Has infertility killed the Neanderthals? The mysterious disappearance of the old species can be explained by a 2.7% decrease in fertility of women
- There is currently no accepted theory as to why the Neanderthals are extinct
- Focus primarily on catastrophic events such as illness, warfare or climate change
- New theory suggests that it may be a consequence of a declining female fertility
- Found a decrease of 2.7 percent, the species would be destroyed in 10,000 years
- But a decrease of five and eight percent accelerated this to 6,000 and 4,000 years respectively
Neanderthals may have died out because the women of the old hominids slowly but surely became infertile, researchers suggest.
Scientists need to agree on a single reason to explain why they disappeared.
Current theories are focused on catastrophic events such as illness, warfare or climate change, but there is little evidence for this.
A researcher from France investigated the possibility that it was due instead to a decrease in fertility and investigated how much influence it would have on the long-term survival of the whole species.
Mathematical models showed that a decrease of fertility by only 2.7 percent would destroy the species in 10,000 years.
Scroll down for video
Scientists need to agree on a single reason to explain why they disappeared. Current theories focus on catastrophic events such as illness, warfare or climate change, but there is little evidence for this (file photo)
The study used computer models to predict how quickly extinction came and was conducted by a team led by Anna Degioanni from the University of Aix-Marseille.
They looked at what should change in Neanderthal groups to see the population fall below 5,000 – which the study considers functionally extinct.
It included female fertility, adult mortality and the chances of survival of babies.
They looked at what subtle changes would be needed to make them die out in 4,000 years, 6,000 years and 10,000 years.
These time frames are considered by many scientists to be the most likely periods that Neanderthals died out.
Researchers focused primarily on female fertility and found that a 2.7 percent decrease would be enough to cause the species to die out in ten millennia.
But a decrease of five and eight percent ensured that their downfall had risen to 6,000 and 4,000 years respectively.
The researchers write in the paper: & # 39; We show that in the long term a slight change in the fertility rate of younger women may have had a dramatic impact on the growth rate of the metapopulation of the Neanderthals and thus on the chances of survival on the long-term. consistent with the observed extinction of Neanderthals within a 10,000, 6,000 or 4,000 year period & # 39;
|Years to extinction||Female fertility||Infant mortality|
|4000||-8%||N / A|
Mathematical models revealed a decrease in fertility of just 2.7 percent should the Neanderthals be destroyed in 10,000 years. But a decrease of five and eight percent accelerated this to 6,000 and 4,000 years respectively
A reason behind the decline is not mentioned by the researchers, but they suggest for the time being that this would probably have been caused by food scarcity.
The authors add: & # 39; Because the amount of stored body fat influences fertility in women, a decrease in resources (caused by climate deterioration or competition with sapiens) can affect fertility, especially in young women who were first gave birth. & # 39;
The study was published in the journal PLOS ONE and also the chance of survival of babies & # 39; s should be reduced by only 0.4 percent to send them extinct in 10,000 years.
A marginal increase to one percent sees this rise enormously to just 6,000 years, showing how important surviving offspring were to Neanderthals.
Just like people, they reproduced slowly and invested heavily in their children. other mammals have large nests to compensate for low chances of survival, but primates, and in particular hominins, invest a large amount of resources in a few youngsters.
Another finding in the study was that if adult survival had decreased by ten percent, this would have a catastrophic impact on the species as a whole, causing it to die out almost immediately.
Researchers suggest that Homo sapiens disease or warfare is a likely cause of this type of rapid decline.
WHO WERE THE NEANDERTHALS?
The Neanderthals were a close human ancestor who mysteriously died out around 50,000 years ago.
The species lived in Africa with early humans for hundreds of millennia before moving to Europe about 500,000 years ago.
Later they were accompanied by people who took the same journey in the last 100,000 years.
The Neanderthals were a cousin of humans, but not a direct ancestor – the two species that were split from a common ancestor – who died around 50,000 years ago. Depicted is a Neanderthal museum exhibition
These were the original & # 39; cavemen & # 39 ;, historically dull and brutal compared to modern people.
In recent years, and especially in the last decade, it has become increasingly clear that we have sold Neanderthals briefly.
A growing number of evidence points to a more refined and multilingual type of & # 39; caveman & # 39; than anyone had ever thought possible.
It now seems likely that Neanderthals buried their dead with the concept of an afterlife in mind.
Moreover, their eating habits and behavior were surprisingly flexible.
They used body art such as pigments and beads, and they were the very first artists, with Neanderthal cave art (and symbolism) in Spain apparently dating back to the earliest modern human art in around 20,000 years.
. (TagsToTranslate) Dailymail (t) sciencetech (t) france (t) climate change – & – global-warming