Transatlantic exploration took place centuries before the crossing of Columbus. Physical evidence for early European presence in the Americas can be found in Newfoundland, Canada. However, it has thus far not been possible to determine when this activity took place.
In this study researcher provided evidence that the Vikings were present in Newfoundland in ad 1021. The researchers overcome the imprecision of previous age estimates by making use of the cosmic-ray-induced upsurge in atmospheric radiocarbon concentrations in ad 993 .
The new date lays down a marker for European cognisance of the Americas, and represents the first known point at which humans encircled the globe. It also provides a definitive tie point for future research into the initial consequences of transatlantic activity, such as the transference of knowledge, and the potential exchange of genetic information, biota and pathologies.
Nature Video
Vikings were living in North America exactly a thousand years ago
A multidisciplinary research team led by the Archaeometry research group of the University of Tübingen and the GEA research group of the University of Granada made a surprising discovery in the megalithic necropolis of Panoría (Granada, Spain): twice as many women as men were buried, a bias that is even more pronounced among the juvenile population, where the ratio is 10 females for every male.
The necropolis of Panoría is located at the easternmost end of Sierra Harana, in the town of Darro (Granada). It consists of at least 19 graves, 9 of which have been excavated between 2015 and 2019. They are collective burials from which more than 55,000 human skeletal remains were recovered. The dating of these remains shows that the first burials took place 5600 years ago with a discontinuous funerary use until 4100 years ago.
In a recent study published in the prestigious journal Scientific Reports, the use of new bioarchaeological methods has allowed the identification of chromosomal sex from the study of DNA and the analysis of a protein known as Amelogenin present in the tooth enamel. In this way, it has been possible, for the first time, to obtain a precise demographic profile of the biological sex of the people who were buried in these megalithic monuments. Surprisingly, the result is a clear bias in favour of female burials, twice that of male burials, a bias that is even more pronounced among juvenile individuals with a ratio of 10 females for every male individual. This ratio is far from the usual composition of human populations, which is approximately one to one. Only in exceptional circumstances, e.g. conflicts, wars or intense migration processes, does this ratio break down in favour of one of the sexes.
What circumstances could have led to such a pronounced bias in the population buried at Panoría? The bias in favour of female burials appears in all the analysed graves, in all age groups and throughout the time of use of the necropolis. This allows us to confirm that this was a very persistent and determining social decision over time affecting the different social groups buried within the graves. Therefore, extraordinary or unpredictable events can been ruled out as the cause of the bias found in Panoría.
If sex bias was a social decision, but what are the reasons for this over-representation of women in funerary rituals? Considering that biological kinship relations are the main criterion to be buried in the different structures, the over-representation of female individuals could indicate funerary practices based primarily on matrilineal descent. This means that family relationships and social belonging are established through the maternal line. This would explain the bias in favour of women and the absence of young male individuals who could have joined other kin groups, a common practice known in anthropology as male exogamy. In any case, the over-representation of women would indicate a female-centred social structure, in which gender would have influenced funerary rituals and cultural traditions.
Credit: Copyright: LI Wenying, Xinjiang Cultural Relics and Archaeology Institute
Food fermentation is the oldest production practice using microorganisms in human history. Milk fermentation, for example, can be traced back to 6000–4000 BC in India, and Mediterranean populations produced and consumed cheese as early as 7000 before present (BP).
Despite the long history of human consumption of fermented products, though, little has been known about the history of the use of fermentative microorganisms and the history of related cultural transmission. In particular, the evolutionary trajectories, especially functional adaptation, of these fermented microorganisms through long-term interactions with humans has been unclear.
Recently, a group of Chinese scientists has added to our knowledge of the dispersion of early dairy fermentation practices, however, by completing the world’s first metagenomic study of Bronze Age kefir cheese unearthed from Xiaohe cemetery—the most ancient dairy remains known to date. Molecular evidence obtained from ancient fermented dairy residues serves as a powerful tool for understanding past human-fermentative microbial interactions.
In this study, the scientists extracted high-quality genomes of Lactobacillus kefiranofaciens (L. kefiranofaciens)from three ancient cheese samples unearthed in Xiaohe cemetery in Xinjiang, dating back to about 3,500 years ago. The group’s findings were published online in Cell on Sept. 25, in an article entitled “Bronze Age cheese reveals human-Lactobacillus interactions over evolutionary history.” It was featured as a Cell Highlighted Paper.
“We has been working on this project for over 11 years,” said FU Qiaomei, the last corresponding author and director of the Molecular Paleontology Laboratory at the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences. The key is she designed probes to enrich Lactobacillus DNA, which increases the target DNA from <1% to 64-80% and enables the reconstruction of the whole genome of Lactobacillus.
“This is an unprecedented study, allowing us to observe how a bacterium evolved over the past 3,000 years. Moreover, by examining dairy products, we’ve gained a clearer picture of ancient human life and their interactions with the world,” says FU. “This is just the beginning, and with this technology, we hope to explore other previously unknown artifacts.”
History of the use and spread of kefir yogurt among ancient Xinjiang populations
The cheese sample excavated from Xiaohe Cemetery in Xinjiang is the earliest cheese product ever found. It was previously identified through paleoproteomics as kefir cheese—a fermented milk product made using kefir grains, which contain fermentative microbes.
By reconstructing the fermentation microbial community, the study confirms that the cheese was made using lactic acid bacteria and yeasts. The researchers also discovered that the milk used to make the cheese came from a clade of goats widely distributed in Eurasia during the post-Neolithic period, distinct from contemporary domesticated goats from inland East Asia.
This finding suggests that ancient peoples from the Tarim Basim probably learned kefir production techniques from Eurasian steppe populations.
The spread of dairy fermentation technology largely accompanied human migration and interaction, a process that drove the evolution of lactic acid bacteria. However, this study also reveals a new route of spread of L.kefiranofaciens by analyzing the phylogenetic relationships of ancient L. kefiranofaciens in Xinjiang.
The researchers found that the L.kefiranofaciens used in fermentation comprised two clades. The first mainly consisted of strains from Europe (e.g., the area occupied by modern Germany) and coastal areas and islands in Asia (e.g., the areas occupied by modern Guangdong, Taiwan Island, Japan, and Singapore). This distribution conformed to the dispersal route from the Caucasus to Europe on the one hand and to the coastal areas of Asia and Southeast Asia, on the other hand. The other clade mainly consisted of strains distributed in inland East Asia (including Tibet).
The reconstructed ancient strains are located at the base of the clade, suggesting an additional route of diffusion of kefir production technology from Xinjiang to inland East Asia through techno-cultural exchange.
The divergence of the two clades of L. kefiranofaciens is likely the result of the spread of their common ancestor initially domesticated in different populations, representing the migration and interactions that occurred during the use and domestication of fermentative microorganisms by different ancient populations.
“It is exciting to see how much information can be retrieved from these cheeses,” said YANG Yimin, a professor at the University of Chinese Academy of Sciences. “Organic residues open a window into past human behaviors and culture that were lost in history and records.”
Domestication and evolution of Lactobacillus by the Xiaohe population
This study also found that utilization and domestication by humans played an important role in the evolution of L.kefiranofaciens. Comparative analysis of the genomes of L.kefiranofaciens from the Bronze Age and modern times allows us to characterize the adaptive evolution of Lactobacilluskefiranofaciens over the past few thousands of years.
Extensive horizontal gene transfer is one of the main mechanisms of adaptive evolution in lactic acid bacteria. By comparing the functional profiles of ancient and modern L.kefiranofaciens, the study found three main trajectories of L.kefiranofaciens evolution: 1) adaptation to environmental stress, with the emergence of drug-resistance-related genes in modern strains; 2) enhancement of bacterial genome defense mechanisms, with modern L.kefiranofaciens showing gene clusters such as the R-M system and the associated toxin-antitoxin system, which can counteract the introduction of exogenous DNA and thus reduce related fitness costs; and 3) adaptations related to the human intestinal environment; for example, modern strains gained gene clusters that potentially interact with the host gut, likely due to their long-term interactions with humans.
This study also found that long-term human use and domestication of L.kefiranofaciens likely also influenced its evolution. Compared to Bronze Age L.kefiranofaciens, modern strains from Tibet show two horizontally transferred gene clusters associated with alleviation of the intestinal inflammatory response. This not only contributes to the survival of L.kefiranofaciens in the human gut but also promotes intestinal function.
Considering ancient populations could easily spread kefir production technology through kefir grains, the presence of these gene clusters is likely related to the preference among populations at the time for kefir grains carrying different clades of L.kefiranofaciens.
“Human-microbial interaction is always fascinating,” said LIU Yichen, one of the first authors and an associate professor at the IVPP Molecular Paleontology Laboratory. “Fermentative microbes played such an important role in the daily life of these ancient humans, and they propagated these microbes for thousands of years without knowing the existence of them for most of the time.”
By using ancient DNA information about fermentative microorganisms closely related to past human activities and culture, this study offers a novel framework for using ancient DNA to examine the cultural interactions of past humans.
The research was supported by the National Natural Science Foundation of China, the Chinese Academy of Sciences, the Peak Biomedical Fund, and the Fundamental Research Operating Expense Fund of the Central Universities.
Multi-disciplinary archaeological survey at the site of Oued Beht, Morocco, reveals a previously unknown 3400–2900 BC farming society.
This is the earliest and largest agricultural complex yet found in Africa beyond the Nile.
It shares similar features with contemporaneous sites in Iberia.
This suggests the Maghreb was instrumental to the shaping of the western Mediterranean during the fourth and third millennia BC.
Archaeological fieldwork in Morocco has discovered the earliest, previously unknown farming society from a poorly understood period of north-west African prehistory.
This study, published today in Antiquity, reveals for the first time the importance of the Maghreb (north-west Africa) in the emergence of complex societies in the wider Mediterranean.
With a Mediterranean environment, a border with the Sahara desert and the shortest maritime crossing between Africa and Europe, the Maghreb is perfectly located as a hub for major cultural developments and intercontinental connections in the past.
Whilst the region’s importance during the Palaeolithic, Iron Age and Islamic periods is well known, there is a significant gap in knowledge of the archaeology of the Maghreb between c. 4000 and 1000 BC, a period of dynamic change across much of the Mediterranean.
To tackle this, Youssef Bokbot (INSAP), Cyprian Broodbank (Cambridge University), and Giulio Lucarini (CNR-ISPC and ISMEO) have carried out collaborative, multidisciplinary archaeological fieldwork at Oued Beht, Morocco.
Prof Broodbank states: "For over thirty years I have been convinced that Mediterranean archaeology has been missing something fundamental in later prehistoric north Africa. Now, at last, we know that was right, and we can begin to think in new ways that acknowledge the dynamic contribution of Africans to the emergence and interactions of early Mediterranean societies"
As the authors state: "For more than a century the last great unknown of later Mediterranean prehistory has been the role played by the societies of Mediterranean’s southern, Africa shores west of Egypt. Our discoveries prove that this gap has been due not to any lack of major prehistoric activity, but to the relative lack of investigation, and publishing. Oued Beht now affirms the central role of the Maghreb in the emergence of both Mediterranean and wider African societies."
These results reveal that the site was the largest agricultural complex from this period in Africa outside of the Nile region. All of the evidence points to the presence of a large-scale farming settlement—similar in size to Early Bronze Age Troy.
The team recovered unprecedented domesticated plant and animal remains, pottery and lithics, all dating to the Final Neolithic period. Excavation also revealed extensive evidence for deep storage pits.
Importantly, contemporaneous sites with similar pits have been found on the other side of the Strait of Gibraltar in Iberia, where finds of ivory and ostrich egg have long pointed to African connections. This suggests that the Maghreb was instrumental in wider western Mediterranean developments during the fourth millennium BC.
Oued Beht and the north-west Maghreb were clearly integral parts of the wider Mediterranean region. As such, these discoveries significantly change our understanding of the later prehistory of the Mediterranean and Africa.
As the authors of the Antiquity article state: “It is crucial to consider Oued Beht within a wider co-evolving and connective framework embracing peoples both sides of the Mediterranean-Atlantic gateway during the later fourth and third millennia BC—and, for all the likelihood of movement in both directions, to recognise it as a distinctively African-based community that contributed substantially to the shaping of that social world.”
As anyone who’s spent time in the saddle knows, riding a horse can be hard on your body. But can it change the way your skeleton looks?
The answer, according to archaeologists from the University of Colorado Boulder: It’s complicated. In a new study, the team drew on a wide range of evidence—from medical studies of modern equestrians to records of human remains across thousands of years.
The researchers concluded that horseback riding can, in fact, leave a mark on human skeletons, such as by subtly altering the shape of the hip joint. But those sorts of changes on their own can’t definitively reveal whether people have ridden horses during their lives. Many other activities, even sitting for long periods of time, can also transform human bones.
“In archaeology, there are vanishingly few instances in which we can tie a particular activity unequivocally to skeletal changes,” said Lauren Hosek, lead author of the study and an assistant professor in the Department of Anthropology at CU Boulder.
The results may have implications for researchers who study the origins of when humans first domesticated horses—and also cast doubt on a long-standing theory in archaeology known as the Kurgan hypothesis.
He explained that the earliest, incontrovertible evidence of humans using horses for transport comes from the region around the Ural Mountains of Russia. There, scientists have uncovered horses, bridles and chariots dating back to around 4,000 years ago.
But the Kurgan hypothesis, which emerged in the early 20th century, argues that the close relationship between humans and horses began much earlier. Proponents believe that around the fourth millennium B.C., ancient humans living near the Black Sea called the Yamnaya first began galloping on horseback across Eurasia. In the process, the story goes, they may have spread a primordial version of the languages that would later evolve into English, French and more.
“A lot of our understanding of both the ancient and modern worlds hinges on when people started using horses for transportation,” Taylor said. “For decades, there’s been this idea that the distribution of Indo-European languages is, in some way, related to the domestication of the horse.”
Recently, scientists have pointed to human remains from the Yamnaya culture dating back to about 3500 B.C. as a key piece of evidence supporting the Kurgan hypothesis. These ancient peoples, the group argued, showed evidence of wear and tear in their skeletons that likely came from riding horses.
Hips can lie
But, in the new study, Hosek and Taylor argue that the story isn’t so simple.
Hosek has spent a lot of time poring over human bones to learn lessons about the past. She explained that the skeleton isn’t static but can shift and change shape over an individual’s lifetime. If you pull a muscle, for example, a reaction can emerge at the site where the muscle attaches to the underlying bone. In some cases, the bone can become more porous or raised ridges may form.
Reading those sorts of clues, however, can be murky at best. The hip joint is one example.
Hosek noted that when you flex your legs at the hip for long periods of time, including during long horse rides, the ball and socket of the hip joint may rub together along one edge. Over time, that rubbing can cause the round socket of the hip bone to become more elongated, or oval in shape. But, she said, other activities can cause the same kind of elongation.
Archaeological evidence shows that humans used cattle, donkeys and even wild asses for transport in some areas of western Asia centuries before they first tamed horses. Ancient peoples likely yoked these beasts of burden to pull carts or even smaller, two-wheeled vehicles that looked something like a chariot.
“Over time, this repetitive, intense pressure from that kind of jostling in a flexed position could cause skeletal changes,” Hosek said.
She’s seen similar changes, for example, in the skeletons of Catholic nuns from the 20th century. They never rode horses, but did take long carriage rides across the American West.
Ultimately, Hosek and Taylor say that human remains on their own can’t be used to put a date on when people first started riding horses—at least not with currently available science.
“Human skeletons alone are not going to be enough evidence,” Hosek said. “We need to couple that data with evidence coming out of genetics and archaeology and by looking at horse remains, too.”
Taylor added that the picture doesn’t look good for the Kurgan hypothesis:
"At least for now, none of these lines of evidence suggest that the Yamnaya people had domestic horses.”
A team of researchers from the University of Cape Town (South Africa) and the Max Planck Institute for Evolutionary Anthropology in Leipzig (Germany) have analysed human remains from the Oakhurst rock shelter in southernmost Africa and reconstructed the genomes of thirteen individuals, who died between 1,300 and 10,000 years ago, including the oldest human genome from South Africa to date.
“Oakhurst rock shelter is an ideal site to study human history, as it contained more than 40 human graves and preserved layers of human artefacts, such as stone tools, going back 12,000 years,” says Victoria Gibbon, Professor of Biological Anthropology at the University of Cape Town and co-senior author of the study. “Sites like this are rare in South Africa, and Oakhurst has allowed a better understanding of local population movements and relationships across the landscape over nearly 9,000 years.”
Long history of genetic stability in southernmost Africa
The successful genetic sequencing of thirteen individuals from the site was not without its challenges, as Stephan Schiffels, co-senior author of the study, explains: “Such ancient and poorly preserved DNA is quite difficult to sequence, and it took several attempts using different technologies and laboratory protocols to extract and process the DNA.” The ancient genomes represent a time series from 10,000 to 1,300 years ago, providing a unique opportunity to study human migrations through time and the relationship to the diverse groups of people living in the region today.
A key finding was that the oldest genomes from the Oakhurst rock shelter are genetically quite similar to San and Khoekhoe groups living in the same region today. This came as a surprise, as Joscha Gretzinger, lead author of the study, says: “Similar studies from Europe have revealed a history of large-scale genetic changes due to human movements over the last 10,000 years. These new results from southernmost Africa are quite different, and suggest a long history of relative genetic stability.” This only changed around 1,200 years ago, when newcomers arrived and introduced pastoralism, agriculture and new languages to the region and began interacting with local hunter-gatherer groups.
In one of the most culturally, linguistically and genetically diverse regions of the world, the new study shows that South Africa’s rich archaeological record is becoming increasingly accessible to archaeogenetics, providing new insights into human history and past demography.
Landmark new research shows Ice Age teens from 25,000 years ago went through similar puberty stages as modern-day adolescents. In a study published today in the Journal of Human Evolution of the timing of puberty in Pleistocene teens, researchers are addressing a knowledge gap about how early humans grew up.
Found in the bones of 13 ancient humans between 10 and 20 years old is evidence of puberty stages. Co-led by University of Victoria (UVic) paleoanthropologist April Nowell, researchers found specific markers in the bones that allowed them to assess the progress of adolescence.
“By analyzing specific areas of the skeleton, we inferred things like menstruation and someone’s voice breaking,” says Nowell.
The technique was developed by lead author Mary Lewis from the University of Reading. Lewis’s technique evaluates the mineralization of the canines and maturation of the bones of the hand, elbow, wrist, neck and pelvis to identify the stage of puberty reached by the individual at their time of death.
“This is the first time my puberty stage estimation method has been applied to Paleolithic fossils and it is also the oldest application of another method—peptide analysis—for biological sex estimation,” says Lewis.
Life during prehistory was believed to be as Thomas Hobbes described: “nasty, brutish and short.” However, this new study shows these teens were actually quite healthy. Most individuals in the study sample entered puberty by 13.5, reaching full adulthood between 17 and 22 years old. This indicates these Ice Age adolescents started puberty at a similar time to teens in modern, wealthy countries.
“It can sometimes be difficult for us to connect with the remote past, but we all went through puberty even if we experienced it differently,” says Nowell. “Our research helps to humanize these teens in a way that simply studying stone tools cannot.”
One of the 13 skeletons examined was “Romito 2,” an adolescent estimated to be male and the earliest known individual with a form of dwarfism. This new research on puberty assessment provides further information about Romito 2’s likely physical appearance and his social role.
Since he was mid-way through puberty, his voice would be deeper much like an adult male and he would have been able to father children; however, he may still have appeared quite youthful with fine facial hair. Due to his short height, his appearance would have been closer to that of a child, which may have had implications for how he was perceived by his community.
“The specific information about the physical appearance and developmental stage of these Ice Age adolescents derived from our puberty study provides a new lens through which to interpret their burials and treatment in death,” says archaeologist Jennifer French of the University of Liverpool, one of the co-authors of the study.
Researchers from six institutions collaborated internationally to develop this body of knowledge: UVic (Canada), University of Reading and University of Liverpool (UK), Museum of Prehistoric Anthropology of Monaco (Monaco), University of Cagliari (Italy) and University of Siena (Italy). The collaboration continues with research into the lives of Ice Age teenagers and their social roles.
This research was supported by the Social Sciences and Humanities Research Council, in addition to Nowell’s Lansdowne Fellowship Award.
A fossilized Neanderthal discovered in a cave system in the Rhône Valley, France, represents an ancient and previously undescribed lineage that diverged from other currently known Neanderthals around 100,000 years ago and remained genetically isolated for more than 50,000 years. Genomic analysis indicates that the Neanderthal, nicknamed “Thorin” in reference to the Tolkien character, lived between 42,000–50,000 years ago in a small, isolated community. The discovery, publishing September 11 in the Cell Press journal Cell Genomics,could shed light on the still-enigmatic reasons for the species’ extinction and suggests that late Neanderthals had more population structure than previously thought.
“Until now, the story has been that at the time of the extinction there was just one Neanderthal population that was genetically homogeneous, but now we know that there were at least two populations present at that time,” says first author and population geneticist Tharsika Vimala (@tharsikavimala) of the University of Copenhagen.
“The Thorin population spent 50,000 years without exchanging genes with other Neanderthal populations,” says co-first author and discoverer of Thorin, Ludovic Slimak, CNRS researcher of Université Toulouse Paul Sabatier. “We thus have 50 millennia during which two Neanderthal populations, living about ten days' walk from each other, coexisted while completely ignoring each other. This would be unimaginable for a Sapiens and reveals that Neanderthals must have biologically conceived our world very differently from us Sapiens.”
Thorin’s fossilized remains were first discovered in 2015 in Grotte Mandrin—a well-studied cave system that also housed early Homo sapiens, though not at the same time—and he is still being slowly excavated.
Based on Thorin’s location within the cave’s sediment, the team’s archeologists suspected that he lived around 40–45,000 years ago, making him a “late Neanderthal.” To determine his age and relationships with other Neanderthals, the team extracted DNA from his teeth and jaw and compared his full genome sequence to previously sequenced Neanderthal genomes.
Surprisingly, the initial genomic analysis suggested that Thorin was much older than the archeological age estimate because his genome was very distinct from other late Neanderthals and much more closely resembled the genomes of Neanderthals who lived more than 100,000 years ago.
“We worked for seven years to find out who was wrong—archeologists or genomicists,” says Slimak.
To solve this riddle, the researchers analyzed isotopes from Thorin’s bones and teeth to gain insight into what type of climate he lived in—late Neanderthals lived during the Ice Age, while early Neanderthals enjoyed a much warmer climate. The isotopic analysis showed that Thorin lived in a very cold climate, making him a late Neanderthal.
“This genome is a remnant of some of the earliest Neanderthal populations in Europe,” says population geneticist and senior author Martin Sikora of the University of Copenhagen. “The lineage leading to Thorin would have separated from the lineage leading to the other late Neanderthals around 105,000 years ago.”
Compared to previously sequenced Neanderthal genomes, Thorin’s genome most closely resembled an individual excavated in Gibraltar, and Slimak speculates that Thorin’s population migrated to France from Gibraltar.
“This means there was an unknown mediterranean population of Neanderthals whose population spanned from the most western tip of Europe all the way to the Rhône Valley in France,” says Slimak.
Knowing that Neanderthal communities were small and insular could be key to understanding their extinction because isolation is generally considered to be a disadvantage for population fitness.
“It's always a good thing for a population to be in contact with other populations,” says Vimala. “When you are isolated for a long time, you limit the genetic variation that you have, which means you have less ability to adapt to changing climates and pathogens, and it also limits you socially because you're not sharing knowledge or evolving as a population.”
However, to really understand how Neanderthal populations were structured and why they went extinct, the researchers say that more Neanderthal genomes need to be sequenced.
“I would guess that if we had more genomes from other regions during this similar time period, we would probably find other deeply structured populations,” says Sikora.
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This research was supported by the Service Regional de l’Archeologie Auvergne Rhone-Alpes, the French CNRS, the city of Malataverne, the Lundbeck Foundation and the Danish National Research Foundation, the European Research Council, and the Australian Research Council.
Cell Genomics (@CellGenomics) is a new gold open access journal from Cell Press publishing multidisciplinary research at the forefront of genetics and genomics. The journal aims to bring together diverse communities to advance genomics and its impact on biomedical science, precision medicine, and global and ecological health. Visit https://www.cell.com/cell-genomics/home. To receive Cell Press media alerts, please contact press@cell.com.
Rapa Nui or Te Pito o Te Henua (the navel of the world), also known as Easter Island, is one of the most isolated inhabited places in the world. Located in the Pacific, it lies over 1,900 km east of the closest inhabited Polynesian island and 3,700 km west of South America. Although the island, its inhabitants and their rich culture have been extensively studied by archaeologists, anthropologists and geneticists, two key elements of Rapanui history remain very controversial to this day. One of these is the theory of population collapse through "ecocide" or "ecological suicide" in the 1600s, thought to be the result of overpopulation and resource mismanagement. The other major contention is whether the Polynesian ancestors of the Rapanui interacted with Indigenous Americans before contact with Europeans in 1722.
This week's issue of Nature features a genetic study that sheds light on these two debates related to Rapanui history by examining the genomes of 15 Rapanui individuals who lived between 1670 and 1950. The remains of these 15 individuals are currently hosted at the Musée de l’Homme, in Paris. The new study was carried out by an international team of scientists and was spearheaded by Assistant Professor Víctor Moreno-Mayar from the Globe Institute at the University of Copenhagen (Denmark), and PhD student Bárbara Sousa da Mota and Associate Prof. Anna-Sapfo Malaspinas from the Faculty of Biology and Medicine at the University of Lausanne (Switzerland), in close collaboration with colleagues in Rapa Nui as well as in Austria, France, Chile, Australia and U.S.A.
The collapse that never happened
The story of the Rapanui has often been presented as a warning tale against humanity's over-exploitation of resources. After Polynesians from the west peopled the island by 1250, the landscape on Rapa Nui changed drastically. Towering stone statues—the moai—were carved and placed in all corners of the island, while its original forest of millions of palm trees dwindled and, by the 1600s, was all but gone. According to the "ecocide" theory, a population of over 15,000 Rapanui individuals triggered these changes that led to a period of resource scarcity, famine, warfare and even cannibalism culminating in a catastrophic population collapse.
"While it is well established that the environment of Rapa Nui was affected by anthropogenic activity, such as deforestation, we did not know if or how these changes led to a population collapse," comments Anna-Sapfo Malaspinas, Assoc. Professor at the University of Lausanne and group leader at the SIB Swiss Institute of Bioinformatics, Switzerland, last author of the study.
The researchers looked into the genomes of the Ancient Rapanui individuals expecting to find a genetic signature of a population collapse such as a sudden drop in genetic diversity. But surprisingly, the data did not contain any evidence of a population collapse in the 1600s.
"Our genetic analysis shows a stably growing population from the 13th century through to European contact in the 18th century. This stability is critical because it directly contradicts the idea of a dramatic pre-contact population collapse," says Bárbara Sousa da Mota, a researcher at the Faculty of Biology and Medicine at University of Lausanne and first author of the study.
Through their genetic analysis, Moreno-Mayar, Sousa da Mota, Malaspinas and their colleagues have not only provided evidence against the collapse theory, but also stress the resilience of the Rapanui population facing environmental challenges over several centuries until the colonial disruptions that European contact brought after 1722.
Did Polynesians reach the Americas?
Another debate that has tantalized researchers for decades is whether Polynesians ever reached the Americas. Although long-distance maritime navigation using wooden watercraft likely halted after the Rapa Nui forest disappeared, archaeological and genetic evidence from contemporary individuals hints that voyages to the Americas did occur. However, previous studies looking at small amounts of DNA from ancient Polynesians had rejected the hypothesis that transpacific voyages took place. Thus, these findings have put into question whether Polynesians reached the Americas and have suggested that the inferred contact based on present-day genetic data was mediated by European colonial activity after 1722.
By generating high-quality ancient genomes from the 15 Rapanui individuals, the team substantially increased the amount of genomic data from the island and found that about ten percent of the Rapanui gene pool has an Indigenous American origin. But more importantly, they were able to infer both populations met before Europeans arrived in the island and in the Americas.
"We looked into how the Indigenous American DNA was distributed across the Polynesian genetic background of the Rapanui. This distribution is consistent with a contact occurring between the 13th and the 15th centuries, " says first author Víctor Moreno-Mayar, Asst. Professor at the Globe Institute's Section for Geogenetics, University of Copenhagen.
"While our study cannot tell us where this contact occurred, this might mean that the Rapanui ancestors reached the Americas before Christopher Columbus,” says Malaspinas.
Altogether, the results from the new study help settle longstanding debates that have led to years of speculation surrounding Rapanui history.
"Personally, I believe the idea of the ecocide is put together as part of a colonial narrative. That is this idea that these supposedly primitive people could not manage their culture or resources, and that almost destroyed them. But the genetic evidence shows the opposite. Although we have to acknowledge that the arrival of humans dramatically changed the ecosystem, there is no evidence of a population collapse before the Europeans arrived on the island. So we can put those ideas to rest now," says Moreno-Mayar.
“Many thought that present-day Rapanui carry Indigenous American genetic ancestry due to European colonial activity. But instead, the data strongly suggests that Rapanui and Indigenous Americans met and admixed centuries before Europeans made it to Rapa Nui or the Americas. We believe this means that Rapanui were capable of even more formidable voyages across the Pacific than previously established, " adds Sousa da Mota.
Future repatriation efforts
Importantly, the scientists held face-to-face discussions with members of the Rapanui community and the "Comisión Asesora de Monumentos Nacionales" in Rapa Nui (CAMN). These discussions allowed to steer the research and to define a set of research questions that were equally of high interest to the scientists and the community. For instance, the team was able to show that the populations closest to the ancient Rapanui are indeed those currently living on the island.
"We have seen that museum archives contain mistakes and mislabels. Now that we have established that these 15 individuals were in fact Rapanui we know that they belong back in the island," says Moana Gorman Edmunds, an archaeologist in Rapa Nui and co-author of the study.
Furthermore, when ongoing results were presented to representatives of the Rapanui community, the need to repatriate their ancestors was discussed as a central goal for immediate future efforts.
"We now have a strong fact-based argument to start an important discussion about how and when these remains should be returned to the island. Furthermore, through the CAMN, the Rapanui community will stay in control of who gets the genetic data of our ancestors and what they use it for," adds Gorman Edmunds.
