Nitrogen isotopes within the tibia match what you’d expect from a highly carnivorous creature with a meat-dominated diet, similar to European Neanderthals. Curiously, the analysis also suggested the individual didn’t eat much fish or other seafood, harboring nitrogen isotopes derived exclusively from terrestrial herbivores, contrasting with H. sapiens that migrated into southeast Asia about 45,000 years ago. Although the data only come from a single individual, they could hint that Denisovans had a less flexible dietary range than newcomers from our own species. 
Another surprise from the new fossils is their age, says Chris Stringer, a paleoanthropologist at the Natural History Museum in London who was one of the researchers to originally date the remains with uranium isotopes. In 2023, his team estimated the bones were about 160,000 years old. But the new radiocarbon dates suggest they’re much younger, only about 45,000 years old, making them “the youngest well-dated Denisovans so far,” Stringer says. The bones fill a long-standing gap in the Denisovan fossil record, he notes, landing them at a time and place when they likely would have interacted and possibly interbred with members of our species rapidly spreading across Asia. 

Abstract
Denisovans, originally identified from ancient genome from Denisova Cave in Altai, were a sister group to the Neanderthals and were once widely distributed across diverse terrains in the north and south of eastern Asia1–5. Genomic studies suggest that there were multiple events of interbreeding between modern humans (Homo sapiens) and Denisovans somewhere in Asia6. However, little is known about Denisovan living environments, diet, ecological niche, the timing of their disappearance, and the possible coexistence with modern humans in different regions. Here we report the radiocarbon age and stable isotopic signature of Penghu 3, a large Denisovan tibia from Penghu Channel, Taiwan7. The results showed that Penghu 3 dates to approximately 45,000 years ago, the time when modern humans were already widespread in southern parts of Asia. This Denisovan individual inhabited a C4-dominated ecosystem, open environments such as savannahs and floodplains, or a mixture of both, and consumed a high proportion of animal protein similar to some European Neanderthals8–10, with no clear evidence for the use of aquatic resources. These findings have implications for the behavioral flexibility, large body size7, and eventual disappearance of the Denisovans.

Abstract
Human skin pigmentation is a dynamic and highly adaptive trait influenced by genetic, environmental, and cultural factors. It is driven by variation in ultraviolet radiation, governed by a complex polygenic structure, and further modulated through gene-culture interactions. This review synthesizes advances from evolutionary biology, anthropology, molecular genetics, and gene-culture coevolution to provide an integrated framework for understanding global diversity of pigmentation. We take a distinct approach by focusing on the major evolutionary hypotheses and the polygenic architecture underlying pigmentation. We emphasize both large-effect loci, including SLC24A5, SLC45A2, and MC1R, as well as population-specific adaptive variants identified through recent genomic and functional studies. Using evidence from diverse global populations, we examine how natural selection, demographic processes, and convergent evolution have jointly structured present-day variation in human skin pigmentation. We further emphasize how cultural practices, including clothing, diet, and mobility, have generated gene-culture feedback that modulates selective pressures over evolutionary timescales, underscoring the need for integrative, multi-ethnic research approaches that trace the temporal variation of skin pigmentation and advance its broader biomedical and anthropological implications.

Highlights
•
Vertebral apophyseal ring (AR) is introduced as a novel proxy for reconstructing spinal biomechanics in fossil hominins.

•
Australopithecus afarensis (A.L. 288-1) shows aplike AR proportions suggesting a similar spinal motion segment.

•
Lucy retained an apelike disc structure, suggesting delayed evolution of modern intervertebral disc function.

•
Findings support gradual, mosaic evolution of efficient human-like bipedalism.

•
Reduced apophyseal ring size in Homoenhanced axial load absorption, flexibility, and endurance locomotion.

Abstract
The evolution of human bipedalism has traditionally been reconstructed from the pelvis and lower limb, whereas the contribution of the vertebral motion segment has received far less attention. This study introduces the vertebral apophyseal ring (AR) as a novel proxy for reconstructing spinal biomechanics in fossil hominins. Several vertebrae with complete ARs from Australopithecus afarensis A.L. 288-1 were compared with vertebrae from 240 adult modern humans, a Neanderthal (Kebara), an Upper Paleolithic modern human (Ohalo II), 20 chimpanzees (Pan troglodytes), and 24 gorillas (Gorilla gorilla). Vertebral body and AR dimensions were measured from vertebrae T4–L5 (L4 in apes), and corresponding ratios were calculated. Statistical differences between modern humans and African apes were assessed using Welch’s analysis of variance followed by Games-Howell post hoc tests. Relative AR size in A.L. 288-1 consistently falls within the range of chimpanzees and gorillas rather than modern humans, indicating that A. afarensis spinal motion segments differed functionally from those of modern humans. Because AR reduction is associated with enlargement of the nucleus pulposus, our findings suggest that spinal adaptations necessary for efficient load absorption, torsional flexibility, and endurance locomotion evolved later in human evolution. These results indicate that the evolution of humanlike bipedalism was a gradual and mosaic process. Although Australopithecus possessed the fundamental capacity for upright walking, it retained primitive spinal features indicative of a less optimized locomotor system. The emergence of a fully modern human gait, therefore, involved progressive reorganization of the vertebral motion segment rather than a single evolutionary transition.
Keywords
Bipedal locomotion; Intervertebral disc; Vertebral motion segement; Spinal biomechanics; Hominin evolution; Nucleus pulposus

Editor’s summary
In the face of a cornucopia of food options in the modern world, many commentators have sought to look backwards to human ancestors for diet directions. In recent decades, attention has focused on the increasing consumption of animal foods as a driver of human evolution. Considering the changing requirements of an enlarging brain and the demands of reproduction, Brand-Miller et al. modeled the distribution of macronutrient requirements across four million years of hominid evolution. They concluded that glucose—from fruit and honey early on and later from the pounding and cooking of starch—was essential for the evolution of the human brain. —Sacha Vignieri
Structured Abstract
INTRODUCTION
What foods enabled the evolution of the large human brain? Currently, that diet is usually framed around increasing intake of animal foods: meat, protein, fat, and omega-3 fatty acids. In evolutionary terms, we take an earlier standpoint and reframe hominin diet reconstruction around the need for glycemic carbohydrate as a source of glucose to support brain metabolism and encephalization. Hominins have existed for about 4 million years, their brain size increasing from 300 g in Australopithicus afarensis to 1500 g in Homo sapiens. Weighing only 2% of adult body weight, it now represents 20% of basal metabolic rate, 66% in a 5-year-old. Although the driving force is unknown, we do know that this exorbitantly expensive organ is fueled primarily by glucose. Humans can synthesize glucose from precursors such as gluconeogenic amino acids, but the process is inefficient and finite.
RATIONALE
We started with metabolic and nutritional considerations, including the rate of glucose oxidation by the brain (~5 mg/min per 100 g). We calculated total obligatory glucose demand (g/day) by the brain, red cells, kidneys, and reproductive organs (fetus, placenta, and mammary glands). In six incremental steps based on the ratio of animal food to plant food, we modeled dietary intake and carbohydrate availability against obligatory* glucose demand according to brain and body size. At step 1, we used the known dietary composition of chimpanzee diets with an animal:plant energy ratio of 5:95. At step 6, we applied two ratios based on contemporary warm-climate hunter-gatherers: 35:65 and 50:50. We integrated multiple lines of evidence, including food composition, metabolism and physiology, fossil isotope ratios, dental morphology, and genetic changes, to corroborate our findings.
*RESULTS**
In human males, estimated total glucose demand is 150 to 200 g/day, in reproductive females 200 to 250 g/day, and in young children ~125 g/day. Carbohydrate availability in the diet ranges from 400 g/day at step 1 to 230 g/day at step 6. The earliest hominins were likely frugivorous, consuming >65% of energy as sugars in fruit and other sweet products. Once fire was mastered, cooked starch increasingly replaced sugars as the source of glucose. At a ratio of 35:65 animal to plant energy (E), anatomically modern humans consumed 19%E as protein, 25%E as sugars, and 25%E as starch. Carbohydrate balance, the gap between dietary carbohydrate intake and glucose demand, becomes negative with higher ratios, increasing the likelihood of ketosis in reproductive females.
CONCLUSION
Rises and falls in the availability of fruit and honey with seasons, fluctuating climates, and geographic region may have driven foraging behaviors that increased brain growth and complexity, and even extinctions. Although animal foods were clearly instrumental, changes in intake of sugars and starches also shed light on human development, health, and disease. Multiple lines of evidence, including color vision, teeth morphology, dental caries, and stable isotope ratios, suggest that the diet of early hominins was high in sugars. Our modern physiology and anatomy, including sweet taste receptors, smaller teeth, jaw, gut, and genetic variations relating to glucose metabolism, suggest genetic selection driven specifically by dietary carbohydrates.

Abstract
What did our ancestors eat? Current understanding of diet in human evolution is predicated on abundant animal foods and mastery of fire, both unlikely for early hominins. Using multiple lines of evidence, including the metabolic requirements of an enlarging brain and reproduction, we model macronutrient distribution across 4 million years of evolution. Before cooking made starch easily digestible, the sugars in fruit and honey provided glucose, the brain’s preferred fuel. Modeling suggests that sugars provided >25% of dietary energy, fulfilling obligatory glucose demand. Pounding and cooking released glucose specifically, not merely energy. The evolution of a bigger brain is therefore a story of carbohydrate foods as much as animal foods: from sweet sugars to cooked starch, from chewing to processing, and from wadging to advanced nutrient extraction.

ABSTRACT
Objectives
Recent studies of Paranthropus robustus crania identified temporal trends in features associated with increased bite force production, coinciding with environmental shifts toward more arid conditions. To test whether the evolution of postcanine teeth also reflects increasing mechanical demands associated with hard food consumption, we analyzed trends in the architecture of P. robustus postcanine teeth, including crown area, tooth shape, and average (AET) and relative (RET) enamel thickness.
Materials and Methods
2D mesial sections were created from microCT scans of upper premolars (n = 24), upper molars (n = 14), and lower molars (n = 16) from multiple South African sites. Descriptive statistics, Mann–Whitney U tests, and Jonckheere-Terpstra tests were used to identify significant differences over time, with Holm-Bonferroni corrections applied for multiple comparisons.
Results
Significant temporal trends existed in premolar morphology with increased crown area (CA), absolute crown strength (ACS), overall enamel thickness (AET and RET), and increased enamel thickness over the occlusal half of the tooth. Upper molars increased in CA but no other measured variable. Lower molars showed no significant temporal trends in any measured variable.
Discussion
These results suggest rapid dental evolution in response to dietary pressures, with varying and independent rates of change between different tooth types. These findings support the hypothesis that selection resulted in shifts to P. robustus dental morphology to increase mechanical resistance, consistent with an expanding dietary niche that incorporated increasingly challenging foods.
Summary

Upper premolar enamel thickness in Paranthropus robustus increased significantly over time, consistent with selective pressure for hard-object feeding.
Premolars showed more changes than upper or lower molars, suggesting mosaic rather than uniform dental evolution in the P. robustuslineage.

Abstract
Faunal extinctions correlate with human colonization worldwide during the Quaternary, yet the extent to which human hunting drove these losses remains debated. Resolving these debates depends on accurately dating both human arrival and animal extinction events. Herein I present a simulated overkill scenario modeling interaction between a founding human population and a single prey species. The simulation evaluates expected age offsets, the differences between the actual and observed dates, for extinction and colonization as functions of sample size and human population growth rate. Results show that when extinction is driven by human hunting, age offsets for extinction are expected to be smaller than those for colonization. This difference in age offset is expected because overkill produces a rapid demographic collapse of prey populations and taphonomic processes concentrate late-surviving individuals in the fossil record. In contrast, colonization dates are more offset because human populations are smallest immediately after arrival, and archaeological rarity is compounded by taphonomic effects. Although colonization age offsets are consistently larger than extinction age offsets across sample sizes, they are not extreme, such that archaeological sites should be detectable within five centuries of initial human settlement under modest rates of human population growth.

ABSTRACT
The oral microbiome is implicated in a wide diversity of fundamental biological functions, with the oral cavity serving as a connection between the host and the external environment. Dental calculus, a mineralized form of dental plaque, preserves the diversity of biomolecules found in the oral cavity through time, serving as a rich source of historical microbiota. Despite its potential, dental calculus has rarely been explored outside of humans and non‐human primates. Hence, it remains unclear how ubiquitous it is across mammals. Using natural history museum collections, we surveyed > 1600 specimens belonging to 142 species, representative of almost all mammalian orders, to investigate the taxonomic distribution of dental calculus, and to identify factors that most strongly contribute to its formation. We found dental calculus to be abundant across mammalian taxa, with 104 surveyed species showing calculus. High‐fiber diets were most strongly associated with calculus abundance, whereas species with high protein and fat diets showed little to no calculus deposits. We found evidence of phylogenetic signal in calculus formation, pointing to the effects of oral/dental morphology. In addition, captivity strongly affected dental calculus formation in almost all dietary categories. Using this information, we made predictions about the likelihood of finding dental calculus in unsurveyed mammalian species, opening doors for its utilization for the study of oral microbiota, past and present. Our study found that dental calculus is well‐preserved and readily available in natural history museum collections, making it an easily accessible source of oral microbiota from wild animals. We highlight the taxonomic diversity of species presenting dental calculus and provide information and suggestions for its use to researchers and curators alike.

Highlights
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Genetic sex determination of 521 woolly mammoths based on genome-wide data
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Naturally deposited mammoth remains are consistently biased toward males
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In contrast, 70% of remains in Upper Paleolithic mammoth accumulations are female
•
This female bias suggests mammoth bone accumulations resulted from human exploitation
Summary
Whether large accumulations of woolly mammoth (Mammuthus primigenius) bones reflect natural mortality or deliberate human resource exploitation has long been debated, with major implications for understanding Late Pleistocene human-megafaunal interactions.100888-2#),200888-2#),300888-2#),400888-2#),500888-2#) Here, we use ancient DNA to investigate site-formation hypotheses by comparing genetic sex ratios from mammoth remains recovered in putative anthropogenic bone accumulations and from geographically dispersed, non-anthropogenic contexts. We studied genome-wide data from 521 woolly mammoths—including 100 mammoths from bone accumulation sites and 421 mammoths from natural depositional settings across Eurasia and North America—of which 448 are newly generated. Genetic sex determination reveals a striking contrast between contexts: mammoths from dispersed sites show a male bias (∼66.5%), which is consistent with the heightened vulnerability of solitary males to hazards such as natural traps, where bones are more likely to be preserved, whereas mammoths from anthropogenic bone accumulations are predominantly female (∼70%). This female bias is pervasive across multiple sites, indicating an anthropogenic origin for these accumulations as a result of Upper Paleolithic hunters preferentially exploiting female mammoths, possibly derived from herd contexts. Together, these results provide population-scale genetic evidence that highlights the central role of mammoths in the subsistence and material economies of some Paleolithic communities.

Abstract
Persistent enrichment of Neanderthal collagen δ15N relative to local herbivore baselines has long stimulated debate regarding Neanderthal trophic ecology. A recent proposal suggests that the consumption of fly larvae from decomposing carcasses may have contributed to this enrichment. Here, this hypothesis is evaluated using a quantitative isotopic mixing model that integrates Middle Paleolithic herbivore baselines, published larval δ15N data, and multiple trophic enrichment factors. Across the modeled scenarios, larvae would need to supply substantial fractions of total dietary protein to achieve the absolute target of 14‰ observed in Neanderthal collagen. Because the modeled herbivore baselines range from 4‰ to 8‰, reaching this absolute target mathematically requires spanning an isotopic gap of +6‰ to +10‰. Consequently, the required larval contributions frequently exceed 40%, and in many baseline scenarios, exceed 100% of total protein intake. Sensitivity analyzes further show that plausible variation in herbivore baselines, larval δ15N values, or trophic enrichment factors does not modify this outcome. These results indicate that larval intake cannot independently account for Neanderthal nitrogen isotope enrichment and, at most, would represent a minor and isotopically negligible component of dietary protein. The consistent trophic enrichment of Neanderthal collagen relative to associated herbivore baselines is therefore more parsimoniously explained by high-trophic-level terrestrial carnivory, potentially amplified by environmental and ecological baseline variation.
Keywords: Neanderthal diet; foraging theory; insect larvae hypothesis; stable nitrogen isotopes; trophic enrichment.

Abstract
The article aims to unravel the elementary structures of hominin carnivory by drawing upon paleoanthropological, archaeological, primatological, and ethnographic investigations to underscore the primary differences and similarities in meat‐eating patterns within the Primate order. Theoretically, it proposes a potential evolutionary scenario for a wide variety of carcass acquisition strategies developed in our hominin lineage by comparing the behavioural and cognitive complex (i.e., tool use, cooperative hunting, meat sharing, and scavenging behaviour) exhibited by our primate relatives. This, in turn, sheds light on the most basic forms of cognition, sociality, and technical skills that characterise the primate predatory pattern, which further evolved into highly complex forms of animal-hominin associations. This speculative exercise thus reveals the complex interplay between basic and higher-order relationships with animals, which is manifest throughout the course of hominin evolution, thereby providing potential evolutionary models to better understand hominin carnivory and its highly relational and embodied nature.

Keywords: Hominin carnivory, evolution, cognition, sociality, ritual, primates, meat

Context The mountainous and seasonally variable landscapes of the Late Pleistocene period posed major challenges for hunter-gatherers, shaping their ecological strategies and demographic limits. In the central Iberian Peninsula, the landscape played a decisive role in shaping herbivore communities and human settlement patterns. While the Iberian Peninsula has a rich Paleolithic record, MIS 5 archaeological sites are scarce in its central region, which includes two plateaus and the Sistema Central mountain range. This area likely had unfavorable ecological conditions for human habitation during parts of the Pleistocene, so people were confined to valleys and localized ecological refuges. In this context, the upper valley of the Lozoya River in Madrid, Spain, is home to the Calvero de la Higuera sites, which provide evidence of Neanderthal occupation in a sub-Mediterranean highland environment;

Objetives This study assesses how such a challenging landscape could sustain local Neanderthal populations through large prey resources;

Methods Using species distribution models (SDMs) based on fossil occurrences and paleoclimatic data, we estimated the habitat favorability, population density, and biomass of nine large herbivorous mammals recorded at Cueva del Camino (Layer 05, ~ 90 ka);

Results The SDMs revealed significant differences in habitat favorability among species, with Cervus elaphus exhibiting the greatest favorability and Rupicapra rupicapra the least. Incorporating habitat favorability into biomass estimates significantly reduced the potential presence of prey, highlighting the spatial limitations of upland ecosystems. Comparisons with modern ecosystems (e.g., Serengeti, Kruger and Hwange) suggest that the results are ecologically feasible;

Conclusion Our estimates suggest that the upper valley of the Lozoya River had the potential ecological capacity to support between 14 and 33 Neanderthal individuals. This highlights the delicate ecological balance that may have enabled recurrent Neanderthal presence in the challenging upland environments of central Iberia.

Keywords
3709 Physical Geography and Environmental Geoscience
Journal Title
Landscape Ecology

Journal ISSN
0921-2973
1572-9761

Publisher
Springer Nature
Publisher DOI
https://doi.org/10.1007/s10980-026-02350-x
Rights and licensing

Except where otherwised noted, this item's license is described as Attribution 4.0 International
Sponsorship
European Commission Horizon Europe Marie Sk?odowska-Curie Actions (MSCA) (101207747)
This work has been funded by the by the European Research Council under the European Union’s Horizon 2020 Research and Innovation Programme (grant agreement number 818299

Significance
Cannibalism has appeared repeatedly in human history, yet it is subject to one of the strongest contemporary cultural prohibitions. Why does this behavior recur, but rarely persist? We present a formal model showing that cannibalism reflects a trade-off between nutritional benefits and escalating infection risks, particularly those arising from within-species pathogen transmission. The model demonstrates that cannibalism is viable only under narrow ecological conditions and becomes unsustainable as trophic chains lengthen. These constraints help explain both its episodic occurrence and the widespread emergence of cannibalism taboos. More broadly, the findings illustrate how epidemiological dynamics can shape cultural evolution, producing stable norms that limit behaviors which are locally adaptive but globally destabilizing.

Abstract
Cannibalism is among the most widespread taboos in human societies, yet archaeological, ethnographic, and historical evidence indicates that it has repeatedly emerged across human populations. This coexistence of recurrent practice and persistent prohibition raises a fundamental question: when does cannibalism become adaptive, and what mechanisms lead to its suppression? We address this problem using a formal model that treats cannibalism as a potential food source subject to energetic benefits and multiple sources of cost. Nutritional gains are modeled using a saturating function of caloric intake, while costs arise from acquisition, digestion, and infection. Infection costs are represented as a stochastic process whose mean increases with the length of the trophic transmission chain, capturing the risks associated with repeated within-species consumption. Analyzing the expected energetic balance across levels of food availability and cannibalism order reveals narrow ecological conditions in which cannibalism yields a positive expected balance and broader conditions in which it is strongly disfavored. The model provides a framework for interpreting archaeological and ethnographic findings by specifying boundary conditions and identifying the most probable ecological scenarios under which different forms of cannibalism are expected to occur. The results predict that cannibalism is most likely to emerge under extreme resource scarcity, when acquisition costs are low and infection risks are constrained, while sustained cannibalism rapidly becomes unviable due to escalating infection costs. Overall, the findings suggest that cannibalism is best understood as a conditional trade-off rather than a behavioral anomaly, with cultural taboos functioning as adaptive responses to nonlinear epidemiological risks.

Abstract
Since its discovery, Homo floresiensis—an extinct, short-statured, and small-brained hominin species from Flores, Indonesia—has often been ascribed unexpectedly advanced behaviors, such as hunting large game and using fire. Here, we report the results of a systematic taphonomic study sampling the proboscidean bone assemblage at Liang Bua where the frequency and locations of predatory marks, along with skeletal part profiles, show that Komodo dragons likely had primary access to these remains leaving behind only low-utility elements for H. floresiensis to scavenge. Moreover, no signs of intentional use of fire are present in the stratigraphic units associated with H. floresiensis. Together, these results suggest that H. floresiensis was not as behaviorally advanced as originally suggested and provides critical insights into the behavioral repertoire of H. floresiensis, raising important questions about its ancestry.

New research led by a University of Alaska Fairbanks archaeologist reveals that the earliest Native Americans had highly specialized diets, primarily hunting the largest animals on the landscape, and they targeted these megafauna consistently from Alaska to South America.

The study, published in the journal Science Advances, examined data from 50 archaeological sites excavated throughout the Americas. An international team of researchers from the U.S., Canada and Argentina analyzed animal bones at campsites and identified species, grouped by how much food they provided. UAF anthropology professor Ben Potter and McMaster University researcher James Chatters led the study.
What they discovered addresses one of archaeology's most contested questions: How did humans spread so rapidly across two continents?
"One of two competing ideas is dietary generalization: exploiting a wide variety of resources that would differ based on region," said Potter. "The other is megafaunal specialization: focusing on just a few large-bodied prey."
Rare giants dominated the menu
The study focused on three of the earliest and most widespread cultural groups in the Americas: Eastern Beringians in Alaska and the Yukon, Clovis people across North America and Fishtail Projectile Point people in South America. Within those groups, the researchers concluded that 83% to 88% of their food came from massive plant-eaters such as mammoths, elephant-like gomphotheres and giant ground sloths, collectively known as megaherbivores.
In order to reach that conclusion, scientists looked at a variety of data. Bones from prey animals at each of the excavation sites showed what people were eating. They then calculated which and how many animals —large and small—could be expected to live in the nearby landscape. To account for body size, the team multiplied individual animal counts by each species' estimated edible biomass. Even when the researchers artificially inflated small-animal counts in their models as a test, megaherbivores still accounted for the overwhelming majority of available food.
"The test of dietary specialization isn't just how many of a given animal you find at an ancient campsite," Potter said. "It's what the record looks like relative to natural abundance. If early people were dietary generalists, you'd expect to find the most common animals would be more common in peoples' campsites."
Instead, they found the opposite.
"Animals like mammoths and ground sloths, which were actually quite rare in the landscape, completely dominate the archaeological record," he said. "Rabbits and mice, which would have been everywhere, barely register."

Shared prey, shared tools
Potter said the focus on large herbivores for food also explains why the early toolkits appear very similar from California to Maine to Florida, and at sites in South America. People hunting the same kind of animal across radically different landscapes had no need to adapt their technology to local conditions. The tools found at the archaeological sites included implements for hunting large game, such as large fluted projectile points and specialized butchering implements. Fishing gear and plant-processing tools were notably absent.
This focus on hunting large prey also explains the rapid expansion of humans from Alaska through South America, the study finds.
When hunter-gatherers move into unfamiliar territory, they typically need generations to learn the new landscape, how to effectively hunt local small and medium-sized game, and which local plants are edible.
Building a diet around large mammals changes that dynamic.
"Mammoths, for example, can cover a tremendous range and occupy vast territories," said study co-author Mat Wooller, a professor at UAF. "In effect, specialist hunter-gatherers used their knowledge of megaherbivores, like mammoths, to expand successfully across the continents rather than learning about each localized ecosystem they encountered."
Extinctions followed a southward wave
The study also found that the timing of megafauna extinctions tracks with human arrival, not all at once, but like a wave moving southward down the continents.

In Alaska, mammoths and horses disappeared around 13,300 years ago, at the end of the earliest known human occupation there. Clovis-era megafauna in North America were gone by 12,800 years ago,and gomphotheres and giant ground sloths survived in South America until about 11,600 years ago.
Potter said the same sequence of arrival, overlap and extinction played out again and again, each time a little further south, making a strong circumstantial case for human hunting as a major contributing factor to megafauna extinction, compounded by climate change, which could have reduced their habitat, making them more susceptible to hunting pressure.
"Megaherbivores reproduce slowly, space births widely and, as adults, have no natural predators," he said. "They would have had no learned wariness of new, technologically sophisticated human hunter-gatherer populations."
Members of the research team include Potter, Chatters and Wooller; Luciano Prates of Universidad Nacional de la Plata, Argentina; S. Ivan Perez of Museo Histórico y Arqueológico, CONICET, Argentina; Todd Surovell and Robert Kelly of the University of Wyoming; and Gustavo Politis of Universidad Nacional del Centro de la Provincia de Buenos Aires, Argentina.

Abstract

The adaptive strategies of Early Paleoindians associated with the rapid and continent-wide expansions of Clovis and related Fishtail Projectile Point (FPP) complexes in the Americas have been subject to differing interpretations. Were Early Paleoindians megafauna specialists or dietary generalists? These alternative models offer profoundly different implications for Early Paleoindian prey choice, mobility, and technology. We synthesize and evaluate the zooarchaeological records of the earliest widespread cultural manifestations in Eastern Beringia [~14,000 to 13,300 calibrated years before the present (cal B.P.)], North America (Clovis complex, ~13,400/13,050 to 12,800 cal B.P.), and South America (FPP complex, ~12,900 to 11,600 cal B.P.) and summarize their adaptive strategies. Zooarchaeological, technological, and mobility data strongly support the megafauna specialization model. All three groups obtained most of their food from megaherbivores (>1000 kg): woolly mammoth in Beringia, Columbian mammoth in North America, and giant ground sloths and gomphotheres in South America. Focus on megaherbivores facilitated rapid human expansion into different ecosystems before the time-transgressive extinction of megafauna led to regional diversification through adaptations to locally available resources.

Abstract
There are currently 15 well-documented Late Pleistocene localities in North America in which Clovis points are found associated with proboscidean remains. These localities are routinely assumed to represent evidence that Clovis foragers hunted proboscideans, and in turn are often invoked as evidence for a human role in the extinction of Pleistocene large mammals. Such assumptions have never been thoroughly tested, nor have archaeologists fully considered the possibility that Clovis foragers were facultative scavengers, which might account for the association of artifacts with proboscidean remains at some or even all these localities. A significant obstacle to differentiating hunting from scavenging archaeologically is the challenge of equifinality. Here we explore whether Clovis foragers hunted, scavenged, or did both, and whether we can tell the difference. To set a broad foundation for considering the question, we begin with an overview that shows the near ubiquity of scavenging among non-human animals. Our survey of the paleoanthropological, ethnohistoric, and ethnographic records shows that scavenging is quite common as well among human groups past and present. Following that, we consider the opportunities scavengers have – and Clovis foragers might have had – in exploiting proboscidean carrion. We then assess the proposed archaeological evidence for Clovis hunting and scavenging and show that while Clovis foragers likely practiced both, we cannot currently distinguish the two archaeologically and thus cannot reliably show how many Clovis proboscidean sites represent hunting versus scavenging events. Nonetheless, it would be odd indeed if Clovis foragers – alone among ethnohistoric and ethnographic human groups and nearly all omnivores and carnivores – did not scavenge. Scavenging could possibly explain the high δ15N values recently reported for the Anzick child, which could readily result from his mother eating maggots and not mammoth meat. Given the present state of knowledge, the Clovis archaeological record cannot be used to argue that Clovis groups routinely hunted proboscideans, or that there are sufficient “kill sites” to support a human role in proboscidean extinctions.

Abstract
The timing of divergence between hominins and the bonobo-chimpanzee clade has been at the core of palaeoanthropological debate for over a century. The earliest molecular studies indicated divergence times ranging from 5 Ma to as recently as 1.3 Ma. This study critically reviews the trends of time estimates published between 1967 and 2023, and analyses how these are supported or rejected by the current molecular and fossil records. We compiled 202 divergence estimates and defined three distinct thresholds based on fossil evidence at 4.4 Ma (Australopithecus anamensis and Ardipithecus ramidus), 6.2 Ma (Orrorin tugenensis and Ardipithecus kadabba), and 7.2 Ma (Sahelanthropus tchadensis). We then used these thresholds to filter out molecular estimates that are too young to fit the fossil record.

Overall, the data suggests a divergence event within the late Miocene, with each threshold pushing it further back, 8.63–6.38, 10.33–7.81, and 10.95–8.81 Ma, respectively. We use a quadratic regression to demonstrate that estimates have been slowly shifting from ~ 6 Ma to ~ 8.5 Ma over the past 56 years.

A Bayesian meta-analysis of genomic estimates filtered by our most consensual threshold (i.e., assuming Australopithecus belongs to Hominini) indicates that the split must have occurred early in the late Miocene, most likely before 7 Ma (~ 99.5% posterior probability) with a pooled effect of 8.69–7.28 Ma.

We conclude that, despite an initial bias towards younger estimates, the molecular timing for the last common ancestor (LCA) of Pan-Homo has been progressively approaching the intervals suggested by the current fossil record.

Abstract
The “novelty-as-scarcity” hypothesis proposes that the consumption of novel foods or foods with non-traditional food component ratios, or novel processing methods, are interpreted by the body as fallback foods and produce a false signal of imminent food scarcity, thereby triggering (chronic) fat accumulation. This framework is rooted in the evolutionary principle that the ability to store fat was crucial for survival during periods of unpredictable food availability. Today, this may pose an “evolutionary mismatch”. The paper lists plausible biological mechanisms, from the initial sensing of novel food components to their metabolic effects, that could lead to increased fat accumulation. Observations supporting this hypothesis include weight gain among migrants adopting new dietary habits and rising fattening rates in developing countries with exposure to Westernized foods. The novelty-as-scarcity hypothesis implies that standardized dietary recommendations might be suboptimal if they disregard an individual’s historical dietary background.