Modern humans and their closest extinct relatives, Neanderthals, may have coexisted for up to three millennia, in what is now France and Northern Spain, a new study reports. This was until the Neanderthals mysteriously disappeared from Earth around 40,000 years ago. Archaeologists from Leiden University and Cambridge University provide important insights into human evolutionary history in the new study published in Scientific Reports.
Modern humans and Neanderthals started coexisting 42,000 years ago
However, it is still not clear when and where these populations may have existed in Europe, according to the researchers. Neanderthals and modern humans coexisted about 42,000 years ago, when modern humans are believed to have appeared in the region. The overlap existed until about 40,000 years ago, when the Neanderthals mysteriously disappeared from Earth, and became extinct.
Neanderthals, the closest extinct human relative, had defining features such as a huge nose, angled cheek bones, sloped forehead, bodies shorter and bulkier than humans, and large brains. The Neanderthal brain was often larger than the human brain, and was proportional to the brawnier bodies of the extinct hominins.
How did the study find the period of coexistence for Neanderthals and modern humans?
The archaeologists analysed a dataset of Neanderthal and modern human artefacts from 17 archaeological sites across France and Northern Spain, and an additional ten Neanderthal specimens from the same region. The samples were dated using new radiocarbon modelling methods for greater accuracy.
In a statement released by Leiden University, the researchers say the chances of discovering and dating the first or last appearance of a species, culture or technology in the archaeological and fossil records are extremely slim. Therefore, the researchers used an important method adapted from biological conservation science, called optimal linear estimation modelling. This is a technique which produces a point estimate of the time of extinction.
For how long did Neanderthals and modern humans coexist?
The researchers used known dated occurrences for the presence of these groups and estimated that Homo sapiens (modern humans) and Homo neanderthalensis may have coexisted in France and northern Spain for between 1,400 and 2,900 years.
According to the researchers, the results suggest that this period of overlap between modern humans and Neanderthals may have been geographically structured. Groups of modern humans may have first appeared and occupied the southern limits of the study region, spatial and chronological data indicates. Meanwhile, Neanderthals continued to occupy the northern extensions, the study says. This geographic pattern is consistent with the hypothesis of Homo sapiens arriving in France along the Mediterranean coast.
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Modern humans and Neanderthals used similar technologies
Researchers have not yet deciphered the nature and frequency of the interactions between Neanderthals and Homo sapiens. However, there is increasing evidence that modern humans and Neanderthals used similar technologies, lending credence to the idea that this period may have involved a form of interaction between these populations.
New excavations and analyses, including sedimentary aDNA (archaeological DNA), could shed new light on the fascinating period, and the circumstances surrounding the mysterious demise of Neanderthals in western Europe.
More about Neanderthals
Neanderthals made and used a diverse set of sophisticated tools, controlled fire, lived in shelters, were skilled hunters of large animals, made and wore clothing, and occasionally made ornamental objects.
The first Neanderthal specimen was discovered in 1856 in Germany. In 1864, geologist William King suggested the name Homo neanderthalensis for the extinct human relative, making it the first fossil hominin species to be named.
The other archaic human groups who walked the Earth during the middle to late Pleistocene Epoch (one million to 11,700 years ago) were Homo floresiensis and Denisovans.
While Neanderthals developed outside Africa and populated Europe and Western Asia from around 400,000 years until 40,000 years ago, Homo sapiens first appeared in Africa approximately 300,000 years ago. Neanderthals mysteriously disappeared from Earth around 40,000 years ago.
Some groups of Homo sapiens migrated from Africa to the Middle East about 70,000 years ago. From Africa, these groups spread to the rest of the world. Therefore, for tens of thousands of years, Homo sapiens and Neanderthals coexisted in large parts of Eurasia.
Genetic information about humans as well as Neanderthals is necessary to know about the relationship between the two species. In the early 2000s, about 92 per cent of the genome had been decoded under the Human Genome Project. Earlier this year, the remaining eight per cent was sequenced.
The 2022 Nobel Prize in Physiology was awarded for research on Neanderthals and Denisovans
Swedish geneticist Svante Pääbo, who won the 2022 Nobel Prize in Physiology or Medicine, did pioneering work in the genetic analysis of Neanderthals and Denisovans, the extinct relatives of human beings. Pääbo was awarded the Nobel Prize “for his discoveries concerning the genome of extinct hominins and human evolution".
Following the migration of Homo sapiens out of Africa around 70,000 years ago, gene transfer occurred from the now extinct hominins to modern humans. The immune system of human beings is able to fight certain infections due to the presence of genes from Neanderthals and Denisovans.
Pääbo achieved a seemingly impossible task of sequencing the Neanderthal genome.
Comparative analyses between Neanderthals and Homo sapiens showed that the most recent common ancestor of the two species roamed Earth around 800,000 years ago.
Through comparative analyses, Pääbo and his team investigated the relationship between Neanderthals and modern-day humans, and found that the DNA sequences were more similar to sequences from contemporary humans originating from Europe or Asia than to contemporary humans originating from Africa. This suggests that Neanderthals and Homo sapiens interbred during their period of coexistence, which lasted thousands of years.
Approximately one to four per cent of the genome of modern-day humans with European or Asian descent has originated from the Neanderthals.
There are several Neanderthal genes which affect humans' immune response to different types of infections.