The role of insects in the diet of our ancestors revealed

In recent years, human population growth, coupled with the climate crisis, environmental pressures, and current production and consumption patterns, has driven the search for alternative food sources. With 1,611 insect species listed as edible, organizations such as the Food and Agriculture Organization of the United Nations (FAO) have proposed insects as a sustainable food source. However, despite the fact that hundreds of millions of people already consume them, Western societies continue to show aversion to entomophagy. While this rejection may have a cultural basis, its origin remains unknown.

To explore its roots, a study by the Institute of Evolutionary Biology (IBE), a joint centre of the Spanish National Research Council (CSIC) and Pompeu Fabra University (UPF), has used genomic analyses to reconstruct insect consumption over the past thousands of years. The research, published in Science Advances, suggests that insect consumption was sporadic and accidental in Europe, Central and East Asia, while it would have been more frequent in tropical regions and among Neanderthal populations. The results shed light on human evolution, ecology, and current insect consumption.

Genomic analysis reconstructs the history of entomophagy in Eurasia

To find evidence of insect consumption, the IBE team analyzed 745 samples of dental calculus (tartar) from anatomically modern humans, dating back up to 33,000 years. Tartar preserves traces of DNA from the species regularly consumed in the diet. The dental analyses suggest that modern humans in northern Eurasia did not routinely practice entomophagy. The team also studied the human genes involved in the digestion of chitin, a component of the insect exoskeleton. In North Eurasian human populations, chitinase genes carry mutations that confer a reduced capacity to digest insect exoskeletons, a trait that has persisted for the last 9,000 years, since the advent of agriculture.

“The scarce presence of insects in the diet of northern Eurasians suggests that the absence of entomophagy is not solely due to recent cultural factors, but also to a long ecological and evolutionary history”, says Pablo Librado, principal investigator at the IBE who led the study.

Neanderthals may have consumed insects more frequently

Despite inhabiting the same environment, Neanderthals had a greater abundance of insect DNA in their dental calculus than anatomically modern humans. These levels in Neanderthals are comparable to those found in western chimpanzees, which rely on entomophagy to supplement their diet on the savanna, especially during periods of drought.

The most abundant DNA remains in Neanderthal tartar belong to Diptera, the insect group that includes flies and mosquitoes, with the latter being particularly prominent. These findings support a recent hypothesis about the regular consumption of animal carcasses infested with fly larvae. The abundance of mosquito remains reinforces the possibility that the carcasses of their prey were kept in ponds and marshy areas, where mosquitoes lay their eggs.

The study also revealed that Neanderthal chitinase genes facilitate better digestion of insects, as also observed in the only Denisovan specimen analyzed.

The genetic imprint of entomophagy persists in tropical populations

The team analyzed genes linked to the digestion of insect exoskeleton chitin. These genes are expressed in the stomach and encode the enzymes chitinase acid (CHIA) and chitobiase (CTBS). In both ancient and modern samples, the researchers identified genetic variants associated with a greater expression of these enzymes in populations inhabiting areas near the tropics.

“Large quantities of insects need to be ingested to compensate for the high caloric expenditure involved in their collection. In the tropics, there is a greater availability of social insects, such as termites and locusts: their biomass and diversity allow for sustainable exploitation throughout the year, which even contributes to pest control”, explains Manuel Piñero, a predoctoral researcher at the IBE and first author of the study.

The expression of these enzymes gradually decreased as populations moved towards higher latitudes. This latitudinal genetic variation, maintained for at least 9,000 years, reflects the abandonment of entomophagy in European populations.

The future of entomophagy in Europe

“Beyond cultural or religious factors, our results suggest that the reduced availability of insects in non-tropical areas may have been a key factor in the abandonment of entomophagy, leading to a reduced capacity to digest insect exoskeletons”, Librado comments.

However, modern industrial processing allows us to take advantage of the nutritional properties of the food source without needing to digest this component, in addition to allowing its mass production in edible insect farms.

The Ancient Population Genomics research group led by Pablo Librado at the IBE studies the domestication process, using insect species recently approved for human consumption as a model and by comparing the genomes of farmed insects with the genomes of pre-domestication individuals extracted from entomological collections. “We investigate the evolution of domestication in animals, which also gives us information to improve the exploitation of insects for consumption, both as animal feed and for human consumption”, Librado concludes.

CSIC Comunicación

comunicacion@csic.es 

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Journal

Science Advances

DOI

10.1126/sciadv.aec6939 

Study details epic transportation of Stonehenge stone across ancient Britain

Peer-Reviewed Publication

Curtin University

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Dr Anthony Clarke at Stonehenge

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Credit: Curtin University

New research by Curtin University has revealed how one of Stonehenge’s most mysterious stones was likely transported hundreds of kilometres across Britain through challenging terrain, highlighting the remarkable capabilities of ancient communities.

 

Stonehenge’s central Altar Stone is a six-tonne sandstone megalith now believed to have originated in northeast Scotland, around 700km from Salisbury Plain, underscoring the extraordinary scale of its journey.

 

The new study builds on earlier findings that ruled out glaciers as the sole mechanism for moving the stones, strengthening the conclusion people were responsible for transporting them across difficult terrain rather than relying on natural Ice Age processes.

 

Researchers have now focused on what that journey may have looked like, combining mineral grain dating with ice-sheet modelling to pinpoint the stone’s origin and test whether glaciers could have carried it south.

 

Co-lead author Dr Anthony Clarke, from the Timescales of Minerals Systems Group within Curtin’s School of Earth and Planetary Sciences, said the findings suggest the journey was far from simple and likely required careful planning across multiple stages.

 

“Rather than being carried naturally by ice, the evidence points to a deliberate, carefully planned movement across a challenging and varied landscape,” Dr Clarke said.

 

“Our modelling shows glaciers may have transported rocks part of the way during the last Ice Age — potentially as far as Dogger Bank in the North Sea — but not into southern England, meaning the stone would still have needed to be moved hundreds of kilometres by people.

 

“The research indicates there were no viable glacial pathways linking the source region directly to Stonehenge, reinforcing the conclusion that human transport was required.

 

“Instead, this suggests the stone was likely moved in stages, potentially combining overland hauling with river or coastal transport where possible.”

 

Dr Clarke said the findings reveal a level of organisation and cooperation among Neolithic communities not previously fully appreciated.

 

“Transporting a stone of this size over such a long distance would have required planning, coordination and a deep understanding of the landscape – not to mention tremendous determination,” Dr Clarke said.

 

“The study demonstrates how combining geological analysis with computer modelling can help resolve long-standing questions about how Stonehenge was built.”

 

Future research will aim to pinpoint the Altar Stone’s exact source in northeast Scotland and further investigate possible transport routes used by prehistoric communities.

 

The research was conducted in collaboration with experts from Sheffield Hallam University, the University of Sheffield, Wessex Archaeology, and the University of Bristol in the United Kingdom.

 

The study, ‘From Highlands to Henge: Refining the Provenance and Transport Pathways of Stonehenge’s Altar Stone’ (DOI:10.1002/jqs.70080), was published in the Journal of Quaternary Science.

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Journal

Journal of Quaternary Science

DOI

10.1002/jqs.70080 

Ice Age mystery: Taimering mammoth was likely butchered by hunters and gatherers

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The mammoth’s tusk at the excavation site in Taimering. (Photo: BLfD)

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Credit: BLfD

Six years ago, during construction work in Taimering near Regensburg (Bavaria, Germany), employees of the Bavarian State Office for the Preservation of Historical Monuments (BLfD) discovered a nearly 2.5-meter-long, spirally twisted tusk that belonged to a woolly mammoth, Mammuthus primigenius. Nearby, the archaeologists also found over 70 additional bones and bone fragments, primarily from the ribcage as well as hand and foot bones. Most of the long bones of the large mammal are missing. “The mammoth’s tusk and bones were exceptionally well-preserved due to their millennia-long conservation in the wet soil environment,” says Dr. Christoph Steinmann, deputy head of the Department of Archaeological Heritage Preservation for Lower Bavaria/Upper Palatinate at the BLfD. After its recovery, the find was prepared at the Bavarian State Collections of Natural History (SNSB), and further scientific investigations were coordinated from there.

The palaeontological assessment revealed that all the bones, as well as the tusk, belong to a single, very large but not yet fully grown individual with a shoulder height of about three meters. The Taimering woolly mammoth likely died directly at or at least near its discovery site. The bone surfaces, which have been preserved intact down to the finest detail, rule out both prolonged transport by water and disarticulation by predators. According to the researchers, the animal was buried in the sediments of a pond or a slow-flowing tributary of the prehistoric Danube River during the Ice Age. Radiocarbon dating indicates a geological age of the bones between 27,000 and 25,000 years ago.

Unusual markings on the surface turned out to be cut marks and provide clear evidence of human activity. Numerous such indentations are found exclusively on the ribs—made by Palaeolithic hunters and gatherers who butchered the animal. One of the broad rib bones was even used as a cutting board. Whether the mammoth was killed by humans or had already been dead when people processed the carcass remains unclear, according to lead author Kerstin Pasda from the Institute of Prehistory and Early History at the Friedrich-Alexander-University Erlangen-Nürnberg (FAU), who conducted the osteoarchaeological analyses of the anthropogenic modifications.

Pollen analyses conducted by Dr. Philipp Stojakowits at the University of Augsburg reveal a great deal to the researchers about the habitat in which the mammoth lived and died. They indicate a herbaceous, tundra-like steppe vegetation with scattered dwarf shrubs. The so-called Mammoth Steppe was a vast treeless ecosystem in Eurasia that, during the peak of the last glacial period from 30,000 to 20,000 years ago, stretched across Europe between the Scandinavian ice sheet and the southern glaciers of the Alps. Its nutrient-rich grasses and dwarf shrubs provided food for a variety of large mammals, including the Taimering mammoth.

The discovery is exceptional in many respects. “First of all, mammoth skeletal remains are extremely rare in our latitudes. We are familiar with finds mainly from regions of Eurasia further to the east,” says PD Dr. Gertrud Rößner, a palaeontologist at the Bavarian State Collections of Natural History. “On the other hand, there is virtually no evidence of human activity in this region from that peak period of the Ice Age. Due to climate change, hunter-gatherer communities in Europe retreated southward and eastward,” add archaeology professors Andreas Maier of the University of Cologne and Thorsten Uthmeier of FAU Erlangen-Nürnberg.

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Journal

Journal of Archaeological Science

DOI

10.1016/j.jasrep.2026.105839 

Ötzi and his microbiome: a 5,300-year-old relationship

Researchers at Eurac Research have obtained a detailed picture of the microbial community associated with Ötzi. The study provides insights into a complex microbiome, ranging from the gut flora of a Copper Age human to cold-adapted yeasts

Peer-Reviewed Publication

Eurac Research

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The Iceman mummy is preserved in a refrigeration chamber at a constant temperature of -6°C and a relative humidity of 99% .

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Credit: South Tyrol Museum of Archaeology/Eurac Research/Marion Lafogler

Using a variety of samples and methods, the researchers were able to differentiate which microorganisms were already present in the body during his lifetime and which only colonized it after his death – both during the time in the glacier and over three decades of preservation. In samples of internal tissue, the researchers were able to detect genetic material from bacteria belonging to Ötzi’s original gut flora. A surprising finding is the presence of cold-adapted yeast species, likely originating from the glacial environment, that have persisted on Ötzi’s body to the present day. These cold-tolerant yeasts may also hold potential for industrial applications. The study was published in the reputable Microbiome journal.

It was an extensive investigation, in which the research team analyzed ice from the surface as well as meltwater from inside the mummy and collected numerous samples by swab. Data from intestinal tissue and stomach contents were available from previous studies. A soil sample from the discovery site, collected and frozen during Ötzi’s recovery in 1991, was also analyzed to trace environmental influences. Researchers also identified genetic material from the original gut microbiome in the intestinal tract and stomach content. This microbiome, first described in a 2019 study conducted with Eurac Research, closely resembles the few known examples of gut flora from early human populations – such bacteria are rarely found in the intestines of modern humans living in industrialized societies. Ötzi therefore offers a rare glimpse into humanity’s microbial past.

The newly discovered yeasts were isolated from skin samples, meltwater from inside the mummy, and samples of stomach content. Such highly specialized species have adapted to cold temperatures. Genetic analyses revealed a relationship with strains from extremely cold regions such as Antarctica. This suggests that the yeasts originate from the glacial environment and may have been associated with the mummy for thousands of years. The researchers found both heavily degraded (ancient) and well-preserved (modern) DNA. This indicates that these microorganisms are not merely relics of the past but continue to exist under today’s preservation conditions at minus six degrees Celsius and with high humidity—possibly in a dormant state. “We see continuity here,” explains Frank Maixner, director of the Institute for Mummy Studies at Eurac Research: “These yeasts have accompanied Ötzi on his long journey through the millennia.” According to Maixner, this shows that the mummy is “not a static relic, but a dynamic biological system.”

The study also shows that earlier conservation measures may have unintentionally favored certain microorganisms: three of the four yeasts possess the genetic capacity to break down phenol—an active ingredient used after Ötzi’s recovery to rid the mummy’s surface of fungal growth which the yeasts may have been able to use as a food source.

“A mummy’s microbiome is unique because we are dealing with microbes that are over 5,000 years old and, at the same time, with modern microbes that have been introduced since the discovery,” says microbiologist and lead author Mohamed S. Sarhan.

“The mummy’s conservation conditions are very stable today,” comments Elisabeth Vallazza, director of the South Tyrol Museum of Archaeology that oversees the mummy’s conservation, “close microbiological monitoring ensures that the mummy suffers no damage. But further research and full conservation efforts are certainly needed to preserve it for many more generations.”

Conservation expert and co-author Marco Samadelli emphasizes: 'The conditions under which glacial mummies are preserved are not yet fully understood. This study expands our knowledge in this area.”

In addition to the significance for the preservation of the mummy, the findings also open new avenues for research: cold-adapted microorganisms could, for example, be used in energy-efficient industrial processes, such as low-temperature fermentation.

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Journal

Microbiome

DOI

10.1186/s40168-026-02417-6 

Neandertal ancestry influences our immune system in more ways than previously recognized

 Researchers find surprising links which show that Neandertal ancestry influences our immune system today in ways more nuanced than previously recognised. 

Viruses account for an estimated 10-20% of the global disease burden. Many DNA viruses can persist in the body for a lifetime, and virus load varies greatly even among people without symptoms. Throughout human history, they have posed persistent and rapidly evolving threats, placing strong adaptive pressure on our immune system. Previous research has shown that many genetic variants involved in immunity bear the marks of these evolutionary battles - including signatures of natural selection and contributions from interbreeding with archaic humans. While Neandertal ancestry has previously been associated with beneficial effects in RNA virus defence, the new study highlights a contrasting trend for DNA viruses.

Because of past admixture with archaic humans, around 2% of the genomes of present-day non-Africans is composed of Neandertals DNA and an additional 2-4% of people in Oceania of Denisovan ancestry These introgressed sequences have shaped many biological traits, including immunity. But their role in defences against DNA viruses has remained largely unexplored.

Modern disadvantages don’t imply ancient harm

RNA and DNA viruses differ fundamentally in their biology - including infection strategies, tissue tropism, and the pace at which they evolve. These differences raise the possibility that the effects of archaic genetic variants on DNA and RNA virus response might differ. To investigate this, the team explored the contribution of archaic DNA - primarily Neandertal ancestry - to the DNA viral load of participants in the UK Biobank. By analysing viral sequences detected in large-scale genomic data, the researchers asked whether archaic variants correlate with the presence or quantity of common DNA viruses.

The study uncovered multiple associations between archaic DNA and the loads of Epstein-Barr virus (EBV), Human Herpesvirus 7 (HHV‑7), and anelloviruses of the Teno family. These viruses are widespread in humans and often persist as chronic infections. Overall, archaic DNA was disproportionally often associated with higher virus loads. These viruses often cause no symptoms, but the amount of viral DNA can reflect how effectively the immune system keeps them in check.

“Our results suggest that Neandertal-derived variants may not provide effective defense against several DNA viruses in people today,” said Michael Dannemann, a co-author of this study. “This stands in striking contrast to their previously reported beneficial effects on RNA virus immunity.” However, the researchers emphasise that these negative effects in present-day populations do not mean that the same variants were harmful to Neandertals themselves. “Viruses evolve extremely quickly,” noted Dannemann.

“The pathogenic landscape faced by Neandertals tens of thousands of years ago would have been vastly different from the one we face today. A variant that reduced viral burden in the past may increase it now.” Supporting this idea, the team identified genomic regions carrying archaic variants that show shifts in selective pressure over time, including signatures of more recent negative selection. These evolutionary signals align with the possibility that once-beneficial archaic alleles have become disadvantageous in today’s environments.

The findings highlight that archaic DNA in people today interacts with modern pathogens in distinct ways - and that its effects can differ sharply between virus classes. The work underscores that archaic genetic ancestry still influences our immune system today - but in ways more nuanced than previously recognised.

Read more: https://academic.oup.com/gbe/article/18/5/evag110/8664352 

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Journal

Genome Biology and Evolution

DOI

10.1093/gbe/evag110 

South American Indigenous peoples are diverse and descend from a third wave of migration

 The Indigenous peoples of South America are descended from three waves of migration. According to a study conducted exclusively by researchers from the continent, one of these waves, which is most represented in the current population, came from Mesoamerica around 1,300 years ago. This finding reveals the greater complexity of the history of Indigenous peoples and their greater genetic diversity than previously anticipated. The research is featured on the cover of the May 7 issue of the scientific journal Nature. “We reached these conclusions through very intensive collaborative work,” says Tábita Hünemeier, a geneticist at the Institute of Biosciences at the University of São Paulo (IB-USP) in Brazil. She coordinated the study, on which she has been working for over a decade, and was surprised by the higher-than-expected genetic diversity.

A total of 128 genomes were fully sequenced and compared to 71 other sequences available in databases. The genomes represented 45 Indigenous groups from eight Latin American countries: Argentina, Bolivia, Brazil, Colombia, Ecuador, Mexico, Paraguay, and Peru. The goal was to estimate the genetic affinities among all Indigenous American groups by taking ancient genomes into account. The researcher celebrates the inclusion of biomedical scientist Putira Sacuena from the Federal University of Pará (UFPA), among the authors. “She was the first Indigenous woman to work in genetic anthropology,” Hünemeier states. The researchers consider Indigenous collaboration in studies concerning native peoples to be a welcome development in the quest to understand their history.

This work adds important information to what is known about the human colonization of South America. The first wave of migration left records dating back up to 12,000 years ago at Lapa do Santo (read more at revistapesquisa.fapesp.br/en/the-peoples-of-lagoa-santa/) and in the Sumidouro cave in the Lagoa Santa region of Minas Gerais state in Brazil, as well as in Chile. Around 9,000 years ago, another migration left distinct marks in the genetic and archaeological record in Peru and Argentina. However, the Middle Holocene period, between 8,000 and 4,200 years ago, brought environmental changes that damaged ecosystems and reduced the availability of resources, affecting human populations as well.

The Indigenous peoples inhabiting the continent today are partly descended from individuals who arrived from what is now Mexico about 1,300 years ago. This third wave had not been documented until now and is a major new finding. DNA analyses also suggest that Indigenous groups became less populous and more isolated from one another after the arrival of Europeans in the 16th century. The study detected signs of inbreeding – which occurs when reproduction happens among small groups with no possibility of migration – among the Sirionó, Suruí, and Karitiana peoples within the Tupi lineage. This indicates a population collapse, which was likely caused by epidemics, enslavement, and disruptions to subsistence and traditional knowledge. A recent recovery can be observed in some regions of western South America. Genetic diversity is higher in Central America and the Southern Cone.

A puzzling discovery was the presence of ancient genomic segments characteristic of Australasians (people from Australia and surrounding islands), Neanderthals (from Europe), and Denisovans (from East Asia) in South American DNA. The hypothesis is that these ancient genes play a beneficial, as yet unknown, role and were maintained by natural selection. While the article focused on diversity and population trajectories rather than functional aspects, the identification of regions associated with immune response, cardiometabolic traits, fertility, and anthropometric traits suggests that future studies may explore the role of human evolution on the continent in greater depth. According to Hünemeier, genetic markers used in previous studies were designed based on European and African populations, making them unsuitable for understanding the Americas. “Now we have parameters”.

Importantly, the study documented the prolonged presence of human groups with marked genetic diversity in many areas, which contradicts some views about Indigenous groups. This underscores the need for more comprehensive representation of these peoples in global genomic databases. “The whole world had genomic data to tell the story of its population; only Brazil didn’t,” says André Strauss, an archaeologist at the Museum of Archaeology and Ethnology (MAE) at USP who did not participate in the study. He refers to an article he published in 2018 in the journal Cell on the ancient history of the South American population (read more at revistapesquisa.fapesp.br/en/when-indigenous-people-occupied-lagoa-santa/). The article left a mystery hanging: If the people of Lagoa Santa were not the direct ancestors of today’s Indigenous peoples, who are their ancestors? “The current article confirms the two previous migratory waves and characterizes the third.”

Strauss aims to identify this wave in the archaeogenetic record. “Most of the skeletons we have are older. There are very few from pottery-making groups,” he explains. One reason for this is that caves and sambaquis are environments that are more conducive to the preservation of skeletons. In places like the Amazon, however, they decompose. Based on the available molecular data, more information is on the way. “We already have over a thousand more sequenced samples,” says Hünemeier. “We understand that to grasp the diversity and complexity of the Americas, it’s best to have a few individuals from many populations.

Ancient DNA reveals web of marriage and migration in Peru

 

Long-distance movement, intermarriage and kinship shaped ancient Andean coastal networks before the Inca Empire, new research finds

Peer-Reviewed Publication

University of Sydney

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Fig. 1 | Map of the study area. A. Locations of the Chincha Valley and other Andean sites referenced in this study that yielded ancient DNA data. B. The archaeological sites under investigation for this study. Basemaps for panels A and B were obtained from the World Imagery dataset (https://www.arcgis.com/home/item.html?id=10df2279f9684e4a9f6a7f08febac2a9) and created with ArcGIS Pro v3.6.2. Sources: ESRI, Michael Bauer Research GmbH 2022, Instituto Nacional de Estadística e Informática (INEI), Earthstar Geographics, Vantor. 

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Credit: Basemaps for panels A and B were obtained from the World Imagery dataset (https://www.arcgis.com/home/item.html?id=10df2279f9684e4a9f6a7f08febac2a9) and created with ArcGIS Pro v3.6.2. Sources: ESRI, Michael Bauer Research GmbH 2022, Instituto Nacional de Estadística e Informática (INEI), Earthstar Geographics, Vantor.

 

Long-distance migration along Peru’s Pacific coast began at least 800 years ago, centuries before the rise of the Inca Empire and much earlier than previously thought, a new international study reveals. 

By analysing ancient DNA (aDNA) alongside archaeological and historical data, the study provides some of the strongest evidence to date of population movement along the Pacific coast prior to Inca rule (AD 1400 to 1532), demonstrating that pre-Inca coastal communities were far more mobile and connected at local and interregional scales than historically believed. 

Published in Nature Communications, it suggests people travelled more than 700 kilometres from Peru’s north coast to the Chincha Valley in the south. Here, they settled and intermarried with neighbouring populations, while maintaining distinctive cultural traditions – such as cranial modification and painting the dead with red pigment – for generations. The study also identified a single grave containing relatives who engaged in endogamy, or close-kin procreation.  

“Migration and kinship have long been part of the human story and the development of powerful societies,” said co-lead author Dr Jacob Bongers, digital archaeologist and member of the Vere Gordon Childe Centre at the University of Sydney, and Visiting Research Fellow at the Australian Museum Research Institute.  

“What’s most interesting about this research is that it shows the close-knit and far-reaching social networks of pre-Inca coastal communities, as well as how people maintained cultural traditions of marking group identities for centuries, even as they intermarried with distinct groups,” he said. 

Tracing ancient movement and mating patterns through aDNA  

The research team analysed aDNA samples of 21 individuals recovered from burial sites in the Chincha Valley to reconstruct family relationships and explore genetic diversity over time.  

“The genome-wide data and radiocarbon dates suggest migrants arrived in the Chincha Valley by at least the thirteenth century AD, well before Inca expansion,” Dr Bongers said. “Their ancestry traced back to the Peruvian north coast, more than 700 kilometres away, and the aDNA of these early migrants revealed no evidence of mixing with local populations.” 

Genetic evidence revealed mixed ancestry between people from the north, central and south coasts over subsequent generations. “This likely means that, after northerners migrated to Chincha, they intermarried with groups from neighbouring coastal areas, a practice that continued during the Spanish Colonial Period (AD 1532-1825),” Dr Bongers said.  

Genetic and bioarchaeological data from the aDNA samples also indicated close-kin procreation.  

“The burial of family members together and the evidence for close-kin unions in the lower Chincha Valley highlights the importance of the familial unit for ancient Andeans,” said co-lead author Assistant Professor Jordan Dalton from the State University of New York, Oswego. 

“The close biological relationships suggest the sampled individuals were members of an ayllu or parcialidad, a traditional, kin-based group that shares common territory, resources and ancestry. Close-kin unions may have served as a strategic means of retaining control over resources within the group,” she said.  

Cultural traditions endured across centuries    

All sampled individuals had some north coast ancestry, demonstrating population continuity for at least 200 years. This coincides with persistent cultural traditions maintained in Chincha from at least the thirteenth to fifteenth centuries. 

“In the sampled individuals from the lower and middle valley we observed practices such as cranial modification, a process carried out in infancy to shape the head using boards and bindings, human vertebrae strung on reed sticks, and the postmortem application of red pigment to the skull,” Dr Bongers said.  

“Postmortem red pigment application and cranial modification are cultural traditions that have long been documented on Peru’s north coast, so this evidence shows migrants may have brought their body modification traditions south to mark group identities." 

The timing of migration from northern Peru aligned with major social and political changes along Peru’s coast, yet the precise reasons for population movement remain uncertain, Dr Bongers said. 

“Climate hazards, the expansion of powerful northern polities such as the Chimú, and access to valuable resources including seabird guano, are all possible drivers of ancient Andean migration,” he said. 

"Importantly, this research expands our understanding of how and when interregional interaction occurred along the Andean Pacific coast and makes it clear the Inca incorporated highly mobile and deeply connected coastal communities into their empire."