It has been around 40.000 years since the Neanderthals disappeared. It has also been about 40.000 years since modern humans started expanding in other territories, besides Africa, into Europe and the Middle East.
These dates should be a coincidence, right? They match up so well. Well, there’s a new study that shows that the Neanderthals became extinct, but not because the Homo sapiens made their appearance.
A team from the Eindhoven University of Technology, from the Netherlands, made computer models to simulate the effects of different factors on the Neanderthal populations, which has different sizes, from 50 to 500 to 5000. They did it based on data gathered from studies of modern hunter-gatherer populations from all around the world.
When Neanderthals Disappeared, It Was Not Because of Modern Humans
These factors modeled had to do with fluctuations in birth, inbreeding and death rates changes, and the ‘Allee effects,’ which is a phenomenon that was first identified back in the 1950s. It suggested that, in a shrinking population, the average health and fitness of the individuals actually tends to decline in time.
The team of researchers found that the Allee effects could be the reason behind the extinction of the population number being less than 1000 people. Inbreeding, together with the Allee effects, could be the reason for the entire species of Neanderthal to decline in the period of 10,000-years, without modern humans to actually be part of this.
So the Neanderthals did not disappear because we, modern humans, made our appearance, but because they had a bit of bad demographic luck. The entire thing is made out of two mechanisms. The conflict of the incoming humans might have been a cause to the acceleration of the Allee effects in the population; another reason might have been the reduction in size.