Evolutionary Insights by Anthropology.net

Anthropology.net

A podcast about anthropology. www.anthropology.net

  1. 1 DAY AGO

    A Riddle in the Dark: Was This Small-Brained Hominin the First to Bury Its Dead?

    Paleoanthropology is a field of constant surprises, where the oldest certainties can be upended by a single discovery. For decades, the story of human evolution was a tidy progression: Bigger brains meant greater intelligence, which in turn led to complex behaviors like creating art, using fire, and, most powerfully, engaging in mortuary rituals. This story placed us—Homo sapiens—at the pinnacle, with our ancient cousins like Neanderthals following close behind. But a small-brained hominin from a South African cave system has complicated this narrative in the most profound way. For several years, the species known as Homo naledi has been at the center of one of the most intense debates in the study of human origins. The initial theory, popularized in a 2017 Netflix documentary, suggested that this species, with a brain no larger than a chimpanzee’s, had deliberately buried its dead. The claim was initially met with widespread skepticism among many independent experts. A significant criticism was that the remains could have simply been transported to their final resting place by natural forces, such as water flow. In science, extraordinary claims require extraordinary evidence. Now, a new study in the journal eLife revisits the case, providing a detailed reanalysis of the evidence. The research, led by Lee Berger and an international team, offers a more robust argument for a complex suite of behaviors that include the deliberate burial of the dead. The findings, which have convinced at least one of the original skeptical peer reviewers, are forcing the field to reconsider the fundamental relationship between brain size and the origins of ritual and symbolic thought. The Meticulous Taphonomy of a Burial To understand the controversy, one must look closely at the geological and taphonomic evidence from the Rising Star Cave system. The skeletal remains of Homo naledi were found deep within the Dinaledi Subsystem, a network of chambers and passages so narrow and challenging to navigate that it requires specialized cavers to reach. This location alone suggests that bodies did not simply wash in or fall from a surface entrance. The researchers focused on three distinct areas within the cave where concentrations of Homo naledi fossils were found: the Hill Antechamber Feature, the Dinaledi Chamber Feature 1, and the original "Puzzle Box" area. At each of these locations, the team meticulously studied the spatial arrangement of the bones and the composition of the surrounding sediment. Their analysis provided several lines of evidence that, when taken together, challenge the idea of natural accumulation. Perhaps the most compelling evidence comes from the state of the bones themselves. The fossils were found in articulated or semi-articulated positions, a phenomenon the researchers call "matrix-supported skeletal regions." This means that the bones of an individual were still held together by soft tissue when they were rapidly covered by sediment. This finding directly contradicts the hypothesis that the bodies decomposed on an open cave floor before being slowly covered by sediment, as decomposition would have caused the joints to disarticulate and the bones to scatter. The team's work also provides evidence that the remains were placed in pits that were intentionally dug. In the Hill Antechamber, the stratigraphic layers in the cave floor, which slope at a steep angle, are abruptly truncated at the edges of the fossil concentration. This pattern suggests that a hole was dug through the pre-existing layers before the body and new sediment were placed inside. Similarly, in the Dinaledi Chamber, a distinct layer of laminated orange silty-mudstone is interrupted by the feature containing the Homo naledi bones. This disruption is inconsistent with a natural depression and instead points to the deliberate excavation of a pit. The newly published work presents a minimal definition of "cultural burial" consisting of three components: * A hole or pit is dug by hominins into the sediment. * A body or body parts are placed into this feature by hominins. * The remains are covered (backfilled) by hominins. The evidence from the cave fits this definition. The new findings are so convincing that one of the anonymous peer reviewers, who had initially found the evidence for intentional burial "inadequate and unconvincing," reversed their position. n their revised manuscript, the authors have implemented substantial improvements in methodology, analytical depth, and overall presentation, which have effectively resolved the critical issues previously highlighted. Key gaps in the earlier version, such as the absence of detailed reconstructions of taphonomic processes, bone articulations, and displacement patterns, have been addressed with thorough analyses and clearer illustrations. The reviewer also noted that the new data now includes evidence that the bones were placed in human-made pits, directly addressing a prior concern. Rethinking the Hominin Mind The implications of this study reach far beyond a single cave system. If Homo naledi buried its dead approximately 241,000 to 335,000 years ago, it means a species with an average brain size of just 550 cubic centimeters was capable of a behavior previously attributed only to larger-brained hominins like Neanderthals and modern humans. This challenges a long-standing paradigm in anthropology, which has often treated brain size as the primary driver of complex cognitive and cultural behaviors. The question of why Homo naledi might have engaged in this behavior remains open. Did they possess a complex understanding of death or an emotional response akin to grief? The researchers are cautious about attributing modern human motivations to these ancient relatives, but they suggest that the behavior is a clear sign of an intentional and meaningful response to death. The paper also highlights other intriguing findings. In the Hill Antechamber, the researchers found a stone object positioned near an articulated hand, embedded in the sediment at an angle that could not have occurred naturally. While the study does not definitively conclude that this was a "grave good" intentionally placed with the body, its distinctive placement is intriguing and suggests a degree of forethought. The team also documented a number of engravings on a nearby cave wall that have been attributed to Homo naledi, adding to the picture of a species with complex social and cognitive capabilities. These findings suggest that the emergence of complex social behaviors was not a single, linear event tied to one hominin lineage, but rather a more complex story of convergent evolution in different species with very different cognitive architectures. As the study's authors note, the evidence forces us to confront an uncomfortable but necessary truth: the story of human evolution is not a simple, single path to our modern selves. It is a story of multiple hominin lineages, each with its own unique toolkit for making sense of their world and confronting the profound mystery of death. Additional Research * Martinón-Torres, M., d'Errico, F., Santos, E., Álvaro Gallo, A., Amano, N., Archer, W., Armitage, S. J., Arsuaga, J. L., Bermúdez de Castro, J. M., Blinkhorn, J., Crowther, A., Douka, K., Dubernet, S., Faulkner, P., Fernández-Colón, P., Kourampas, N., González García, J., Larreina, D., Le Bourdonnec, F.-X., MacLeod, G.,... & Lari, M. (2021). Earliest known human burial in Africa. Nature, 593(7857), 95-100. DOI: 10.1038/s41586-021-03457-8. This study documents the oldest known Homo sapiens burial in Africa, a child found in a deliberately excavated pit in a cave in Kenya, dating to approximately 78,000 years ago. * Pomeroy, E., Bennett, P., Hunt, C. O., Reynolds, T., Farr, L., Frouin, M., Holman, J., Lane, R., French, C., & Barker, G. (2020). New Neanderthal remains associated with the 'flower burial' at Shanidar Cave. Antiquity, 94(373), 11-26. DOI: 10.15184/aqy.2019.207. This research describes a new adult Neanderthal skeleton found at the famous Shanidar Cave in Iraq, showing articulated remains within a stratigraphic context that suggests intentional burial. * Sala, N., Pantoja-Pérez, A., Gracia, A., & Arsuaga, J. L. (2024). Taphonomic-forensic analysis of the hominin skulls from the Sima de los Huesos. The Anatomical Record, 307(9), 2259-2277. DOI: 10.1002/ar.24883. This paper explores the taphonomy of the thousands of hominin fossils from the Sima de los Huesos site in Spain, concluding that the accumulation of bodies was not due to a natural accident, but rather intentional disposal of corpses, predating the Homo naledi burials by hundreds of thousands of years. 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

    18 min

  2. 1 DAY AGO

    Beyond the Family Tree: How Genetic Admixture Rewrites the History of Language

    Linguists have long mapped the world's languages as grand family trees. They draw neat branches to show how Latin gave rise to French, Spanish, and Italian, or how a single Proto-Germanic root sprouted the distinct forms of English, German, and Swedish. This view, of languages passed vertically from one generation to the next, is a powerful way to visualize history. It is a story of inheritance, of ancestral words and grammars persisting through time, modified only slightly by each passing century. It is a clean and satisfying picture. But it is also incomplete. The reality of language is far messier. It is a story not just of descent but of borrowing. Throughout human history, populations have met, interacted, and mingled, and with them, their languages have done the same. Words leap from one language to another; new sounds are adopted; grammatical structures shift. This process is known as horizontal transfer, and it is a fundamental force in how languages evolve. Yet, for all its importance, it has remained a puzzle, a vast historical landscape shrouded in mist. How can we possibly measure the effect of contact when so much of human history remains unrecorded? A recent study published in Science Advances offers a new way to pierce through that mist. By turning to a different kind of historical record—the human genome—researchers have found a way to quantify the effects of population contact on language at a global scale. The analysis of this data suggests that the story of linguistic evolution is not just one of persistence and change, but of surprising and consistent patterns that transcend time, place, and the immense social complexities of human interaction. The Ghost of Encounters Past For centuries, the only way to study linguistic borrowing was through the circumstantial clues left behind in the historical record. A linguist might notice a pattern in the grammars of two unrelated languages in a certain region and infer that they must have once been in contact. The evidence for such contact, however, was often pieced together from fragmented historical accounts or geographical proximity, leaving large gaps in our understanding. This made it nearly impossible to draw global conclusions about how contact shapes language. The historical evidence was largely circumstantial, and a systematic, cross-cultural study of borrowing rates seemed out of reach. The team behind the new study, led by Anna Graff and Chiara Barbieri, sought a solution in the field of population genetics. Their premise was straightforward: if a population's genes can tell us about past mixing events, why couldn't they also tell us about the cultural exchange that likely took place at the same time? They proposed that genetic admixture—the presence of genetic material from two previously distinct ancestral populations in a single modern population—could serve as a reliable, independent proxy for population contact. To put this hypothesis to the test, the researchers analyzed the genomes of 4,768 individuals from 558 populations around the world. Using genetic analysis tools, they identified over 125 instances where modern populations showed significant genetic admixture from two different ancestral groups. This allowed them to create a list of "contact pairs," such as the descendants of Spanish and Quechua speakers in South America, whose genomes clearly showed the legacy of an ancient interaction. Crucially, by focusing on languages from different families, they could be certain that any shared linguistic traits were the result of borrowing, not shared ancestry. For each of these genetically-defined contact pairs, the researchers then drew on two extensive databases of linguistic features, covering grammar, phonology, and lexicon. By comparing the languages of the admixed populations with those of their ancestral sources, the team could precisely measure how much linguistic sharing had occurred. This approach bypassed the problem of missing historical records entirely, creating a systematic, global map of language contact and its outcomes. A Quiet, Global Consistency The most striking finding to emerge from this work was a quiet yet profound consistency. The researchers found that regardless of where in the world these populations came into contact, their languages became more similar to a "remarkably consistent extent". The probability of two languages sharing a feature state increased by approximately 4% to 9% in situations of genetic contact. This consistency held true across a wide range of demographic and geographic conditions. It was observed whether the contact took place between populations within a single continent, such as the contact between Bantu and Khoisan languages in Zambia, or between continents, as was the case with European colonialism in the Americas. The findings indicate a consistent link between the history of human populations and the history of their languages. The consistency of this effect suggests something fundamental about the process of linguistic change. It implies that the fact of contact itself is a more powerful and predictable force than the myriad specific details of that contact. The study's authors noted that the social dynamics, power imbalances, and geographical scale of a given encounter do not seem to alter the overall rate of borrowing in a significant way. It is as if there is a general, self-limiting rate of cultural diffusion that persists across all scenarios, constrained enough not to completely erase the vertical history of a language but powerful enough to reshape its structure. The Curious Case of the Unborrowable Trait For decades, the field of linguistics has held to certain assumptions about which features of a language are more likely to be borrowed. The conventional wisdom suggested that "matter borrowing," the transfer of concrete words, was common and easy, while "pattern borrowing" of sounds or grammatical structures was rare and difficult. The logic was tied to the human brain: while new vocabulary can be learned at any age, the core structures of grammar and phonology are thought to be acquired during a "critical period" in early childhood, making them less accessible to adults who initiate most borrowing. The meta-analysis of the Graff et al. study directly challenged this long-standing assumption. When the researchers broke down their findings by linguistic feature class, the results were not what was expected. The table below illustrates some of the surprising results. The most compelling contradiction appeared in the data on "Grammatical Categories" and "Lexical Classes". These features are notoriously difficult to acquire after early childhood, yet the study found that their borrowing rates were in a range similar to or even higher than "Lexical Semantics". This finding suggests that the social forces at play during contact may easily override what were once considered cognitive or developmental constraints. In situations with strong demographic imbalances, such as those associated with European colonialism, there is high pressure to assimilate to a high-prestige language. The adoption of a dominant group's grammatical categories may not be a simple cognitive act but a social one, a powerful signal of assimilation and a means of gaining social standing. The study posits that a language is not just a cognitive tool but a badge of group identity, and its features can be borrowed or rejected based on social necessity, regardless of their intrinsic difficulty. When Languages Push Back While the study found a consistent trend toward borrowing, it also revealed a compelling counter-narrative: sometimes, languages in contact actively reject convergence. This phenomenon, known in anthropology as schismogenesis, is a process of signaling divergence, where groups in contact use linguistic differences to assert a distinct identity. The study found a noticeable number of feature states that, instead of being shared, actually became less alike under contact, a sign of this deliberate diversification. A particularly interesting example of this dynamic appeared in the data on prosody, the rhythmic and tonal properties of speech. Prosody is a powerful marker of social belonging. The researchers found that in imbalanced, colonial-era contact, prosodic features were more likely to be borrowed, a sign of assimilation. However, in more socially balanced encounters, these same features showed a tendency for divergence, becoming a tool for distinguishing one group from another. This dual nature of prosody illustrates a deeper truth about language and identity. The same linguistic feature can be a signal of convergence in one context and a symbol of divergence in another, depending entirely on the social power dynamics between the groups. It shows that language change is not a passive process of absorption; it is an active negotiation of identity, played out through the subtle shifts in sounds, words, and grammar. A Legacy of Connection, and a Warning for the Future The findings of this study are not confined to the past; they resonate deeply with the present. The history of human migration is a testament to the power of contact, from ancient displacements of farmers to recent intercontinental movements. Our world is more interconnected than ever, and these same processes of borrowing, convergence, and divergence are at work. Consider the United States, which has historically been a polyglot nation driven by waves of immigration. Yet, it is also a place where immigrant languages frequently face extinction, often fading within a few generations as they are replaced by English. This dynamic is a modern echo of the processes the study documented. Contact can certainly lead to language loss, but as this research shows, it also reshapes the surviving languages, sometimes eroding their deeper structural diversity by making them more similar. As our world becomes increasingly globalized, t

    12 min

  3. 3 DAYS AGO

    Stones and Fire in the West African Savanna

    For centuries, the prehistory of West Africa has lingered in the shadows of better-studied regions. Europe’s caves brim with art and stratigraphy; East Africa’s rift valleys yield hominin fossils and ancient tools. By contrast, West Africa has offered far fewer windows into its past. The climate and geology have conspired to erase many traces of human life, leaving archaeologists with a patchwork record. Now, a site tucked into Senegal’s Falémé Valley is helping to fill that gap. Excavations at Ravin Blanc X (RBX) have revealed an Early Holocene workshop where hunter-gatherers knapped quartz into tools beside a small fireplace. Radiocarbon dates place this activity around 9,100 years ago. It is one of the rare Later Stone Age (LSA) sites in West Africa preserved with enough clarity to show how stone, fire, and environment intersected in daily life. “Stratification is crucial: it captures successive phases of occupation and provides key information on chronology, lifestyle changes, and climatic and environmental evolution,” notes Anne Mayor of the University of Geneva, who co-directed the project. A rare archaeological pocket The RBX site lies within a ravine whose sediments shielded the remains of an aceramic Later Stone Age occupation. In 2017, surface finds led researchers to test the site. Beneath later Neolithic deposits, they uncovered a layer dense with lithics and charcoal. The heart of this layer contained a fireplace and a knapping floor, intact after nearly 9,000 years. What the team found was not finished tools but debris. Flakes, cores, and fragments of quartz told the story of toolmaking in action. By refitting broken pieces, archaeologists could reconstruct the reduction sequences. Two main types of blanks were produced: broad, rectilinear flakes and narrower, elongated ones with oblique points. Retouching was rare; precision at the knapping stage meant the tools were already close to final form. The quartz itself was carefully chosen. Of the valley’s many sources, people selected microcrystalline blocks with predictable fracture patterns, demonstrating a practiced eye for stone quality. Stones in the savanna The RBX fireplace offered another glimpse of daily life. Charcoal analysis showed that the wood came from Detarium species, small trees common in dry savannas whose dense wood burns hot. Phytoliths—silica bodies from ancient plants—revealed a landscape of open grasslands dotted with palms and scattered trees. This was the onset of the African Humid Period, when rainfall transformed parts of the Sahel into more fertile terrain. Together, the evidence situates RBX’s occupants within a dynamic ecological transition. Their tools and fire hint at groups adapted to a savanna that was greener than today, yet still demanding in its seasonal rhythms. Shared traditions, distinct choices Comparisons with other sites show that the RBX toolkit was not unique. Technological parallels exist with Fatandi V in Senegal and Damatoumou 1 in Mali, pointing to a Sahelo-Sudanian LSA tradition. Yet contrasts emerge when comparing savanna groups with those in West Africa’s tropical forests. The latter show less standardization and more opportunistic toolmaking. “The microliths found at these savannah sites reveal sophisticated craftsmanship aimed at producing highly standardized, identical tools,” says Mayor. “Conversely, sites further south, in tropical forest settings, show different, more opportunistic technical choices.” Such differences suggest that by 9,000 years ago, cultural distinctions were already emerging between communities in contrasting environments. Why it matters The Ravin Blanc X site offers more than a single episode of tool production. It demonstrates that well-preserved LSA contexts in West Africa can exist and can illuminate cultural diversity at a critical juncture: the transition from foraging lifeways to the first ceramics, domestication, and Neolithic societies. By anchoring chronology with radiocarbon dates, RBX bridges the gap between the Late Pleistocene and the Holocene in a region where timelines have remained hazy. It underscores that the history of human ingenuity is not confined to Europe’s caves or Africa’s rift valleys. The people of the Falémé Valley were equally skilled at shaping stone and navigating changing landscapes. Related Research * Sorbini, G., et al. (2023). “Technological diversity in the Later Stone Age of West Africa.” African Archaeological Review. https://doi.org/10.1007/s10437-023-09568-0 * Huysecom, E., et al. (2012). “The emergence of pottery in Africa during the tenth millennium cal BP.” Journal of African Archaeology, 10(1): 43–65. https://doi.org/10.3213/2191-5784-10210 * Scerri, E. M. L., et al. (2016). “The West African Stone Age in the context of African prehistory.” Azania: Archaeological Research in Africa, 51(4): 507–537. https://doi.org/10.1080/0067270X.2016.1261741 * Lespez, L., et al. (2020). “Palaeoenvironments of the Falémé Valley (Senegal) and their impact on human settlement.” Quaternary International, 554: 95–111. https://doi.org/10.1016/j.quaint.2020.06.017 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

    14 min

  4. 3 DAYS AGO

    A Lone Ingot and the Trade Networks of the Iron Age Baltic

    In a windswept coastal field near Särdal, Sweden, archaeologists recently examined what at first seemed an ordinary lump of metal. Its plano-convex shape—a low dome with a flat base—resembled the ingots long associated with Bronze Age trade. Yet isotopic tests told a different story: this was no Bronze Age artifact, but a copper-zinc-tin-lead alloy typical of the Iron Age. The find, reported in the Journal of Archaeological Science: Reports by Serena Sabatini and colleagues, is the first complete plano-convex ingot identified from Sweden. When set beside ingot rods from northeastern Poland’s Iława Lakeland, it reveals a shared recipe for alloying that hints at much wider economic ties linking the Baltic world with Atlantic and continental Europe. “Due, in particular, to its shape and size, it seemed to us a Bronze Age artifact,” noted Serena Sabatini of the University of Gothenburg. “But the ingot turned out to be made of a copper-zinc-tin-lead alloy, typical of the Iron Age and later periods.” The ingot as artifact and signal Plano-convex ingots are best known from Bronze Age contexts across the Mediterranean, where they were produced for transport and exchange. To find one in Sweden—an isolated object with no archaeological context—posed interpretive challenges. To resolve them, the team turned to isotope geochemistry. By comparing trace elements and lead isotope ratios in the Särdal ingot with similar analyses from Polish finds, the researchers uncovered near-identical signatures. This suggested not only contemporaneity but also a shared metallurgical tradition. “Given the astonishing similarity of the metal composition in all those artifacts, we also managed to strengthen earlier hypotheses about contacts and networking in the Baltic area during the Nordic pre-Roman Iron Age,” Sabatini explained. Collaboration across borders The study highlights the role of collaboration in archaeometallurgy. Polish scholars had recently published data on Iron Age ingot rods, and only by comparing datasets could the Swedish find be placed within a coherent historical context. “Networking and international collaboration are also important to unveil patterns and data that would remain unknown when one looks exclusively at the local context,” said Sabatini. “Without the successful collaboration with our Polish colleagues, we would never have achieved such remarkable results.” Iron Age networks beyond Scandinavia The metallurgical match between Sweden and Poland points to more than isolated experiments in alloying. It suggests structured exchange, perhaps even organized distribution of copper alloys across the Baltic. Such trade would have been essential in a world where access to ores, especially tin, was uneven and often distant. By the Nordic pre-Roman Iron Age (ca. 500 BCE–CE 1), Scandinavia was already tied into far-flung exchange networks that connected the Atlantic façade, the Baltic, and continental Europe. Objects of Mediterranean origin occasionally reached northern Europe; amber and furs traveled south. Metal, always a commodity of strategic importance, was the medium through which these exchanges were made tangible. What a single ingot tells us In isolation, the Särdal ingot might have been written off as a curiosity. But when analyzed and contextualized, it becomes a key to understanding the broader economic and cultural world of the Iron Age Baltic. Objects like this ingot and the Polish rods illuminate how trade and metallurgy worked together to weave the pre-Roman north into continental patterns. Related Research * Ling, J., & Stos-Gale, Z. (2015). Isotope evidence for the origin of metals in Late Bronze Age Europe. Journal of Archaeological Science, 61, 246–259. https://doi.org/10.1016/j.jas.2015.06.001 * Nørgaard, H. W., Pernicka, E., & Vandkilde, H. (2019). On the trail of Scandinavia’s early metallurgy: Provenance, transfer and mixing. PLOS ONE, 14(7), e0219574. https://doi.org/10.1371/journal.pone.0219574 * Radivojević, M., Rehren, T., Pernicka, E., Šljivar, D., Brauns, M., & Borić, D. (2010). On the origins of extractive metallurgy: New evidence from Europe. Journal of Archaeological Science, 37(11), 2775–2787. https://doi.org/10.1016/j.jas.2010.06.012 * Sabatini, S., & Bergerbrant, S. (2019). Trade and Civilisation: Economic Networks and Cultural Ties, from Prehistory to the Early Modern Era. Cambridge University Press. https://doi.org/10.1017/9781108563709 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

    14 min

  5. 3 DAYS AGO

    Voices From Deep Time

    he Anthropology of Sound Language is often hailed as humanity’s signature invention, the trait that makes us unique. But if we listen carefully to the evolutionary past, the roots of speech run far deeper than words. For anthropologists and archaeologists, language isn’t just a system of grammar and vocabulary. It is a survival tool, a social bond, and a window into cognition. To understand where it came from, researchers increasingly look not just to fossilized skulls or stone tools, but to the living voices of other species. Two new studies add to this growing chorus. One, published in NeuroImage by Boglárka Morvai and colleagues, suggests that the ability to detect vocalizations—and to tell our own kind apart from others—is an ancient mammalian inheritance, shared by species as different as humans, dogs, and pigs. Another, published in PNAS by Renata Biazzi and collaborators, reveals how rapid postnatal brain growth in humans and marmosets may explain why both species babble their way into language. Taken together, these findings place human speech on a broader evolutionary map: from deep-time mammalian sound detection to the peculiar, fragile window of infant brain development that made vocal learning possible. Voices Across Mammals: A Shared Heritage The Hungarian team behind the NeuroImage study asked a deceptively simple question: how do mammalian brains respond to voices? To find out, they wired up humans, pet dogs, and companion pigs with EEG electrodes, and played back a series of sounds: sighs, coughs, barks, grunts, and neutral noises. The results revealed a two-step neural process. Within 200 milliseconds, human and pig brains showed heightened activity whenever they heard a vocal sound—whether from their own species or another. Then, a little later, all three species (including dogs) showed a distinct response when the sound belonged to their own kind. This suggested that the ability to prioritize voices, and then to sort them into familiar and unfamiliar categories, is not a human innovation. It likely dates back some 90 million years, to the last common ancestor of these diverse mammals. “Conspecific vocalization sensitivity may have ancient evolutionary roots,” the team concluded. In short: mammals have been listening closely for a very long time. Babbling Brains: Why Humans (and Marmosets) Talk But recognizing voices is not the same as learning to produce speech. That leap—babbling, imitating, and eventually conversing—is rare in the animal kingdom. Apart from humans, only a handful of birds and one other primate, the marmoset, show clear signs of vocal learning in infancy. The PNAS study sought to understand why. By comparing developmental data across four primates—humans, marmosets, chimpanzees, and rhesus macaques—the researchers found that humans and marmosets share a striking pattern: their brains grow unusually fast just after birth. That accelerated growth means that infants experience the world, and the social responses of caregivers, at a time when their neural circuits are still highly malleable. Marmoset parents, much like human families, answer their babies’ squeaks and coos with vocal replies. This back-and-forth accelerates the young monkeys’ progress from babble to adult-like calls. The same dynamic underlies the human journey from cooing to words. As neuroscientist Asif Ghazanfar has put it, “That means the social environment an infant is born into has a tremendous influence” on language learning. In evolutionary terms, humans didn’t invent this strategy out of nowhere—we share it with a tiny monkey in Brazil. The Long Evolution of Talking For anthropologists, these studies reshape how we think about speech. Voice recognition circuits are ancient, perhaps as old as mammals themselves. Babbling brains, nurtured by caregivers, arose later, but not uniquely in our lineage. Together, they form the scaffolding for human language. The archaeological record reminds us that spoken language leaves no fossils. But by combining neuroscience with evolutionary biology, researchers are uncovering the hidden continuities that connect our conversations today with the calls of pigs, the barks of dogs, and the chatter of marmoset infants. Speech, it seems, is both deeply ancestral and oddly fragile: rooted in mechanisms shared across millions of years, yet dependent on the fleeting window of infancy to take shape. Between these two poles—ancient recognition and infant learning—lies the story of how humans became the most talkative species on Earth. 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

    13 min

  6. 5 DAYS AGO

    When Mutations Aren’t Accidents

    For more than a century, biologists have described evolution as a two-step dance: mutations arise randomly, and natural selection decides which survive. Randomness, in this view, is the engine of genetic variation, producing an endless supply of accidents, some beneficial, many neutral, and others lethal. But new research suggests that not all mutations fit this script. A study published in Proceedings of the National Academy of Sciences by an international team led from Israel and Ghana argues that some mutations appear not by accident but in patterns shaped by long-term pressures. Their findings come from the APOL1 gene, a locus with a fraught evolutionary history. Variants in APOL1 protect against Trypanosoma parasites, which cause African sleeping sickness, but they also increase the risk of kidney disease when inherited in pairs. “The new findings challenge the notion of random mutation fundamentally,” said Adi Livnat of the University of Haifa, senior author of the study. A mutation with two faces The APOL1 variant under scrutiny has long puzzled geneticists. In West and Central Africa, where Trypanosoma infections have historically been a deadly force, this mutation provides a clear survival advantage. But outside regions where the parasite is common, the same mutation seems less prevalent, as its protective benefits are irrelevant and its risks remain. If mutations arise purely at random, researchers expected the APOL1 variant to appear at similar baseline rates worldwide, only later spreading in Africa under parasite pressure. Instead, the team’s ultra-sensitive method showed that the mutation originates more frequently in African populations than in Europeans. Even more striking, the change occurs in exactly the part of the gene where it confers parasite resistance. This pattern echoes earlier findings on the HbS mutation, which guards against malaria while causing sickle-cell anemia. Both cases suggest that some mutations arise with a kind of internal logic, linked to genomic context and environmental history. Beyond randomness and Lamarck Historically, evolution has been cast between two poles: Darwinian mutation-and-selection versus Lamarck’s discredited idea that organisms directly tailor their genes to environmental needs. The new study proposes something different: that genomes themselves may have a built-in tendency to produce useful changes, honed over generations. In this view, the genome isn’t just a passive ledger of chance accidents. Instead, it’s an active system where mutations can be guided by the accumulated “experience” of past selective pressures. “At each generation, mutations arise based on the information that has accumulated in the genome up to that time point,” Livnat and colleagues write. The researchers describe this as a form of natural simplification. Over evolutionary time, genetic interactions that repeatedly prove useful can become “hardwired” into the DNA through mutational processes. This mechanism doesn’t require foresight by organisms, but it means mutations aren’t always scattershot. The case of gene fusions The team points to gene fusions as an example. Traditional thinking held that genes fuse randomly when DNA segments happen to break and rejoin. But studies show that genes which frequently work together in cellular networks are more likely to fuse—suggesting that the 3D architecture of the genome brings them together in ways that favor functional outcomes. Seen this way, mutations aren’t just noise. They can be the crystallization of long-term biological “conversations,” streamlining regulatory systems into new, inheritable units. Implications for anthropology and medicine For anthropologists, this study opens new possibilities for thinking about human evolution. If some mutations arise preferentially in response to enduring pressures, then episodes like the spread of malaria resistance in Africa or lactose tolerance in Europe may need re-examining. Did these mutations simply occur at random, or did genomic architecture make them more likely in populations where they mattered most? The medical implications are equally large. Nonrandom mutational processes could help explain why certain populations bear disproportionate burdens of genetic disease, and why some protective traits cluster geographically. A shift in evolutionary thinking While controversial, the results encourage scientists to look more closely at mutation as a process with its own rules, not merely raw material for selection. “Understood in the proper timescale, an individual mutation does not arise at random nor does it invent anything in and of itself,” Livnat argues. Instead, mutations may emerge from a long history of genomic interactions, layered generation by generation. If so, then the story of evolution is not only about chance and filtering, but also about the deep memory encoded within the genome itself. Related Research * Stern, D. L. (2010). Evolution, Development, and the Predictable Genome. Roberts and Company. https://doi.org/10.1086/656796 * Monroe, J. G., Srikant, T., Carbonell-Bejerano, P., Becker, C., Lensink, M., Exposito-Alonso, M., ... & Weigel, D. (2022). Mutation bias reflects natural selection in Arabidopsis thaliana. Nature, 602(7896), 101–105. https://doi.org/10.1038/s41586-021-04269-6 * Livnat, A. (2013). Interaction-based evolution: how natural selection and nonrandom mutation work together. Biology Direct, 8(24). https://doi.org/10.1186/1745-6150-8-24 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

    21 min

  7. 5 DAYS AGO

    How the Slavic Migrations Reshaped Europe’s Genetic and Cultural Landscape

    In the sixth century CE, Slavic groups began to appear in the written accounts of Byzantine chroniclers. Within a few generations, they spread across a vast region from the Elbe to the Volga, and from the Baltic to the Balkans. Yet for centuries, historians and archaeologists puzzled over a basic question: did the spread of Slavic culture reflect the movement of people, or simply the diffusion of language and traditions among existing populations? Two major genomic studies now bring clarity to this debate. A team led by Joscha Gretzinger and colleagues, writing in Nature, analyzed genome-wide data from 555 ancient individuals across Central and Eastern Europe. Meanwhile, another study by Ilektra Schulz and co-authors in Genome Biology focused on 18 individuals from South Moravia, a region that later became the heartland of the ninth-century Moravian principality. Together, the findings paint a detailed picture of how large-scale migration shaped Europe’s genetic and cultural landscape during the Early Middle Ages. The Scale of Movement The genetic evidence shows that beginning in the sixth century, populations carrying ancestry from eastern Europe—particularly areas around present-day Belarus and Ukraine—moved westward and southward. This was no trickle. In regions such as eastern Germany, Poland, and Croatia, more than 80 percent of the local gene pool was replaced during this period. In South Moravia, the data tell a similar story. Individuals from the fifth century carried a wide spectrum of ancestries, from Mediterranean to Scandinavian. But by the seventh century, this diversity gave way to a more homogeneous profile closely resembling modern Slavic-speaking populations. As Schulz and colleagues note, the results are “incompatible with theories of strict local continuity,” supporting instead the arrival of new populations linked to the Prague-Korchak cultural horizon. Social Worlds in Transition This genetic transformation was not accompanied by the kind of empire-building often associated with migration in antiquity. Instead, archaeogenetic and archaeological evidence suggests that early Slavic communities were built around flexible kinship networks and local alliances. In eastern Germany, new extended family groups became the backbone of society, organized around patrilineal descent. In the Balkans, by contrast, migrants mixed with local populations, producing hybrid communities where old and new traditions persisted side by side. These findings help explain why early Slavic communities left such modest archaeological signatures—small villages, handmade pottery, and cremation burials. Their strength may have lain not in imposing dominance but in adaptability. As medievalist Walter Pohl puts it, the Slavic migrations resembled, “a demic diffusion or grass-root movement, often in small groups or temporary alliances, settling new territories without imposing a fixed identity or elite structures.” Continuities and Legacies One of the most striking outcomes of these studies is the persistence of early medieval Slavic ancestry into the present day. Among the Sorbs, a Slavic-speaking minority in eastern Germany, genetic profiles remain closely aligned with the populations that settled the region over a millennium ago. In Poland, the genetic shift of the sixth and seventh centuries laid the foundation for the ancestry of modern Poles, Ukrainians, and Belarusians. At the same time, regional variation remained the norm. In Croatia, for example, Slavic-related ancestry makes up only part of the modern gene pool, reflecting a long history of intermarriage with diverse local groups. In Moravia, genetic continuity from the seventh century onward suggests that once established, Slavic communities remained relatively stable, forming the basis for later political entities such as the Moravian principality. A Different Kind of Migration Story The genomic evidence reframes the Slavic expansion not as a story of conquest, but as one of demographic transformation. Entire families moved together, women and men contributing equally to the gene pool. Rather than replacing local elites, early Slavs integrated with them in some regions, or built new communities where space was available in others. Their success lay in flexibility and resilience during a period of political fragmentation and ecological stress. As Johannes Krause of the Max Planck Institute for Evolutionary Anthropology observes, “The spread of the Slavs was likely the last demographic event of continental scale to permanently and fundamentally reshape both the genetic and linguistic landscape of Europe.” Related Research Other archaeogenetic work complements these findings: * Mathieson, I., et al. (2018). The genomic history of southeastern Europe. Nature, 555, 197–203. https://doi.org/10.1038/nature25778 * Veeramah, K. R., et al. (2018). Population genomic analysis of elongated skulls reveals extensive female-biased immigration in Early Medieval Bavaria. PNAS, 115(13), 3494–3499. https://doi.org/10.1073/pnas.1719880115 * Järve, M., et al. (2023). Genetic continuity, isolation, and local adaptation in the people of the eastern Baltic. Current Biology, 33(4), 739–751. https://doi.org/10.1016/j.cub.2022.12.028 Together with the new research, these studies highlight how movements of people, not just ideas, profoundly shaped the genetic and cultural map of Europe. 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

    20 min

  8. 5 DAYS AGO

    The Blue Shadows of Dzudzuana

    In the foothills of the Caucasus, archaeologists have recovered something unusual from Dzudzuana Cave: tiny traces of indigotin, the molecule that produces indigo blue. The residues clung to pebbles used as grinding tools 34,000 years ago. They came not from food, but from the leaves of Isatis tinctoria L.—a plant better known as woad. This is the first evidence that Upper Paleolithic groups intentionally processed a non-nutritional plant to extract compounds for purposes beyond survival. For archaeologists, it is a rare window into how Homo sapiens looked to plants not just for calories, but for color, healing, and meaning. “Rather than viewing plants solely as food resources, this study highlights their role in complex operations, likely involving the transformation of perishable materials for use in different phases of daily life,” noted archaeologist Laura Longo of Ca’ Foscari University of Venice, who led the research. A cave, some pebbles, and unexpected color Dzudzuana Cave, tucked into the Georgian Caucasus, has long yielded evidence of early modern human life. Excavations in the early 2000s recovered unknapped stone pebbles that had been used for grinding. Initially, the goal was to identify what these tools processed. Microscopic and chemical analysis revealed starch grains and wear consistent with soft plant material. Then came a surprise: blue residues concentrated in the worn zones. Advanced spectroscopy confirmed that the pigment was indigotin. The chemical forms when oxygen reacts with glycoside precursors in woad leaves during crushing. This means Paleolithic groups intentionally processed the plant, though its leaves have no nutritional value. Woad in the Paleolithic imagination The question is why. Isatis tinctoria has a deep history as both a dye and a medicinal plant. Medieval Europeans used it to produce blue textiles, while traditional remedies valued it for anti-inflammatory and antimicrobial properties. At Dzudzuana, the blue residues hint at similar possibilities. The pigments may have been used to color fibers, skins, or bodies. They may also have been part of medicinal or ritual practices, with color serving as a marker of power or protection. What matters most is the evidence of choice. These humans invested time and effort into transforming plants for purposes that reached beyond nutrition. Experiments in replication To test the idea, Longo’s team ran replicative experiments. They gathered river pebbles near the cave, cultivated woad, and crushed the leaves. The resulting residues matched the archaeological samples: faint blue fibers clinging to pores in the stone. The work showed that the Paleolithic pebbles could have trapped and preserved pigment for tens of thousands of years. “Our multi-analytical approach opens new perspectives on the technological and cultural sophistication of Upper Paleolithic populations, who skillfully exploited the inexhaustible resource of plants,” Longo explained. A glimpse of complex behavior These findings broaden the picture of Paleolithic ingenuity. Humans at Dzudzuana were not just hunters or gatherers of staples. They were chemists of the forest, experimenting with plants whose properties spoke to senses, bodies, and perhaps spirits. For anthropologists, the residues suggest a cultural world in which plants shaped identities, rituals, and aesthetics. The traces of blue are fragile, but they point to a capacity for abstract thinking, planning, and symbolic action long before agriculture or writing. Related Research * Hardy, K., Buckley, S., Collins, M. J., Estalrrich, A., Brothwell, D., Copeland, L., García-Tabernero, A., et al. (2012). Neanderthal medics? Evidence for plant-based dietary and medicinal practices. Naturwissenschaften, 99(8), 617–626. https://doi.org/10.1007/s00114-012-0942-0 * Power, R. C., Salazar-García, D. C., Rubini, M., Darlas, A., Havarti, K., Walker, M., & Henry, A. G. (2018). Dental calculus indicates widespread plant use within the stable isotope ecology of Upper Paleolithic humans. Nature Communications, 9, 5127. https://doi.org/10.1038/s41467-018-07282-0 * Cagnato, C. (2019). Plant dyes in the archaeological record: Their emergence, identification, and implications. Journal of Archaeological Method and Theory, 26(1), 219–258. https://doi.org/10.1007/s10816-018-9361-0 * Radini, A., Cummings, L. S., Buckley, S., Macchiarola, M., & Hardy, K. (2019). Human use of plants for non-nutritional purposes: Dental calculus evidence from prehistoric Europe. Antiquity, 93(367), 405–420. https://doi.org/10.15184/aqy.2019.31 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

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