderthals become extinct? The reasons for the extinction remain controversial but scientists are much closer today than ever before in answering this question. In the past, scientists believed that Homo sapiens were superior to Neanderthals and outcompeted them, but now new evidence suggests that it was instead due to a combination of environmental and biological factors.

Humans evolved in East Africa from a genus of apes. These early humans settled all over the world, and as the climates and conditions differed from place to place, they acquired different traits and behaviours and thus became different species. Neanderthals lived in Europe and Asia and Homo sapiens lived in Africa. Only recently climate had been considered a cause of the Neanderthal extinction. This is because Neanderthals were adapted to the cold environment, for example they had a relatively short, stocky body so they could generate and retain more body heat, so the idea that the climate could cause any other issues for them was disregarded. Around 40,000 years ago, when Neanderthals became extinct, Europe was in a period of rapid climate change. Neanderthals struggled to adapt to the changing landscape caused by the colder, drier climate as the forests they were used to, where they could ambush and hunt deer or larger animals, started disappearing. Whilst they were intelligent enough to adapt by making different tools, their body shape could not adapt fast enough to suit the new environment. Neanderthals short, stocky body needed much more food than Homo sapiens, so with their habitat under threat and food sources disappearing this would have been very difficult to maintain. This consequently meant the Neanderthal population was reduced, evident by the lack of genetic diversity, making the population very susceptible to diseases, with limited mating choices meaning the small populations failed to grow.

The extreme climate changes alone were unlikely to have caused the Neanderthals extinction as they had survived cold phases before, some even more extreme than what was occurring at the time, but instead the arrival of Homo sapiens from Africa 45,000 years ago may have been the final blow to the species. The forests had become open plains similar to African savannahs that Homo sapiens were used to, meaning they had an advantage. However, the idea that Homo Sapiens were superior and actively replaced and outcompeted Neanderthals is unlikely as there is increasing evidence to suggest Neanderthals were more intelligent and resourceful than previously thought. Neanderthal brains were often larger than Homo sapiens brains, allowing them to have a sophisticated culture. They built shelters, made clothing and created advanced tools; they were the first humans to makes tools out of bone. It is very possible that both Homo sapiens and Neanderthals had sophisticated weapons such as spears which had many advantages in an open area as they could be thrown, making it possible to hunt a greater

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variety of species. New evidence also suggests Neanderthals hunted in groups similar to Homo sapiens meaning there were few differences in hunting techniques between Neanderthals and Homo sapiens, as was previously thought. The competition for already limited resources combined with the already small Neanderthal population may have been enough for them to go extinct.

Another argument against Homo sapiens being superior to Neanderthals is that Homo sapiens first migrated out of Africa 100,000 years ago to the Middle East, then to Australia 60,000 years ago, but why did it take them another 15,000 years to migrate to Europe when it is so geographically close to Africa? Professor Clive Finlayson believed the answer to be that the Neanderthals in Europe kept Homo Sapiens out. This means that Homo sapiens were only able to migrate to Europe because the changing climate weakening Neanderthals allowed them to.

Finally, there was a 5,000 year period when both Neanderthals and Homo sapiens lived in Eurasia. Another theory suggests Neanderthals did not go extinct but interbred with Homo sapiens and were absorbed in the larger Homo sapien population. This is strengthened by the fact most people of European or Asian decent have 1-2% Neanderthal genes in their DNA.

Considering all the evidence, the extinction of Neanderthals was mostly likely a combination of all three factors and happened over a period of 5,000 years. Climate change reduced the Neanderthal population size and forced them into core areas which left Europe open to Homo sapiens. This led to further food shortages and with Neanderthal populations struggling, some Neanderthals joined Homo sapien groups whereas others died out.

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