Neanderthal extinction was neither caused by Climate Change, nor the confrontation with our ancestors, the Homo sapiens. A new study explains what happened to the Neanderthals? Why they suddenly disappeared.
Scientists at the IBS Center for Climatic Physics have discovered that, contrary to popular belief, the Neanderthal extinction was not caused by abrupt climatic changes or by crossbreeding with Homo sapiens. According to new simulations of supercomputer models, the reason for the rapid disappearance of Neanderthals from 43 to 38 thousand years ago was competition for resources with our ancestors Homo sapiens.
Neanderthals lived in Eurasia for at least 300,000 years. 43 to 38 thousand years ago they quickly disappeared from the face of the earth, leaving only faint genetic traces in today’s Homo sapiens populations. Humans today carry traces of these Neanderthal genes in our cells.
The extinction of the Neanderthals coincided with a period of very radical changes in the climate, and also with the emergence of Homo sapiens in Europe. However, determining which of these factors was the dominant cause remains one of the greatest challenges in evolutionary anthropology.
In order to quantify which processes played an important role in the collapse of Neanderthal populations, it is necessary to use mathematical models that can realistically simulate the migration of Neanderthals and Homo sapiens, their interactions, competition, and miscegenation in a changing climate environment. Such models did not previously exist.
THE MAP SHOWING THE ARRIVAL OF THE HOMO SAPIENS
In a new article published in the Quaternary Science Review, Axel Timmermann, Director of the IBS Climate Physics Center at Pusan National University, presents the first realistic simulation of a computer model of the Neanderthal extinctions across Eurasia. Is this:
Consisting of several thousand lines of computer code and running on IBS ‘Aleph supercomputer, the model solves a series of mathematical equations that describe how Neanderthals and Homo sapiens moved in a glacial landscape that varies with time and under changing patterns of temperature, rain, and vegetation.
In the model, both groups of hominids compete for the same food resources and sometimes interbreed. The key model parameters are derived from realistic simulations of computer-based climate models and genetic and demographic data.
“This is the first time that we can quantify the drivers of the Neanderthal extinction,” says Timmermann, lead author of the study. “In the computer model I can activate and deactivate different processes, such as abrupt climate change, miscegenation, or competition,” he explains. By comparing the results with existing paleoanthropological, genetic, and archaeological data, Timmermann shows that realistic extinction in the computer model is only possible if Homo sapiens have significant advantages over Neanderthals in exploiting existing food resources.
Although the model does not specify the details, the possible reasons for the superiority of Homo sapiens could have been associated with better hunting techniques, greater resistance to pathogens, or a higher fertility level. That is, Homo sapiens were more adept at looking for food. It reproduced more easily, and it resisted viruses and other pathogens better. And that was the superiority that gave them an advantage.
What exactly caused the Neanderthal’s rapid disappearance has remained elusive for a long time. This new approach to computer modeling identifies competitive exclusion as the probable reason for the Neanderthal extinction. “Neanderthals lived in Eurasia for the past 300,000 years and experienced and adapted to abrupt climatic changes, which were even more dramatic than those that occurred during the time of the Neanderthals’ disappearance. It is not a coincidence that Neanderthals disappeared just as Homo sapiens began to spread throughout Europe, “says Timmermann. And he adds: “New computer model simulations clearly show that this event was the first major extinction caused by our own species.”
A research team from the IBS Climate Physics Center is improving the computer model to also include megafauna and implement more realistic climate forcings. “This is a new field of research in which climate scientists can interact with mathematicians, geneticists, archaeologists, and anthropologists,” said Axel.