A new theory put forward by Dr Anna Degioanni from Aix Marseille Université suggests that falling fertility rates may not be unique to the 21st Centurty.
It is often assumed that our prehistoric relatives, the Neanderthals became extinct 40,00 years ago as a result of some catastrophic environmental disaster or disease. In a new paper, published in the Plos One Journal, Degioanni suggests that their disappearance may have something more to do with a more recent phenomenon (or so we thought), that of falling fertility rates. Specifically, Degioanni identifies the possibility that young females became infertile, ultimately leading to the extinction of the Neanderthals.
According to a recent article published in The Independent newspaper, Dr Degioanni’s model suggests extinction would have been possible within 10,000 years if there was a 2.7 per cent decline in fertility rates of Neanderthal women under the age of 20. If they fell by eight per cent extinction occurred within 4,000 years.
She said theories that suggest Neanderthals died out because of epidemics or conflicts are unlikely to be correct because they would have caused the population – estimated to be made of 70,000 individuals – to be wiped out considerably faster.
“This study does not attempt to explain ‘why’ the Neanderthals disappeared – but to identify ‘how’ it may have taken place,” she said. “First-time pregnancies, especially in young females (less than 20 years old), are on average more at risk than second and other pregnancies… a slight decrease in food may explain a reduction in fertility, especially among first-time mothers.”
Current research suggest Neanderthals went extinct over a period of 4,000 to 10,000 years. Their demise was not believed to be brutal and occurred over a long period of time.
Neanderthals arrived in Europe 250,000 years ago. This is the first study to use empirical data to suggest that relatively minor demographic changes, such as a reduction in fertility or an increase in infant mortality, might have led to Neanderthal extinction.
“Our results open the way to non-catasrophic events as plausible explanations for Neanderthal extinction,” researchers said.