The lost golden age of language diversity

New modelling suggests that tens of thousands of languages were spoken between 1,000 and 3,000 years ago - and that their decline began well before European colonial expansion

Peer-Reviewed Publication

Max Planck Institute for Evolutionary Anthropology

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

Contemporary languages and endangerment status. Made with a Natural Earth base map using data from Glottolog 5.3 and information adapted from GlottoScope.

view more 

Credit: © Claire Bowern

To the Point

• Fewer languages before agriculture: The researchers estimate that between approximately 4,500 and 6,200 languages were spoken at the beginning of the Holocene, around 12,000 years ago - probably fewer than the roughly 7,500 languages spoken and signed today.

• A linguistic “golden age”: As the global human population grew, language diversity also increased. The models suggest that tens of thousands of languages may have existed between 1,000 and 3,000 years ago.

• A deep history of language loss: The decline in linguistic diversity appears to have begun with the expansion of large states and empires, long before modern European colonialism.

• Today’s languages are survivors: The languages spoken today represent a small and historically biased sample of past linguistic diversity, with important implications for how researchers explain global patterns in language and culture.

Today, people speak or sign around 7,500 languages. Yet this figure provides only a snapshot of a constantly changing history. How many languages existed before written records? Did agriculture reduce linguistic diversity by allowing expanding farming populations to replace smaller hunter-gatherer groups? Or did population growth initially create more opportunities for new languages to emerge?

An international research team involving researchers from Spain, the USA and Germany have reconstructed plausible trajectories of global language diversity across the last 12,000 years. Their study, published in Science, suggests that language diversity increased for most of the Holocene, reached a remarkable peak between approximately 1,000 and 3,000 years ago, and then declined rapidly thereafter.

Reconstructing a history without written records

“This paper presents an innovative approach to understanding the dynamics of human cultural diversity in the past, addressing one of the central yet least accessible questions in the human sciences. Progress has been limited not by a lack of theoretical interest but by the exceptional difficulty of observing the relevant dynamics empirically”, says Marcus Hamilton of the University of Texas at San Antonio.

Direct evidence for the number of languages is almost entirely absent before the appearance of writing around 6,000 years ago, and remains fragmentary until quite recently. The researchers therefore combined ethnographic information, estimates of prehistoric population size, and statistical and social-computational modelling.

They began with ethnographic data from 171 hunter-gatherer and fisher societies whose traditional subsistence and mobility had not been profoundly transformed by contact with food-producing populations. These data allowed the researchers to estimate the likely distribution of ethnolinguistic group sizes near the beginning of the Holocene.

The team then combined these estimates with reconstructions suggesting that the global human population 12,000 years ago was between approximately 4.4 and seven million. Assuming that ethnolinguistic groups at that time generally corresponded to distinct languages, the models produced an early-Holocene estimate centred on roughly 4,500 to 6,200 languages, although broader plausible estimates ranged from around 3,300 to 7,800.

“One of the first surprises was that the world immediately before agriculture was probably not exceptionally rich in languages. There were most likely fewer languages than there are today. Linguistic diversity then grew alongside the human population for thousands of years”, says Russell Gray, Director of the Department of Linguistic and Cultural Evolution at the Max Planck Institute for Evolutionary Anthropology in Leipzig.

Tens of thousands of languages

Agriculture, technological innovation and more stable food production allowed the global population to expand dramatically. At the same time, however, societies became larger, meaning that progressively more people could share the same language.

To capture these opposing processes, the researchers modelled thousands of possible trajectories connecting estimates at the beginning of the Holocene with the present. The models allowed the number of people per language to increase over time, while incorporating independent reconstructions of global population growth.

Although the precise trajectory remains uncertain, the models consistently produced a striking general pattern. Language diversity increased over most of the Holocene and typically peaked between 1,000 and 3,000 years ago. Many trajectories imply an approximately tenfold increase from early-Holocene levels, placing the peak number of languages in the tens of thousands.

“The most unexpected result is how recent the peak appears to have been. The period of greatest linguistic diversity may have occurred not in the remote Palaeolithic, but during the era of expanding states and early empires”, says Claire Bowern of Yale University.

The authors describe this period as a linguistic “golden age”. It has largely escaped previous discussion because most surviving historical records were produced by the expanding societies whose languages eventually became dominant.

Language loss before modern colonialism

The linguistic golden age was followed by a rapid decline, particularly during the last two millennia. The results therefore challenge the view that the present language-endangerment crisis began only with European colonial expansion around 500 years ago.

European colonialism unquestionably intensified language replacement on an enormous scale. The new models suggest, however, that the process had deeper roots in the expansion of earlier multinational states and empires. Such expansions brought previously separated populations into sustained contact and spread dominant languages together with political institutions, technologies, cultural practices and pathogens.

The model does not identify which particular empires, regions or historical events caused the global decline. Rather, it shows that a very large reduction in linguistic diversity must have taken place before the present.

Today’s languages passed through a bottleneck

This loss means that the languages spoken today are not a representative sample of those that once existed. Languages associated with expanding populations were disproportionately likely to survive, while the languages of absorbed, displaced or declining populations disappeared.

This historical bottleneck may also have altered the global frequency of grammatical structures, speech sounds and other linguistic features. Researchers often explain common features by suggesting that they are especially easy to learn, efficient to communicate or well suited to human cognition. The new study suggests that demographic expansion and extinction must also be considered.

“The languages we see today are the survivors of a massive and highly selective historical bottleneck. A linguistic feature may be common not because it is inherently superior, but because it happened to be carried by populations that expanded. Extinction may have shaped linguistic diversity much more profoundly than we previously appreciated”, says Damian Blasi, lead author of the study and researcher at the Catalan Institution for Research and Advanced Studies (ICREA) and Harvard University.

Because languages are often transmitted together with religious practices, kinship systems, social institutions and other forms of cultural knowledge, the authors argue that this bottleneck extended beyond language. Many cultural traditions may also have vanished without leaving direct historical evidence.

A model, not a prehistoric census

The researchers emphasise that the study provides a coarse global reconstruction rather than a direct count of prehistoric languages. Its estimates depend on assumptions about early ethnolinguistic group sizes and the long-term relationship between population and language numbers. Regional histories undoubtedly differed, and short-term collapses caused by warfare, disease and environmental disruption cannot be individually reconstructed by the model.

Nevertheless, the central pattern persisted across a wide range of modelling conditions and alternative assumptions. The results suggest that the history of language diversity was not a simple, continuous decline from a highly diverse Palaeolithic world. Instead, linguistic diversity rose with human population growth, reached an extraordinary but short-lived peak, and then underwent a severe global contraction.

---

Journal

Science

DOI

10.1126/science.adx4343 

 

Avocados in Nicaragua that people transported from South America thousands of years ago

 

A team of scientists led by researchers with the Smithsonian’s National Museum of Natural History and Texas A&M University recently uncovered genetic traces of ancient migration in DNA from avocados growing in Nicaragua. They found evidence that, around 5,000 years ago, people migrating north from South America carried the oversized seeds of one of their favorite fruits—avocados. As these seeds were dispersed throughout the humid lowlands of Central America, they hybridized with native varieties, producing a diversity of avocado varieties that produce the large, smooth-skinned berries that are now enjoyed around Central America. Despite resembling the avocados found in humid regions like Florida and the Caribbean, these local varieties are genetically distinct from the commercially grown fruits found in guacamole.

            In a paper published today, July 22, in the journal Plants, People, Planet, a team led by archaeobotanist Kevin Wann, who conducted the research as a fellow at the museum, examined DNA from avocado leaves collected in Nicaragua, Honduras and southern Mexico. They also spoke with the farmers and gardeners to learn how they cultivate these local avocados.

            “There is a much wider breadth of avocado diversity that science had not yet documented,” said Wann, who is now pursuing his doctorate in the Department of Anthropology in the College of Arts and Sciences at Texas A&M and had never eaten an avocado before this project. “We could potentially tap into this genetic diversity to conserve commercial avocado plants that are vulnerable to disease.”

A Crop of Clones

            The natural range of avocado trees (Persea americana) extends from Mexico to Peru. For more than 10,000 years, humans in this area have coveted the plant’s fruit, whose yellowish-green flesh is packed with nutrients and fats. These superfoods are now cultivated around the world—in 2024, growers produced more than 11 million metric tons of avocados.

            More than 80% of these avocados were a single variety known as the Hass avocado. These large, long-lasting avocados are produced through clonal grafting, where a branch is taken off one Hass avocado tree and attached to another tree to bear the same exact fruit. As a result, most avocados in grocery stores are genetically indistinguishable. This makes all Hass avocados vulnerable to the same threats. A single disease or change in temperature or precipitation can wipe out an entire population of Hass avocados.

            Increasing the genetic diversity of avocados is crucial to protecting this multi-billion-dollar industry. According to Wann, the muggy lowlands of countries like Nicaragua and Honduras are rich in avocado diversity. Here, traditional agricultural practices have honed the region’s native avocado varieties, also known as landraces, for thousands of years.

A Hotbed of Avocado Diversity

            To document the diversity of avocado landraces in Central America, Wann and his colleagues collected leaf samples from dozens of varieties in southern Mexico, Nicaragua and coastal Honduras. During the field work in southern Mexico, Wann dealt with bouts of food poisoning and was stung in the face by a wasp while collecting samples from a roadside grove of avocado trees.

            The researchers also interviewed local gardeners and rural farmers in Nicaragua and Honduras to learn more about native avocado varieties. This agricultural perspective was crucial according to Logan Kistler, the museum’s curator of archaeobotany and archaeogenomics who advised Wann during his fellowship and was the senior author of the new paper.

            “You can't think about biodiversity without considering agriculture, because it's one of the most impactful ecological activities we do,” Kistler said. “Traditional agricultural practices have shaped these plants for thousands of years.”

            During a tour of one grove in Nicaragua, a farmer offered Wann an avocado, unaware that the scientist had never tasted the fruit he studied.

            “I wanted to see how far I could go into my dissertation studying avocados without ever eating one,” he said. “I made it four years but when one of the native farmers offered me one, I couldn’t turn him down.

            “And it was delicious,” adds Wann, who now routinely enjoys guacamole.

            The locals shared valuable insights with the researchers. They confirmed that these lowland avocado landraces had not experienced root rot, the most common disease affecting commercial avocados. Some Nicaraguan farmers even graft commercial avocado branches onto native avocado trees, which are better adapted to the local environment.

Ancient Genetic Clues

            In the lab, the team extracted and analyzed DNA from the harvested leaf samples. In total, the team collected DNA from 47 native avocado landraces (32 of which came from Nicaragua). The scientists compared the DNA from the various landraces with previously published genetic data from more than 200 other avocado lineages.

            The team discovered that the avocado samples collected in southern Mexico were closely related to ancestral highland populations found in other parts of Mexico as well as commercial varieties. In contrast, the landraces sampled in the lowlands of Nicaragua were genetically tied to avocados found further south, including populations along the coast of Colombia.

            This revealed that many local landraces in this part of Central America are planted from fruits originally grown in South America. The team posits that human populations brought their local avocado varieties with them as they migrated through the Americas. Based on the genetics, this avocado relocation likely occurred around 5,000 years ago, which is roughly when other South American crops, like chocolate and certain varieties of maize, appear in the Central American archaeological record.

            Kistler thinks varieties of this fleshy fruit continued to move back and forth as ancient communities migrated over thousands of years.

            “It was a very connected landscape throughout Central and South America,” Kistler said. “It's not one big episode of people moving avocados and other food species around, it's a constant interchange.”

The Fruit’s Future

            Wann thinks the trove of avocado diversity preserved in Central America’s lowlands could help protect commercial avocados from the fate of other clonal crops like bananas, which have been devastated by fungal pathogens in the past. The region’s local landraces are also adapted to warmer and wetter climates.

            However, some of these local avocado varieties are at risk. Wann and his colleagues heard that several Nicaraguan farmers have cut down some of their local avocado trees to make more space for commercial varieties. Decreasing this ancient avocado diversity could threaten the fruit’s future.

            “These locally grown fruit trees are vital to the longevity of avocados as a species,” Wann said. “Their high levels of genetic diversity makes them more prepared to face potential shifts in climate or diseases compared to the ones you’d buy at a supermarket.”

Maize was likely "nutritionally and symbolically central" to the diet of many ancient Maya peoples

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

Upper image: The archaeological site of Curucuitz, in southeastern Peten, Guatemala, where maize is still grown today. Lower image: The A-630 vessel from Ixtutz, depicting four individuals, arranged in pairs, sharing the contents of a pitcher.

view more 

Credit: Proyecto Atlas Arqueológico de Guatemala, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)

Maize was likely "nutritionally and symbolically central" to the diet of many ancient Maya peoples, per analysis of bone and teeth samples from Petén, Guatemala

Article URL: https://plos.io/4plH2UW

Article title: Profiling the diets of Classic Maya communities living in Southeastern Petén through stable isotope analysis

Author countries: Mexico, USA, Guatemala.

Funding: This work was supported by the SECIHTI (formerly CONAHCYT) Ciencia de Frontera No. 61526 Project titled “Understanding the sensorial experience of Ancient and Modern Maya. New Archaeometric Studies of the Organic Compounds of Foods and Fragrances” and the SECIHTI Postdoctoral Grant “Estancias posdoctorales por México 2022 (1) (CVU 383572)”. Additional support for the UNM Research stay was obtained through the UC MEXUS collaborative project CN-19-128. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

---

Journal

PLOS One

DOI

10.1371/journal.pone.0353029 

Article Title

Profiling the diets of Classic Maya communities living in Southeastern Petén through stable isotope analysis

Australian cave discovery shows grass burned for magic, healing, cursing for 25,000 years

 

Perfectly preserved ‘phytolith’ plant crystals reveal that indigenous Australians took grasses into cave for ritual burning since last Ice Age

Peer-Reviewed Publication

Frontiers

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

GunaiKurnai Elder Uncle Russell Mullett at the cave entrance of Cloggs Cave

view more 

Credit: Jess Shapiro, courtesy of GunaiKurnai Land and Waters Corporation

The GunaiKurnai, an Australian Aboriginal nation, are the acknowledged traditional custodians of Gippsland and the southern Victorian Alps. Within their territory are caves, known from 19th-century ethnographic reports and oral traditions to have been the setting for magic, healing, and cursing rituals by powerful learned women and men called ‘mulla-mullung’, as well as by other spiritual practitioners. Archaeologists have shown that people have been visiting one of these caves, Cloggs Cave, for such activities over the past 25,000 years.

“Here we show that the Old Ancestors selected whole grasses from the wider landscape and carried them into Cloggs Cave to spread out in thin layers and burn. Over time, sediments covered these burnt layers, preserving each layer on top of another over thousands of years,” said Dr Elle Grono, a postdoctoral researcher at the Australian National University and the corresponding author of a new study published in Frontiers in Environmental Archaeology.

Phytoliths and a standing stone

Grono and colleagues from Australia, France, and New Zealand studied the phytoliths – microscopic silica bodies from plant tissues – recovered from buried deposits in Cloggs Cave. The study was part of archaeological excavations undertaken in 2019 and 2020 that aimed to understand how people gathered plants for use inside the cave in the past. These excavations had been requested by the GunaiKurnai Land and Waters Corporation, with representatives of the GunaiKurnai community taking part in the study design, fieldwork, interpretations, and dissemination of the results.

“Unlike pollen, which is dispersed by wind or insects, phytoliths mostly accumulate at the spot where a plant decays. No plants grow inside the cave due to a lack of light, so the phytoliths must have been carried in by people or by animals such as possums on their fur or through their scats,” explained Grono. “We focused on half-burnt phytoliths from ashy layers, which can only have been brought in by people, as unburnt ones might have arrived through either means.”

The scientists used microscopy to assign taxonomic groups to thousands of phytoliths from two pits, respectively 1.5 m and 2.3 m deep. The top strata of these pits consisted of 73 thin ashy layers laid down by people between approximately 4,400 and 1,600 years ago, as calculated by optically stimulated luminescence and carbon dating via accelerator mass spectrometry. Within those ashy layers, they unexpectedly uncovered a 28-cm-high standing stone, subsequently shown to have been erected in the cave by Old Ancestors for ritual purposes around 2,000 years ago.

Grasses preferred

In total, the authors found 29 different types of phytoliths from a range of plant groups including grasses, herbs, and woody plants. They were mostly well preserved, with even the most delicate silica structures such as hair cells surviving pristine. The most abundant (up to 97%) were from grasses, both from the subfamily Pooideae which prefer temperate or cool climates, and from Panicoideae which mostly grow under warm and humid conditions. Phytoliths from the Chloridoideae family, drought-resistant grasses that grow well in warm, dry arid environments were less common, while those from woody plants and herbs were rare.

The Old Ancestors were very selective as to which types of plants they brought into the cave. They avoided diverse species from the riparian forest and open woodland found in the vicinity of Cloggs Cave before European settlement, and instead targeted grasses that would have been available a short distance away from the cave entrance.

“The phytoliths found at Cloggs Cave were from different parts of grass plants such as stems, leaves, flowers and roots, indicating that whole grasses were brought in, including the inedible parts,” said Grono.

Overall, nearly a fifth – up to 18% – of the phytoliths were burnt or melted. Their presence throughout the dated deposits implied that people had brought plants into the cave and burnt them there over the entire time-span of the past 25,000 years.

Professor Bruno David from Monash University who co-led the excavations with GunaiKurnai Land and Waters Corporation concludes that “their burning is consistent with GunaiKurnai traditional practices of using ash to perform magic and rituals, and also to track the footsteps of anyone coming in, including spirit-Beings. Other macro-botanical evidence such as fat-smeared trimmed wooden sticks from Casuarina trees were also found in deeper and older deposits, indicating that other kinds of rituals using woody plants were also performed.”

---

Journal

Frontiers in Environmental Archaeology

DOI

10.3389/fearc.2026.1871928 

Black Sea waters reshaped Eastern Mediterranean circulation 11,000 years ago

A new study led by the University of Barcelona reveals that freshwater exported from the Black Sea to the Aegean Sea triggered major environmental changes across the Eastern Mediterranean

Peer-Reviewed Publication

University of Barcelona

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

A new study led by the University of Barcelona reveals that freshwater exported from the Black Sea to the Aegean Sea triggered major environmental changes across the Eastern Mediterranean.

view more 

Credit: Communications Earth & Environment

An international team of researchers led by the University of Barcelona, in collaboration with the University of the Aegean and the Hellenic Centre for Marine Research, has uncovered evidence showing that a massive outflow of low-salinity water from the Black Sea into the Aegean Sea during the Early Holocene (approximately 11,000-6,000 years ago) played a much more important role in shaping the Eastern Mediterranean than previously thought.

The study, published in the Nature Portfolio journal Communications Earth & Environment, demonstrates that freshwater exported from the Black Sea enhanced surface-water stratification in the Aegean Sea, suppressing the formation of deep waters and contributing to the development of the so-called Sapropel 1, a widespread organic-rich sediment layer deposited across the Eastern Mediterranean during the Early Holocene.

The findings extend beyond the Eastern Mediterranean’s past. By demonstrating how large freshwater inputs can disrupt deep-water formation and reorganize marine circulation, the study offers valuable insights into the links between climate, hydrology and ocean circulation during warm periods, helping scientists better understand the potential consequences of future climate change.

The Black Sea: More important than previously thought

For decades, scientists have largely attributed the formation of Sapropel 1 to increased freshwater input from North African rivers and enhanced precipitation over the northern Mediterranean region. These processes were thought to reduce deep-water formation and promote conditions favourable for the accumulation of organic-rich sediments on the seafloor. The new findings challenge this long-standing view by identifying the Black Sea as a major and previously underestimated driver of these environmental changes.

The results reveal that the combination of intensified meltwater input and increased precipitation across the vast Black Sea drainage basin during the Early Holocene strengthened the export of low-salinity water through the Dardanelles Strait. This freshwater pulse triggered a major reorganization of water masses in the northern and central Aegean Sea, increasing stratification of the water column and reducing the formation of deep waters.

“Our findings show that the formation of Sapropel 1 cannot be explained solely by changes in North African river discharge and regional precipitation,” explains Dimitris Evangelinos, lead author of the study and member of the Marine Geosciences Research Group (Gmar) at the UB’s Faculty of Earth Sciences.

“The Black Sea acted as a powerful source of freshwater that fundamentally altered ocean circulation in the Aegean Sea and played a decisive role in the environmental transformation of the Eastern Mediterranean”, explains Evangelinos, from the UB’s Department of Earth and Ocean Dynamics.

More than 42,000 years of environmental history

​​​To reach these conclusions, the researchers analysed a marine sediment core recovered from the central Aegean Sea, close to key deep-water formation areas in the northern Aegean. The sediment archive preserves more than 42,000 years of environmental history. The study relied on a suite of advanced analyses carried out in state-of-the-art laboratories at the UB and its Science and Technology Centres (CCiTUB). By combining multiple innovative approaches, including grain-size analysis, X-ray fluorescence scanning, radiogenic isotopes and stable isotope geochemistry, the team reconstructed past changes in ocean circulation and distinguish the influence of Black Sea outflow from other climatic and hydrological processes.

This research was supported by the MORIA project (2023-2027), and received funding from the the State Research Agency of the Ministry of Science, Innovation and Universities, the European Research Council Consolidator Grant and the NextGenerationEU programme, among other institutions.

 

---

Journal

Communications Earth & Environment

DOI

10.1038/s43247-026-03730-6