For the first time, an international group of scholars has been able to take a look at the social organization of a Neanderthal community: 13 individuals who lived in Siberia more than 50,000 years ago, including a father with a teenage daughter and a young boy with an adult relative, perhaps a cousin, aunt or grandmother.
Analysis of their genomes showed that these Neanderthals were part of a small group of close relatives, consisting of 10-20 members, and that communities of this type were connected mainly through female migration.
The study – published on Nature – was led by researchers from the Max Planck Institute for Evolutionary Anthropology, headed by the newly awarded Nobel Prize for Medicine Svante Pääbo. The only Italian author is Sahra Talamo, professor at the University of Bologna and director of the radiocarbon laboratory Bravho (Bologna Radiocarbon Laboratory Devoted to Human Evolution).
The first Neanderthal community
The genetic analyzes carried out in recent years on the remains of Neanderthalians have allowed us to obtain important information on the history of this human population and on their relations with modern humans. Until now, however, we knew very little about the social organization of their communities. To explore this still nebulous aspect of our distant cousins, the scholars therefore turned their attention to southern Siberia: a region that in the past has proved very fruitful for ancient DNA research. In particular, the investigations focused on two caves in the Altai region: Chagyrskaya and Okladnikov. At these two sites, which were briefly inhabited some 54,000 years ago, researchers have successfully recovered and sequenced the DNA of 17 Neanderthal remains – the highest set of such remains ever sequenced for a single study. The results show that the remains belong to 13 Neanderthal individuals: 7 men and 6 women, including 8 adults and 5 children and young adolescents. DNA analysis revealed that in the group of individuals there was also a Neanderthal father and his teenage daughter and a second-degree couple of relatives consisting of a boy and an adult woman, possibly a cousin, aunt or grandmother.
The remains analyzed
In addition, several shared heteroplasmies were found in the mitochondrial DNA of the analyzed remains: a particular type of genetic variant that persists only for a small number of generations. According to the scholars, the presence of heteroplasmies in combination with evidence from related individuals strongly suggests that these Neanderthals lived – and died – around the same time. “It is a truly surprising and exciting result: the fact that these individuals lived at the same time means that they probably came from the same social community,” says Laurits Skov, of the Max Planck Institute for Evolutionary Anthropology and first author of the study. “For the first time, therefore, it was possible to use the tools of genetics to study the social organization of a Neanderthal community.”
Intertwining of communities and female migration
Another surprising finding that emerged from the study is that genetic diversity was extremely low within this Neanderthal community – a figure that suggests it was a group of 10-20 individuals. These are much smaller than those recorded for any ancient or present human community, and more similar to the size of groups of endangered species. However, Neanderthals did not live in completely isolated communities. By comparing the genetic diversity of the Y chromosome (inherited from father to son) with that of mitochondrial DNA (inherited from mothers), it was possible to establish that these Neanderthal communities were mainly connected by female migration. “These surprising results on the evolution of migration must make us reflect on the role of women since the beginning of our fascinating evolutionary history: a woman who has always been gifted with the ability to innovate, find resources, solutions, and” network ” », Comments the University of Bologna professor Sahra Talamo, who performed radiocarbon dating of some of the Neanderthals in the Chagyrskaya cave.
The most eastern Neanderthals
Located at the foot of the Altai Mountains in Siberia, the Chagyrskaya cave has been excavated in the past 14 years by researchers from the Institute of Archeology and Ethnography of the Russian Academy of Sciences. In addition to several hundred thousand stone tools and animal bones, scientists have recovered more than 80 fragments of Neanderthal bones and teeth – one of the largest fossil assemblages of these humans found worldwide. Neanderthals from Chagyrskaya and the nearby Okladnikov cave hunted ibex, horses, bison, and other animals that migrated through the region’s river valleys. The raw materials used to build their stone tools were collected even tens of kilometers away: the presence of these raw materials in both the Chagyrskaya and Okladnikov caves supports the genetic data that indicate how the groups that inhabited these localities were closely linked. “The results we have obtained allow us to draw a concrete picture of what a Neanderthal community could be like,” says Benjamin Peter, of the Max Planck Institute for Evolutionary Anthropology, one of the study coordinators. “Putting all these elements together we have a much more human image of Neanderthals.”
Previous studies
Previous studies on a fossil toe from the famous Denisova cave (located less than 100 kilometers away) had shown that Neanderthals inhabited the Altai Mountains even in much earlier times, around 120,000 years ago. This is the easternmost region in which Neanderthal remains have ever been found. However, the Neanderthals found in the Chagyrskaya and Okladnikov caves are not descendants of these earlier groups. In fact, genetic data show a greater proximity to European Neanderthals. A fact also supported by the archaeological material: the stone tools of the Chagyrskaya cave are in fact more similar to the so-called Mycoco culture, also known in Germany and Eastern Europe.
The protagonists of the study
The study – published on Nature with the title “Genetic insights into the social organization of Neanderthals” – was created by a large international research group led by the Max Planck Institute for Evolutionary Anthropology (Germany), headed by Nobel Prize for Medicine Svante Pääbo. The only Italian in the research group is Sahra Talamo, professor at the “Giacomo Ciamician” Department of Chemistry at the University of Bologna and director of the new radiocarbon laboratory Bravho (Bologna Radiocarbon laboratory devoted to Human Evolution). Also active at the Max Planck Institute for Evolutionary Anthropology, Professor Talamo is Principal Investigator of various projects, including the Erc Resolution project, and the Doing research in Italy Eurhope project. All research projects that lead to highlight the importance of radiocarbon dating to shed light on key periods of European prehistory.