Evolutionary Insights by Anthropology.net

The shift from a hunter-gatherer existence to an agrarian lifestyle stands as one of the most profound transformations in human history. Traditionally, scholars have attributed this Neolithic transition to external factors like climatic shifts or the allure of fertile lands. However, recent research challenges this narrative, emphasizing the pivotal role of human interactions and demographic dynamics in this monumental change.​

Human Dynamics Over Environmental Determinism

A study published in Proceedings of the National Academy of Sciences introduces a fresh perspective on the Neolithic transition. Researchers from institutions including the University of Bath and the Max Planck Institute for Evolutionary Anthropology have developed a mathematical model that underscores the significance of human demographic interactions over environmental factors. This model suggests that the interplay between migrating early farmers and indigenous hunter-gatherers—characterized by competition, cooperation, and cultural exchange—was instrumental in the spread of agricultural practices.​

Modeling Interactions: Insights from Predator-Prey Dynamics

Drawing inspiration from ecological models that describe predator-prey relationships, the researchers examined how early farmers and hunter-gatherers might have influenced each other's population dynamics. Their findings indicate that the expansion of farming communities was not merely a passive diffusion but involved active migration and interaction with local populations. These interactions led to varying population growth and mortality rates, ultimately shaping the demographic landscape of the regions undergoing this transition.​

Dr. Javier Rivas from the University of Bath remarks,​

"Our study provides a new perspective on prehistoric societies. By statistically fitting our theoretical predator-prey model to observed population dynamics inferred from radiocarbon dates, we explored how population growth shaped history and uncovered interesting patterns—such as how the spread of farming, whether by land or sea, influenced interactions between different groups. More importantly, our model also highlights the role of migration and cultural mixing in the rise of farming."​

Genetic Evidence of Farmer and Hunter-Gatherer Interactions

Complementary genetic studies further illuminate the complexity of these interactions. Research indicates that early European farmers did not entirely displace local hunter-gatherers. Instead, there was a prolonged period of coexistence and genetic admixture. For instance, a study focusing on prehistoric individuals from France and Germany revealed significant levels of hunter-gatherer ancestry in early farming communities, suggesting continuous contact and integration between these groups over centuries.

Population Growth: The Agricultural Catalyst

The advent of agriculture undeniably spurred significant demographic changes. Genetic analyses have shown that regions adopting farming experienced rapid population expansions. In Europe, Southeast Asia, and sub-Saharan Africa, the timing of these demographic booms aligns closely with the origins of agriculture, underscoring the transformative impact of farming on human societies. ​

Conclusion

These insights compel us to reconsider the narrative of the Neolithic transition. Rather than being a passive response to environmental opportunities, the shift to agriculture appears to be deeply rooted in human agency, characterized by migration, interaction, and cultural exchange. Understanding these dynamics not only enriches our comprehension of human history but also highlights the intricate web of relationships that have shaped our collective past.

Further Reading

For those interested in delving deeper into this topic, consider the following studies:

* Lipson, M., Szécsényi-Nagy, A., Mallick, S., et al. (2017). Parallel palaeogenomic transects reveal complex genetic history of early European farmers. Nature. ​

* Rivollat, M., Jeong, C., Schiffels, S., et al. (2020). Ancient genome-wide DNA from France highlights the complexity of interactions between Mesolithic hunter-gatherers and Neolithic farmers. Science Advances, 6(22), eaaz5344. ​

* Gignoux, C. R., Henn, B. M., & Mountain, J. L. (2011). Rapid, global demographic expansions after the origins of agriculture. Proceedings of the National Academy of Sciences, 108(15), 6044–6049. ​

These works provide comprehensive insights into the genetic and demographic shifts accompanying the dawn of agriculture.

This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit www.anthropology.net/subscribe

The human brain stands apart in the animal kingdom, not just in sheer size but in its remarkable cognitive abilities. For decades, researchers have sought to understand what genetic changes fueled the expansion of our neocortex, the region responsible for higher-order thinking, reasoning, and language. A recent study published in Science Advances by Nesil Eşiyok and colleagues sheds light on this question, identifying a crucial genetic duo—NBPF14 and NOTCH2NLB—that orchestrates the abundance of neural progenitor cells, a key factor in the evolutionary enlargement of the human brain.

The Role of NBPF14 and NOTCH2NLB

At the heart of this discovery is the interplay between two genes that are uniquely human. The study demonstrates that NBPF14 and NOTCH2NLB function in tandem to regulate the proliferation and transformation of neural progenitor cells, the building blocks of the developing neocortex.

* NBPF14 stimulates the multiplication of these progenitor cells, ensuring an ample supply during brain development.

* NOTCH2NLB directs these progenitor cells toward a more specialized type, which eventually matures into the neurons that compose our brain’s intricate networks.

This genetic interaction sets humans apart from other primates, providing a biological explanation for why our neocortex is uniquely large and complex.

Experimental Evidence: A Multi-Faceted Approach

To uncover the role of these genes, researchers combined multiple experimental approaches, including:

* Mouse Models: Introducing human versions of these genes into mice resulted in an increase in neural progenitor cells, suggesting a direct link between gene function and brain expansion.

* Chimpanzee Brain Organoids: By cultivating miniature brain-like structures from chimpanzee stem cells, the researchers observed how the absence of these human-specific genes limited neural progenitor proliferation.

* Human Brain Tissue Analysis: Further supporting their findings, the study examined human fetal brain tissue to confirm the expression patterns of NBPF14 and NOTCH2NLB in early brain development.

"The remarkable feature of our study is that results from both animal models and alternative methods complement each other well and mutually confirm their findings," explains Michael Heide, the study’s lead researcher. "This not only underscores the significance of our work but also highlights the potential for reducing reliance on animal models by refining alternative methods."

Evolutionary and Medical Implications

Understanding the genetic underpinnings of human brain expansion has profound implications beyond evolutionary biology. These insights may help illuminate the origins of neurodevelopmental disorders such as microcephaly, in which brain size is significantly reduced due to disruptions in progenitor cell proliferation.

"Our findings deepen the fundamental understanding of brain development and provide new insights into the evolutionary origins of our large brain," says Nesil Eşiyok, first author of the study. "In the long term, they could contribute to the development of therapeutic approaches for malformations of the brain."

The Future of Human Brain Evolution Research

This study adds another piece to the puzzle of human brain evolution, but many questions remain. How did these genes originate and become unique to humans? What other genetic or environmental factors contributed to the increase in brain size over millions of years? Future research will continue to probe these mysteries, combining genetic analysis with fossil and archaeological evidence to paint a more complete picture of our evolutionary past.

With each discovery, the story of human brain evolution becomes clearer, offering a deeper appreciation for the genetic symphony that shaped our species’ most defining trait—our intelligence.

This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit www.anthropology.net/subscribe

The human pelvis is a structural keystone—shaping movement, birth, and even evolutionary trajectories. Now, a fossilized pelvis found in South Africa’s Drimolen Main Quarry (DMQ) is providing rare insights into the anatomy and biomechanics of early hominins. Dating to approximately two million years ago, the partial pelvis, designated DNH 43, raises new questions about how early relatives of Homo sapiens walked, gave birth, and adapted to their environments.

The Significance of DNH 43

Fossilized hominin pelvises are exceptionally rare, making DNH 43 a crucial find. Recovered from DMQ—a site known for yielding both Paranthropus robustus and some of the earliest remains of Homo erectus—this specimen includes the sacrum and portions of the right os coxae. While past studies linked the fossil’s morphology to Australopithecus and Paranthropus, a new in-depth analysis offers a more comprehensive comparison across hominin species.

The research team reconstructed the pelvis using digital modeling and analyzed its shape relative to an expanded dataset of fossil specimens. Their findings highlight a mix of primitive and derived traits, suggesting that Paranthropus robustus—a robust, small-brained hominin—may have had a more complex locomotor and obstetric anatomy than previously assumed.

A Unique Mix of Features

DNH 43 exhibits several characteristics linking it to Australopithecus and Paranthropus, including a small overall size, relatively narrow sacroiliac articulation, and a moderately wide tuberoacetabular sulcus. However, one of the most surprising findings was its pelvic incidence—the angle at which the sacrum orients the upper body over the pelvis.

“The orientation of the sacrum in DNH 43 is strikingly similar to that of modern humans,” the researchers note. “This challenges some long-standing assumptions about early hominin posture and locomotion.”

The study also found that while the overall structure of the pelvis retains a primitive, gracile morphology, it features a broad birth canal, suggesting that Paranthropus robustus may have had a different childbirth process than previously hypothesized.

What This Means for Hominin Evolution

The findings have significant implications for understanding locomotion and reproduction in early hominins. While Paranthropus robustus has long been thought to have relied on a more ape-like, rigid gait, the morphology of DNH 43 suggests a more efficient bipedal posture.

The breadth of the pelvic inlet and biacetabular dimensions of DNH 43 are also noteworthy. Compared to other hominin specimens, these proportions suggest that its species might have had a more adaptable approach to childbirth. Unlike modern humans, who experience a complex rotational birth mechanism due to the conflicting demands of a large brain and a narrow pelvis, Paranthropus robustus may have given birth through a more straightforward, non-rotational process, similar to what has been inferred for Australopithecus.

Future Directions

Despite these insights, much remains uncertain. While DNH 43 is currently attributed to Paranthropus robustus, its similarities with Australopithecus and even early Homo specimens underscore the need for further research on postcranial variation in early hominins. Future discoveries may help clarify whether traits observed in DNH 43 were unique to Paranthropus robustus or shared across other hominin lineages.

“Our findings emphasize the importance of postcranial remains in reconstructing the evolutionary history of early hominins,” the researchers explain. “The more we learn about their anatomy, the better we can understand how different species moved, survived, and ultimately gave rise to our own lineage.”

As paleoanthropologists continue to uncover fossils in the Cradle of Humankind, specimens like DNH 43 will remain crucial in refining our understanding of early human evolution. This pelvis may not answer all questions, but it brings us one step closer to piecing together the intricate puzzle of hominin adaptation.

This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit www.anthropology.net/subscribe

The narrative of human technological advancement has long positioned metallurgy as a hallmark of settled agricultural societies. However, recent findings from the Gre Fılla site in southeastern Turkey suggest that the roots of metalworking may extend deeper into our hunter-gatherer past than previously understood.​

The Gre Fılla Site: A Window into Prehistoric Innovation

Nestled in the upper Tigris Valley, Gre Fılla has been under excavation since 2018. This site, spanning from the Pre-Pottery Neolithic (PPN) to the Pottery Neolithic periods, offers a rare glimpse into the lives of Anatolia's last hunter-gatherers. Among the architectural remnants and everyday artifacts, researchers have uncovered compelling evidence of early copper use and production.​

Evidence of Early Metallurgical Practices

In the layers corresponding to the Pre-Pottery Neolithic B (PPNB) period, several notable discoveries have been made:​

* Copper Artifacts: Items such as a bar-shaped copper object and various unworked lumps indicate familiarity with the metal.

* Vitrified Materials: Fragments exhibiting signs of exposure to high temperatures, some containing embedded copper droplets, suggest experimental smelting or annealing processes.​

These findings challenge the traditional timeline, which places the advent of copper metallurgy in the Chalcolithic period, around 4000 BCE. The evidence from Gre Fılla pushes this date back by several millennia, indicating that hunter-gatherer communities were engaging with complex pyrotechnology as early as 7000 BCE.​

Analyzing the Artifacts

To understand the nature of these early metallurgical activities, a suite of analytical techniques was employed:​

* X-ray Fluorescence Spectroscopy (pXRF): Used to determine the elemental composition of the artifacts.​

* Flame Atomic Absorption Spectroscopy (FAAS): Applied for precise quantification of metal concentrations.​

* X-ray Diffraction (XRD): Utilized to identify mineralogical phases present in the vitrified materials.​

One particularly intriguing artifact, a copper bar-shaped object, underwent lead isotope analysis. The results indicated that the metal's source was not the nearby Ergani mines but rather distant regions near the Black Sea, such as Trabzon or Artvin. This suggests the existence of extensive exchange networks during this period, highlighting a level of socio-economic complexity not typically attributed to hunter-gatherer groups.​

Implications for the History of Metallurgy

The discoveries at Gre Fılla necessitate a reevaluation of the origins of metallurgy. The transition from the Neolithic to the Chalcolithic may have been more gradual and regionally variable than previously thought, involving phases of experimentation and innovation within hunter-gatherer communities.​

Furthermore, these findings underscore the importance of localized developments in technological advancement. Rather than a singular origin point, metallurgy may have emerged independently in various regions, influenced by local resources, knowledge systems, and cultural practices.​

Conclusion

The evidence from Gre Fılla paints a more nuanced picture of our prehistoric ancestors, showcasing their ingenuity and adaptability. As excavations continue and analytical techniques advance, it is likely that our understanding of early technological innovations will continue to evolve, shedding new light on the complex tapestry of human history.​

Related Research

For those interested in further exploring early metallurgical practices and their implications, the following studies provide valuable insights:​

* "Elemental Analysis of Pre-Pottery Neolithic B Copper Finds from Gre Fılla": This study offers a detailed chemical analysis of copper artifacts from Gre Fılla, providing insights into early metallurgical techniques.​

* "Early Copper Production by the Last Hunter-Gatherers": This research presents evidence of advanced copper production techniques during the PPNB period at Gre Fılla, contributing to our understanding of early human engagement with metallurgy.

This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit www.anthropology.net/subscribe

Neanderthals are often recognized for their distinct facial features—large, forward-projecting midfaces, prominent brow ridges, and wide nasal openings. In contrast, modern humans have relatively smaller, flatter faces with retracted midfaces and more delicate bone structures. For decades, researchers have debated the evolutionary forces behind these differences.

* Was Neanderthal facial anatomy an adaptation to cold climates?

* A byproduct of powerful biting forces?

* Or was it simply the result of genetic drift?

A recent study published in the Journal of Human Evolution examines these questions from a new angle—by tracking how facial growth unfolds from infancy to adulthood in Neanderthals, modern humans (Homo sapiens), and chimpanzees (Pan troglodytes verus). Using a combination of 3D geometric morphometrics and microscopic bone analysis, the study explores how these species differ not just in their final adult form, but in the developmental pathways that get them there.

How Faces Grow: A Comparative Approach

At birth, Neanderthals already have larger midfaces than modern humans. That gap widens over time, but not in the way many might expect. Instead of growing at a steady rate like humans, Neanderthal midfaces expand dramatically during childhood and adolescence. By contrast, modern human faces reach their adult size much earlier—often by adolescence—before slowing or stopping entirely.

To track these changes, researchers compared skulls from 128 modern humans, 13 Neanderthals, and 33 chimpanzees. Using 3D surface scans and microscopic bone modeling, they analyzed how each species' maxilla—the central bone of the midface—changed shape and size throughout life.

The results show that Neanderthals exhibit prolonged growth compared to modern humans, which contributes to their robust, projecting facial structure. Modern humans, on the other hand, experience earlier cessation of facial growth, contributing to their smaller, flatter midfaces. Chimpanzees, though distinct from both groups, exhibit a growth trajectory more similar to Neanderthals, further supporting the idea that modern human facial development is an evolutionary outlier.

"The midfaces of Neanderthals are on average already larger at birth than those of modern humans and continue growing for a longer period, contributing to their distinctive facial projection," explains lead author Alexandra Schuh of the Max Planck Institute for Evolutionary Anthropology.

Bone Remodeling and Facial Shape

What causes these growth differences? At a microscopic level, bones grow and change shape through a process called remodeling, which involves both bone formation and resorption (the breakdown of bone tissue). The study found that modern humans have higher levels of bone resorption in the midface than Neanderthals, leading to a retracted, flatter facial structure.

Neanderthals, by contrast, show greater bone formation in the nasal and infraorbital regions, which helps maintain their large, projecting midfaces throughout development. In other words, the way bone is added or removed during growth plays a major role in determining the final shape of the face.

"Our findings highlight how the balance between bone formation and resorption shapes the distinct facial morphologies of Neanderthals and modern humans," says co-author Philipp Gunz.

Interestingly, these patterns differ from those seen in chimpanzees. While Neanderthals and modern humans share some similarities in their facial remodeling processes, chimpanzees exhibit distinct bone growth patterns, particularly in the development of their prominent canine region. This suggests that the unique growth trajectory of modern humans is not just an extension of our evolutionary past but a departure from it.

Why Do These Differences Matter?

The distinct facial growth patterns observed in modern humans may be linked to broader evolutionary changes, including shifts in diet, social structure, and even cognition. Some researchers argue that the reduction in facial size and projection in Homo sapiens is connected to changes in dietary habits—particularly the advent of cooking and tool use, which reduced the need for powerful biting and chewing.

Others propose that these facial changes are part of a broader trend toward "self-domestication" in humans—a process in which social selection favors individuals with more juvenile, less aggressive facial traits.

"Facial gracilization in modern humans may be linked to behavioral changes, such as increased social cooperation and reduced aggression," says co-author Sarah Freidline.

Additionally, differences in facial growth could have played a role in speech and communication. Some researchers suggest that the retraction of the modern human midface may have altered vocal tract anatomy, contributing to our ability to produce a wider range of speech sounds.

Neanderthals: A Different Developmental Path

While Neanderthals and modern humans share a common ancestor, their distinct growth trajectories suggest that they evolved along different developmental paths. The prolonged facial growth in Neanderthals may have been an adaptation to high-energy lifestyles, cold climates, or unique social behaviors.

By contrast, the early cessation of facial growth in modern humans may have set the stage for the unique physical and cognitive traits that define our species today.

Final Thoughts

This study sheds light on the fundamental differences in how Neanderthal and modern human faces grow and develop. Rather than focusing solely on their adult differences, it highlights the underlying developmental processes that shaped their evolutionary paths.

Understanding these growth patterns not only helps explain why Neanderthals looked the way they did but also offers insight into the evolutionary forces that shaped our own species. And while Neanderthals may be gone, the echoes of their biology live on in the DNA of modern humans—reminding us that our evolutionary story is still being written.

Related Research

* Neanderthal Facial Growth and Adaptation

* Bastir, M., & Rosas, A. (2016). Craniofacial levels and the morphological maturation of the human skull. Journal of Anatomy, 228(5), 784-797. https://doi.org/10.1111/joa.12455

* The Role of Diet in Human Facial Evolution

* Lieberman, D. E. (2008). Speculations about the selective basis for modern human cranial form. Evolutionary Anthropology, 17(1), 55-68. https://doi.org/10.1002/evan.20169

* Self-Domestication and Facial Gracilization

* Cieri, R. L., et al. (2014). Craniofacial feminization in modern humans: Self-domestication or sexual selection? Current Anthropology, 55(4), 419-443. https://doi.org/10.1086/677209

* The Impact of Growth on Craniofacial Form

* Ponce de León, M. S., & Zollikofer, C. P. (2001). Neanderthal cranial ontogeny and its implications for late hominid diversity. Nature, 412(6846), 534-538. https://doi.org/10.1038/35087578

This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit www.anthropology.net/subscribe

The early human settlement of South America stands as one of the last great migrations in human history, yet the environmental conditions that shaped this journey remain debated. New research by Lorena Becerra-Valdivia, published in Nature Communications, suggests that humans did not simply follow stable climates but adapted to fluctuating conditions, sometimes settling in areas experiencing severe cold. Using Bayesian chronological modeling and data from over 150 archaeological sites, the study examines how two major climatic events—the Antarctic Cold Reversal (ACR) and the Younger Dryas (YD)—influenced early human dispersal across the continent.

The Antarctic Cold Reversal and the First Settlements

When early humans arrived in South America, they encountered a continent undergoing dramatic climate shifts. Around 14,700 to 13,000 years ago, the Southern Hemisphere experienced the Antarctic Cold Reversal, a period of cooling that reversed the warming trend seen in the Northern Hemisphere. Instead of deterring settlement, this cold phase appears to coincide with some of the earliest human activity in the region.

According to Becerra-Valdivia's study, sites in the southern Andes and Patagonia show evidence of human occupation before or during this cold phase. This suggests that early settlers may have developed cultural adaptations that allowed them to survive in colder conditions.

"The cultural timeline does not indicate that cold conditions were a barrier to human expansion," the study notes. "Rather, the earliest known human activity aligns with regions most affected by cooling, particularly in high-altitude and southernmost areas."

The findings challenge earlier assumptions that humans would have avoided these harsh environments. Instead, their ability to endure may have been aided by cumulative knowledge, allowing them to exploit diverse ecological niches despite temperature fluctuations.

The Younger Dryas and Expansion Across the Continent

Following the Antarctic Cold Reversal, the Younger Dryas—a sharp cooling event that lasted from approximately 12,900 to 11,700 years ago—brought further environmental instability. This event, however, appears to have played a different role in human settlement. The study suggests that widespread occupation of South America became more pronounced after the Younger Dryas, as conditions stabilized.

A key pattern observed in the data is a west-to-east dispersal trend. Early occupation appears concentrated in the western Andes, with later settlements spreading toward the lowlands and eastern regions.

"The Andes and the Pacific Coast likely served as primary routes for early human dispersal," Becerra-Valdivia explains. "Evidence suggests a later expansion toward interior regions such as the Paraguay-Paraná Lowlands."

This supports genetic studies indicating that the Andes played a crucial role in early South American population movements. While lowland rainforests and humid environments likely presented challenges for early settlers, the western highlands may have offered a more viable pathway for migration.

Rethinking Climate and Human Adaptation

The study also touches on a long-standing debate: were humans responsible for the extinction of South America's megafauna, or did climate play the dominant role? The archaeological evidence does not establish a clear causal link between human activity and megafaunal decline. Instead, the data suggest that hunting and scavenging of large animals, such as giant sloths and mastodons, began well before their extinction.

"The timing of megafaunal exploitation by humans does not directly align with their extinction patterns," the study states. "While human hunting may have contributed to population declines, the role of climate shifts cannot be overlooked."

This contrasts with theories that place humans as the primary drivers of megafaunal extinctions. Instead, the study emphasizes the need for more refined models that integrate archaeological, genetic, and environmental data.

Gaps in the Archaeological Record

Despite these insights, the research also highlights major gaps in the archaeological and chronometric record. Some regions, such as the Amazon and Orinoco Lowlands, are significantly underrepresented in radiocarbon dating efforts. The study calls for more systematic dating of stratified sites and improved documentation of cultural sequences.

"A more comprehensive dataset is needed to refine the cultural timeline," the study suggests. "Current gaps limit our ability to fully understand the pace and nature of early human settlement in South America."

Addressing these issues could provide a clearer picture of how humans adapted to diverse environments, from glaciated mountain ranges to humid tropical forests.

Conclusion

Rather than being driven solely by climate, early human settlement in South America appears to have been shaped by a combination of environmental shifts and cultural adaptation. The ability to inhabit regions experiencing severe cold suggests a level of resilience that may have been underestimated. As more data emerge, the story of the first South Americans continues to evolve, offering new perspectives on how humans navigated one of the most complex migrations in history.

Related Research and Citations

If you're interested in further exploring the intersection of climate and early human migration, the following studies may be of interest:

* Prates, L., & Pérez, S. I. (2021). "Late Pleistocene South American megafaunal extinctions associated with rise of Fishtail points and human population." Nature Communications, 12, 2175. https://doi.org/10.1038/s41467-021-22454-2

* Waters, M. R., & Stafford, T. W. (2007). "Redefining the age of Clovis: implications for the peopling of the Americas." Science, 315(5815), 1122-1126. https://doi.org/10.1126/science.1137166

* Moreno-Mayar, J. V., et al. (2018). "Early human dispersals within the Americas." Science, 362(6419), eaav2621. https://doi.org/10.1126/science.aav2621

These studies provide additional insights into the timing of human migration into the Americas and the ecological challenges early settlers faced.

This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit www.anthropology.net/subscribe

Archaeology often deals with what remains—the bones, the stone tools, the charred remnants of ancient hearths. But in the upland regions of Warner Valley, Oregon, a different kind of evidence is telling the story of early human diets: microscopic starch granules trapped in the cracks of bedrock metates. These stone grinding surfaces, found alongside rock art panels and other cultural features, are yielding the first direct evidence of plant processing in this landscape.

A study published in American Antiquity analyzed starch residues from 58 bedrock metates and identified granules from biscuitroot (Lomatium spp.), a geophyte that has been an important food source for Indigenous communities in the region for thousands of years​.

A Closer Look at the Bedrock Metates

Unlike portable grinding stones, bedrock metates are stationary features—shallow depressions worn into rock surfaces through repeated use. While their presence at archaeological sites suggests food processing activities, confirming what they were used for has been difficult. The study authors, led by archaeobotanist Stefania Wilks, hypothesized that plant starches might have been preserved deep in the stone’s crevices, protected from erosion and weathering.

To test this, researchers sampled metates from three rock art sites in Warner Valley: Corral Lake, Barry Spring, and Long Lake. They used a two-step extraction process—first scrubbing the surface of the metates and then applying a chemical deflocculant to dislodge starch granules trapped in microscopic crevices.

"It was critical to distinguish between surface contamination and deeply embedded residues," Wilks explained. "By comparing the results, we could confirm that these starches were not recent additions but rather remnants of ancient plant processing."

Biscuitroot and the Role of Geophytes in Early Diets

The analysis identified starch granules from a range of plants, but Lomatium spp. stood out. The plant, commonly known as biscuitroot, is a member of the carrot family (Apiaceae), and its starchy taproots have long been valued for their nutritional properties.

"Geophytes like biscuitroot are an incredibly resilient food source," Wilks said. "They store carbohydrates underground, making them available even in dry or cold seasons. This would have been crucial for past hunter-gatherer groups in the northern Great Basin."

Ethnographic accounts describe Indigenous groups harvesting Lomatium with digging sticks in the spring, pounding the roots into cakes for long-term storage. The starch granules extracted from the metates closely matched those of modern Lomatium, providing direct evidence that these plants were ground and processed on-site.

Ancient Kitchens in the Landscape

The study also suggests that these rock art sites were not just places of symbolic expression but were directly linked to subsistence activities. The presence of grinding surfaces near large stands of edible plants supports the idea that people returned to these locations seasonally, taking advantage of the natural abundance.

Interestingly, the researchers found evidence that some metates had been reused over long periods. Patina analysis showed that some surfaces bore signs of older grinding activity, with newer use-wear overlaid on top.

"This pattern indicates that these places held significance over generations," Wilks noted. "People were returning to the same spots, likely because of their proximity to reliable food sources."

Revising Assumptions About Early Foraging Strategies

The discovery challenges long-standing assumptions that upland environments were primarily used for hunting rather than plant processing. Archaeologists have long associated high-elevation sites with seasonal game tracking, but the presence of grinding tools and starch granules suggests a more complex picture.

"As archaeologists, we've tended to focus on hunting as the primary activity at these sites," Wilks said. "But this evidence forces us to think more broadly about what people were doing in these landscapes. They weren’t just chasing game; they were processing plant foods in ways that left lasting traces in the stone."

The findings also add to a growing body of research demonstrating that geophytes were a staple in early North American diets. Previous studies have identified geophyte starch in sites dating back to the Late Pleistocene and Early Holocene, reinforcing the idea that plant foods played a central role in subsistence strategies​.

A New Tool for Studying Ancient Diets

The success of starch analysis in this study highlights the potential of the method for investigating ancient diets in other open-air settings. While charred seeds and pollen can sometimes provide clues about plant use, starch granules offer a more direct link to food processing.

"This approach is especially valuable in places where organic remains don’t typically preserve well," Wilks said. "By looking at the microscopic residues left behind, we can reconstruct aspects of daily life that would otherwise be invisible in the archaeological record."

The research team hopes to expand their work to other regions, testing whether similar grinding features elsewhere in the Great Basin contain preserved plant residues.

"What we’re seeing here may be part of a much broader pattern," Wilks said. "These upland sites may have been essential food processing locations for thousands of years, and we’re just beginning to understand their role in the larger subsistence landscape."

Related Research

For those interested in further reading on starch analysis and geophyte use in early diets, here are some key studies:

* Louderback, L. A., & Pavlik, B. M. (2017). "Starch Granule Evidence for the Earliest Potato Use in North America." PNAS, 114(29), 7606–7610. https://doi.org/10.1073/pnas.1707710114

* Herzog, N. M., & Lawlor, A. T. (2016). "Reevaluating Diet and Technology in the Archaic Great Basin Using Starch Grain Assemblages from Hogup Cave, Utah." American Antiquity, 81(4), 664–681. https://doi.org/10.1017/S0002731600101027

* Henry, A. G. (2020). "Starch Granules as Markers of Diet and Behavior." In Handbook for the Analysis of Micro-Particles in Archaeological Samples. Springer. https://doi.org/10.1007/978-3-030-51103-2_5

This study provides a powerful reminder that even the smallest traces—microscopic starch granules—can reshape our understanding of human history.

This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit www.anthropology.net/subscribe

For decades, the story of modern human origins seemed relatively straightforward: Homo sapiens emerged in Africa roughly 300,000 years ago, evolving as a single, continuous lineage before expanding across the globe. But new research suggests that this narrative is missing an entire chapter.

A study published in Nature Genetics by Trevor Cousins, Aylwyn Scally, and Richard Durbin of the University of Cambridge proposes that modern humans did not descend from a single population, but rather from two deeply divergent ancestral groups. These two populations split approximately 1.5 million years ago and remained separate for over a million years before mixing again around 300,000 years ago. One of these groups contributed about 80% of modern human DNA, while the other—now vanished—left a genetic imprint making up the remaining 20%.

"Rather than a single lineage evolving smoothly over time, the evidence suggests a history of separation and recombination," says Cousins. "These groups were apart for a million years—longer than modern humans have been on the planet."

This discovery complicates the long-held assumption that our species emerged from a single, unbroken line of ancestors. It also raises new questions about which fossil hominins—such as Homo erectus and Homo heidelbergensis—might represent these lost populations.

A Hidden Population, a Vanished Legacy

What makes this finding particularly striking is that this ancient genetic mixing event is not just a curiosity of the distant past. It is present in every modern human population, across Africa, Europe, Asia, and the Americas.

Unlike the more familiar interbreeding episodes with Neanderthals and Denisovans—events that contributed only about 2% of the DNA in non-African populations—this deeper ancestral mixture accounts for ten times that amount. And yet, until now, it had remained invisible in our understanding of human evolution.

The researchers made this discovery not by analyzing ancient bones but by studying the DNA of living people. Using data from the 1000 Genomes Project, they applied a computational model called cobraa (Coalescence-Based Reconstruction of Ancestral Admixture), which allowed them to detect subtle genetic signals left by ancient populations. This approach circumvents the need for physical fossils, offering a way to reconstruct population history even when no bones or artifacts remain.

A Genetic Bottleneck and the Fate of Our Ancestors

One of the study’s most intriguing findings is that, immediately after the initial split 1.5 million years ago, one of the two populations went through a severe genetic bottleneck. This group shrank to a tiny size before slowly recovering. Over time, this population eventually gave rise to the majority of Homo sapiens ancestry, as well as to Neanderthals and Denisovans.

"This population bottleneck could be the result of an ecological crisis, a migration event, or simply chance," says Scally. "What’s remarkable is that despite its small size, this group ultimately shaped most of our genetic heritage."

The other group—whose genes now make up the remaining 20% of modern human DNA—appears to have remained larger but was eventually absorbed into the expanding Homo sapiens population.

Interestingly, the researchers found that genetic material from this secondary group tended to be located away from functionally important regions of the genome, suggesting that some of its DNA may not have been fully compatible with the majority genetic background. This pattern hints at a process called purifying selection, in which harmful mutations are gradually removed from a population over time.

Who Were These Lost Ancestors?

This discovery invites a crucial question: If these two populations remained separate for over a million years, what did they look like? Were they physically distinct, akin to separate species? And do they correspond to any known hominin fossils?

Fossil evidence suggests that Homo erectus was widespread across Africa and Eurasia throughout this period. Other species, such as Homo heidelbergensis, also inhabited Africa and Europe. Either of these groups—or even an as-yet-undiscovered lineage—could be the long-lost ancestors detected in this study.

"These populations were likely distinct in ways we don’t yet understand," says Durbin. "We may find fossils that match their genetic legacy, or we may already have them but lack the tools to identify their role in our ancestry."

If this ancient mixing event is confirmed through further research, it could reshape how we classify and think about human evolutionary history. Rather than a single lineage, our origins may have been more like a braided stream—separate currents that merged over time.

Rethinking Species Boundaries in Human Evolution

The idea that modern humans emerged from multiple ancestral populations aligns with a broader shift in how biologists think about evolution. Increasingly, researchers are finding that species do not always evolve in neat, separate branches but often exchange genes across long periods.

"What’s becoming clear is that species don’t evolve in isolation," Cousins explains. "Interbreeding and genetic exchange have likely played a role in the emergence of new species across the animal kingdom, not just in humans."

This study also suggests that similar events may have occurred in other species. The researchers applied their method to genetic data from bats, dolphins, chimpanzees, and gorillas, and found evidence of deep ancestral structure in some of these species as well.

What Comes Next?

With this new model of human origins, researchers now have a fresh set of questions to explore. What conditions allowed these populations to remain separate for so long? What finally brought them back together? Did their reunion contribute to the development of cognitive traits that define modern humans?

To refine these findings, scientists may turn to ancient DNA—if they can find it. Fossils from the crucial period around 300,000 years ago could hold traces of these lost ancestors, offering a direct genetic link to the populations detected in modern DNA.

"The fact that we can reconstruct events from hundreds of thousands or even millions of years ago, just by looking at DNA today, is astonishing," says Scally. "It tells us that our history is far richer and more complex than we ever imagined."

Conclusion

The story of human origins is still being written. As researchers develop new genetic tools and unearth new fossils, the narrative continues to shift. What this study makes clear is that Homo sapiens did not emerge from a single lineage but from the reunion of two deeply ancient populations—distant relatives who came together to form the species that would eventually inhabit every corner of the planet.

If this discovery holds, it could reshape how we define what it means to be human—not as the product of a linear march of progress, but as the outcome of ancient migrations, genetic exchanges, and lost populations that shaped our species in ways we are only beginning to understand.

Additional Related Research

* Skoglund, P., & Reich, D. (2020). Ancient DNA and the new science of the human past. Nature, 577, 645–656. https://doi.org/10.1038/s41586-019-1863-2

* Hublin, J. J., et al. (2017). "New fossils from Jebel Irhoud, Morocco and the pan-African origin of Homo sapiens." Nature, 546(7657), 289–292.

* DOI: 10.1038/nature22336

* This study presents evidence from Moroccan fossils suggesting that H. sapiens had a more widespread African origin than previously believed.

* Ragsdale, A. P., et al. (2023). "A weakly structured stem for human origins in Africa." Nature, 617(7962), 755–763.

* DOI: 10.1038/s41586-023-06184-w

* Supports deep population structure within Africa, indicating H. sapiens arose from multiple interconnected groups rather than a single lineage.

* Reich, D., et al. (2010). "Genetic history of an archaic hominin group from Denisova Cave in Siberia." Nature, 468(7327), 1053–1060.

* DOI: 10.1038/nature09710

* First genomic analysis of Denisovans, showing they contributed DNA to modern human populations.

* Terhorst, J., et al. (2017). "Robust and scalable inference of population history from hundreds of unphased whole genomes." Nature Genetics, 49(2), 303–309.

* DOI: 10.1038/ng.3748

* Develops computational tools to analyze population splits and admixture in human evolution.

This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit www.anthropology.net/subscribe

For decades, archaeologists have puzzled over one of humanity’s most crucial technological leaps—when and how early humans began making sharp stone tools. A new study proposes an unexpected answer: before hominins ever struck two rocks together, they may have been using naturally occurring sharp stones to butcher meat and process plants.

The research, published in Archaeometry, suggests that before the first intentional toolmakers, hominins may have relied on "naturaliths"—sharp rock fragments created by natural geological or biological processes. These early humans may have used these naturally occurring cutting tools long before they figured out how to produce them deliberately.

“The idea that early hominins just suddenly ‘invented’ knapping as a technological breakthrough doesn’t quite fit,” said Metin I. Eren, co-author of the study and an archaeologist at Kent State University. “There had to be an existing demand for sharp edges before anyone bothered to make them.”

Nature as the First Toolmaker

Stone tool production, or knapping, has long been considered one of the defining skills that set early humans apart from other primates. But Eren and his colleagues suggest that for hundreds of thousands of years before hominins learned to manufacture stone flakes, they simply collected and used ones already lying around. These naturaliths may have been produced in a variety of ways—rockfalls, erosion, wave action, glacial activity, and even trampling by large animals like elephants.

“In some places, nature makes hundreds or even thousands of these naturally sharp stones,” said co-author Michelle R. Bebber, an archaeologist at Kent State University. “Early hominins probably had access to an abundant supply of cutting tools without needing to make them.”

The researchers conducted fieldwork at multiple locations—including Kenya, South Africa, and Antarctica—to document how natural processes produce sharp-edged stones. They found that in many environments, these fragments were not rare at all. Some sites had thousands of sharp stone pieces scattered across the landscape, indistinguishable from early hominin-made tools.

The Missing Link Between Stone and Bone

The study argues that before the first knappers, hominins were already using sharp objects to process food. This likely started with bone flakes created during marrow extraction. Experiments with modern tools suggest that bone fragments can be used effectively to cut meat, but stone flakes are significantly sharper. If hominins were already using bone flakes, it’s not hard to imagine them picking up a naturalith and recognizing its advantage.

“Once you start using sharp-edged materials, you eventually start looking for ways to get more of them,” Eren said. “If you’re in an area with no naturaliths, you have a problem. That’s where knapping becomes useful.”

The researchers suggest that naturaliths served as a bridge between using bone flakes and intentionally striking rocks together to make sharp stone tools. This gradual shift—from opportunistic use to controlled production—may have set the stage for the technological explosion of the Oldowan industry around 2.6 million years ago.

Not a "Eureka!" Moment, But a Slow Discovery

The traditional view of early toolmaking suggests that one particularly clever hominin, perhaps while cracking a nut or smashing a bone, accidentally broke a rock and discovered the sharp edges it produced. But the new hypothesis suggests that knapping wasn’t an accident—it was an imitation of nature.

“Rather than being a sudden breakthrough, early knapping was likely an attempt to copy something that already existed,” said Eren. “Hominins weren’t inventing something new, they were figuring out how to make more of what they already used.”

This changes how archaeologists might interpret the earliest evidence of stone tool use. If early hominins were using naturaliths, then traces of tool use—cut marks on bones, for example—might predate the oldest known knapped tools. Future research will need to look for signs that early hominins collected and carried naturaliths before they mastered making their own.

Implications for Early Human Evolution

If early humans relied on naturaliths before learning to knap, it raises new questions about how our ancestors thought about technology. The ability to recognize and select useful objects in the environment is a key cognitive step in human evolution.

The findings also suggest that archaeologists should reconsider the definition of tool use in the fossil record. If a sharp stone was used by a hominin but not modified, does it still count as a tool?

“If naturaliths were being used extensively, then the history of tool use is likely much older than we think,” Bebber said. “And that means the origins of human technology are more complex than a single moment of invention.”

The Next Steps

To test the hypothesis, archaeologists will need to analyze ancient sites for patterns suggesting naturalith use. This could involve examining sites older than 3.3 million years—the age of the earliest known stone tools—to look for cut marks on bones that may have been made with unmodified rocks. Experimental archaeology could also help determine whether naturally occurring flakes are sharp enough to leave distinct traces that can be identified in the fossil record.

For now, the study challenges long-standing assumptions about the origins of tool use. Rather than a single discovery that launched the Stone Age, early hominins may have been cutting with sharp rocks for millennia before they ever struck two stones together with purpose.

Related Research:

* Harmand, S., Lewis, J. E., Feibel, C. S., et al. (2015). 3.3-million-year-old stone tools from Lomekwi 3, West Turkana, Kenya. Nature, 521(7552), 310-315. https://doi.org/10.1038/nature14464

* Plummer, T. W., Finestone, E. M., et al. (2023). Expanded geographic and taxonomic evidence for early butchery in the Oldowan. Science, 379(6628), 561-566. https://doi.org/10.1126/science.adf4234

* Key, A. J. M., Lycett, S. J. (2023). The evolution of hominin tool use: A functional perspective on early stone tools. Quaternary Science Reviews, 314, 107963. https://doi.org/10.1016/j.quascirev.2023.107963

This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit www.anthropology.net/subscribe

Some 4,000 years ago, the southeastern corner of the Iberian Peninsula was home to one of Europe’s first state-level societies: El Argar. From its fortified hilltop settlements, this Bronze Age power controlled vast territories, imposing its influence over neighboring groups through trade, warfare, and the steady flow of resources like metal, textiles, and ceramics.

But where exactly did El Argar end, and where did its less centralized neighbors begin? A new study has tackled this question by looking not at monumental architecture or elite burials, but at something far more humble: pottery.

By analyzing the production and circulation of ceramic vessels in what is now Murcia, Spain, researchers have been able to trace the shifting borders of El Argar’s influence. The findings suggest that this society maintained a firm grip over its core regions while engaging in complex, asymmetric relationships with surrounding groups in La Mancha and Valencia.

"The study of pottery production and distribution provides a unique perspective on how political and economic boundaries were established in the European Bronze Age," says Adrià Moreno Gil, a researcher at the Max Planck Institute for Social Anthropology and lead author of the study.

Mapping an Ancient Borderland

The study focuses on the Middle and Upper Segura River valley, a transitional zone between El Argar’s heartland and the less hierarchical communities to the north. Through a combination of archaeological surveys, petrographic analysis (studying the mineral composition of ceramics), and GIS-based spatial modeling, the research team identified distinct zones of pottery production and exchange.

At the southern end of the study area, close to El Argar’s core, ceramic production was highly standardized. The pottery here was made from clays rich in phyllosilicates and schist—raw materials found only in the Baetic mountain ranges, far to the south. The presence of this “Argaric-style” pottery suggests that these frontier settlements were firmly integrated into El Argar’s economic system.

Farther north, however, a different pattern emerged. In the borderlands of La Mancha and Valencia, ceramic production was far more localized, relying on clays and tempers that could be sourced nearby. These vessels were made in smaller batches, suggesting a domestic-scale production rather than a centrally organized industry.

"What we see is a stark contrast in economic organization," explains co-author Carla Garrido García from the Autonomous University of Barcelona. "While El Argar was mass-producing pottery and distributing it over long distances, its neighbors continued to rely on local, small-scale production."

This contrast was not just economic but political. The researchers argue that the distribution of pottery reflects the presence of a core-periphery system, where El Argar’s dominance gradually faded as one moved northward.

Clay as a Marker of Power

The movement of ceramics tells a story of political control, trade networks, and social hierarchy. The study found that El Argar’s signature pottery extended into some frontier settlements, but in a limited and highly selective manner.

In some cases, Argaric pottery appeared in substantial quantities, suggesting strong political ties to the core. But in other sites—particularly in the northernmost part of the study area—these ceramics were completely absent. Instead, local communities produced their own pottery, indicating a degree of autonomy from Argaric influence.

"The absence of Argaric pottery in certain areas suggests that El Argar’s political reach had limits," Moreno Gil notes. "These communities were not fully incorporated into the Argaric state but may have been in a loosely affiliated or even adversarial relationship with it."

A New Framework for Studying Bronze Age Borders

The study challenges older models that saw El Argar as a monolithic power uniformly expanding across southeastern Iberia. Instead, the ceramic evidence points to a more nuanced picture—one where political and economic boundaries were actively negotiated through trade, resource control, and regional alliances.

Perhaps most significantly, this research provides a methodological blueprint for identifying ancient borders elsewhere. The combination of ceramic petrography and spatial modeling could be applied to other prehistoric societies, from the Únětice culture of Central Europe to the palatial civilizations of Minoan Crete.

"Borders are rarely just lines on a map," says Garrido García. "They are zones of interaction, competition, and negotiation. And in archaeology, they are often written in clay."

As new discoveries continue to refine our understanding of ancient state formation, this study highlights the crucial role of everyday objects—like pottery—in shaping the political landscapes of the past. In the case of El Argar, its power may have been defined not just by its fortresses or weaponry, but by the simple ceramics that carried its influence across the Iberian Bronze Age world.

Additional Related Research

Here are some additional studies related to Bronze Age political boundaries, trade, and ceramic analysis:

* Kristiansen, K., & Larsson, T. B. (2005). The Rise of Bronze Age Society: Travels, Transmissions and Transformations. Cambridge University Press. DOI: 10.1017/CBO9780511614518

* Meller, H., Arz, H. W., Jung, R., & Risch, R. (Eds.). (2019). 2200 BC – A Climatic Breakdown as a Cause for the Collapse of the Old World? Landesamt für Denkmalpflege und Archäologie Sachsen-Anhalt. DOI: 10.11588/propylaeum.637

* Vandkilde, H. (2014). Breakthroughs and breakdowns: Exploring the long-term impact of the 3rd millennium BC in the European Bronze Age. In European Journal of Archaeology, 17(4), 602-633. DOI: 10.1179/1461957114Y.0000000066

* Lull, V., Micó, R., Rihuete-Herrada, C., & Risch, R. (2013). The La Bastida fortification: New light and new questions on Early Bronze Age societies in the western Mediterranean. Antiquity, 87(336), 1223-1237. DOI: 10.1017/S0003598X00049869

This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit www.anthropology.net/subscribe