The earliest unequivocally modern humans in southern China

Edge chipping patterns in posterior teeth of hominins and apes

Chip scars in fossil teeth are a lasting evidence that bears on human evolution. Chip dimensions in posterior teeth of hominins, apes and white-lipped peccary (Tayassu pecari) are measured from published occlusal images. The results are plotted as D/Dm vs. h/Dm, where h, D and Dm denote indent distance, chip width and mean tooth crown diameter. The hominin species follow a similar pattern where D/Dm monotonically increases up to h/Dm ≈ 0.3. The behavior for the apes is characterized by two phases. In the first, h/Dm monotonically increases up to h/Dm ≈ 0.26 while in the second (h/Dm ≈ 0.26 to 0.42), D/Dm experiences a drastic change in behavior. The interpretation of chip morphology is assisted by results from controlled spherical indentation tests on extracted human molars. This study shows that in addition to the commonly recognized chipping due to cusp loading, a chip may also initiate from the inner wall of the tooth's central fossa. Accordingly, it is suggested that the chipping in hominins generally initiates from a (worn) cusp while that in apes involves cusp loading up to h/Dm ≈ 0.26 and fossa loading thereafter. The behavior for T. pecari is much similar to that of the apes. The fossa chipping is facilitated by a consumption of hard, large-size diet (e.g., plants, roots, barks and nuts) and presence of broad central fossa, conditions that are met in apes. Finally, a simple expression for the critical chipping force Pch due to fossa loading is developed.

Identification and Construction of a Disulfidptosis-Mediated Diagnostic Model and Associated Immune Microenvironment of Osteoarthritis from the Perspective of PPPM

Background

Osteoarthritis (OA) is a major cause of human disability. Despite receiving treatment, patients with the middle and late stage of OA have poor survival outcomes. Therefore, within the framework of predictive, preventive, and personalized medicine (PPPM/3PM), early personalized diagnosis of OA is particularly prominent. PPPM aims to accurately identify disease by integrating multiple omic techniques; however, the efficiency of currently available methods and biomarkers in predicting and diagnosing OA should be improved. Disulfidptosis, a novel programmed cell death mechanism and appeared in particular metabolic status, plays a mysterious characteristic in the occurrence and development of OA, which warrants further investigation.

Methods

In this study, we integrated three public datasets from the Gene Expression Omnibus (GEO) database, including 26 OA samples and 20 normal samples. Via a series of bioinformatic analysis and machine learning, we identified the diagnostic biomarkers and several subtypes of OA. Moreover, the expression of these biomarkers were verified in our in-house cohort and the single cell dataset.

Results

Three significant regulators of disulfidptosis (NCKAP1, OXSM, and SLC3A2) were identified through differential expression analysis and machine learning. And a nomogram constructed based on these three regulators exhibited ideal efficiency in predicting early- and late-stage OA. Furthermore, based on the expression of three regulators, we identified two disulfidptosis-related subtypes of OA with different infiltration of immune cells and personalized expression level of immune checkpoints. Notably, the expression of the three regulators was demonstrated in a single-cell RNA profile and verified in the synovial tissue in our in-house cohort including 6 OA patients and 6 normal people. Finally, an efficient disulfidptosis-mediated diagnostic model was constructed for OA, with the AUC value of 97.6923% in the training set and 93.3333% and 100% in two validation sets.

Conclusion

Overall, with regard to PPPM, this study provided novel insights into the role of disulfidptosis regulators in the personalized diagnosis and treatment of OA.

Environmental conditions associated with initial northern expansion of anatomically modern humans

The ability of our ancestors to switch food sources and to migrate to more favourable environments enabled the rapid global expansion of anatomically modern humans beyond Africa as early as 120,000 years ago. Whether this versatility was largely the result of environmentally determined processes or was instead dominated by cultural drivers, social structures, and interactions among different groups, is unclear. We develop a statistical approach that combines both archaeological and genetic data to infer the more-likely initial expansion routes in northern Eurasia and the Americas. We then quantify the main differences in past environmental conditions between the more-likely routes and other potential (less-likely) routes of expansion. We establish that, even though cultural drivers remain plausible at finer scales, the emergent migration corridors were predominantly constrained by a combination of regional environmental conditions, including the presence of a forest-grassland ecotone, changes in temperature and precipitation, and proximity to rivers.

Ghosts of extinct apes: genomic insights into African hominid evolution

We are accustomed to regular announcements of new hominin fossils. There are now some 6000 hominin fossils, and up to 31 species. However, where are the announcements of African ape fossils? The answer is that there are almost none. Our knowledge of African ape evolution is based entirely on genomic analyses, which show that extant diversity is very young. This contrasts with the extensive and deep diversity of hominins known from fossils. Does this difference point to low and late diversification of ape lineages, or high rates of extinction? The comparative evolutionary dynamics of African hominids are central to interpreting living ape adaptations, as well as understanding the patterns of hominin evolution and the nature of the last common ancestor.

New Late Pleistocene age for the Homo sapiens skeleton from Liujiang southern China

The emergence of Homo sapiens in Eastern Asia is a topic of significant research interest. However, well-preserved human fossils in secure, dateable contexts in this region are extremely rare, and often the subject of intense debate owing to stratigraphic and geochronological problems. Tongtianyan cave, in Liujiang District of Liuzhou City, southern China is one of the most important fossils finds of H. sapiens, though its age has been debated, with chronometric dates ranging from the late Middle Pleistocene to the early Late Pleistocene. Here we provide new age estimates and revised provenience information for the Liujiang human fossils, which represent one of the most complete fossil skeletons of H. sapiens in China. U-series dating on the human fossils and radiocarbon and optically stimulated luminescence dating on the fossil-bearing sediments provided ages ranging from ~33,000 to 23,000 years ago (ka). The revised age estimates correspond with the dates of other human fossils in northern China, at Tianyuan Cave (~40.8-38.1 ka) and Zhoukoudian Upper Cave (39.0-36.3 ka), indicating the geographically widespread presence of H. sapiens across Eastern Asia in the Late Pleistocene, which is significant for better understanding human dispersals and adaptations in the region.

Hunter-gatherer genetics research: Importance and avenues

Major developments in the field of genetics in the past few decades have revolutionised notions of what it means to be human. Although currently only a few populations around the world practise a hunting and gathering lifestyle, this mode of subsistence has characterised members of our species since its very origins and allowed us to migrate across the planet. Therefore, the geographical distribution of hunter-gatherer populations, dependence on local ecosystems and connections to past populations and neighbouring groups have provided unique insights into our evolutionary origins. However, given the vulnerable status of hunter-gatherers worldwide, the development of the field of anthropological genetics requires that we reevaluate how we conduct research with these communities. Here, we review how the inclusion of hunter-gatherer populations in genetics studies has advanced our understanding of human origins, ancient population migrations and interactions as well as phenotypic adaptations and adaptability to different environments, and the important scientific and medical applications of these advancements. At the same time, we highlight the necessity to address yet unresolved questions and identify areas in which the field may benefit from improvements.

Concurrent Asian monsoon strengthening and early modern human dispersal to East Asia during the last interglacial

The relationship between initial Homo sapiens dispersal from Africa to East Asia and the orbitally paced evolution of the Asian summer monsoon (ASM)-currently the largest monsoon system-remains underexplored due to lack of coordinated synthesis of both Asian paleoanthropological and paleoclimatic data. Here, we investigate orbital-scale ASM dynamics during the last 280 thousand years (kyr) and their likely influences on early H. sapiens dispersal to East Asia, through a unique integration of i) new centennial-resolution ASM records from the Chinese Loess Plateau, ii) model-based East Asian hydroclimatic reconstructions, iii) paleoanthropological data compilations, and iv) global H. sapiens habitat suitability simulations. Our combined proxy- and model-based reconstructions suggest that ASM precipitation responded to a combination of Northern Hemisphere ice volume, greenhouse gas, and regional summer insolation forcing, with cooccurring primary orbital cycles of ~100-kyr, 41-kyr, and ~20-kyr. Between ~125 and 70 kyr ago, summer monsoon rains and temperatures increased in vast areas across Asia. This episode coincides with the earliest H. sapiens fossil occurrence at multiple localities in East Asia. Following the transcontinental increase in simulated habitat suitability, we suggest that ASM strengthening together with Southeast African climate deterioration may have promoted the initial H. sapiens dispersal from their African homeland to remote East Asia during the last interglacial.

Climate amelioration, abrupt vegetation recovery, and the dispersal of Homo sapiens in Baikal Siberia

The dispersal of Homo sapiens in Siberia and Mongolia occurred by 45 to 40 thousand years (ka) ago; however, the climatic and environmental context of this event remains poorly understood. We reconstruct a detailed vegetation history for the Last Glacial period based on pollen spectra from Lake Baikal. While herb and shrub taxa including Artemisia and Alnus dominated throughout most of this period, coniferous forests rapidly expanded during Dansgaard-Oeschger (D-O) events 14 (55 ka ago) and 12 to 10 (48 to 41 ka ago), with the latter presenting the strongest signal for coniferous forest expansion and Picea trees, indicating remarkably humid conditions. These abrupt forestation events are consistent with obliquity maxima, so that we interpret last glacial vegetation changes in southern Siberia as being driven by obliquity change. Likewise, we posit that major climate amelioration and pronounced forestation precipitated H. sapiens dispersal into Baikal Siberia 45 ka ago, as chronicled by the appearance of the Initial Upper Paleolithic.

Morphological and morphometric analyses of a late Middle Pleistocene hominin mandible from Hualongdong, China

Excavations in Hualongdong (HLD), East China, have yielded abundant hominin fossils dated to 300 ka. There is a nearly complete mandible that fits well with a partial cranium, and together they compose the skull labeled as HLD 6. Thus far, detailed morphological description and comparisons of the mandible have not been conducted. Here we present a comprehensive morphological, metric, and geometric morphometric assessment of this mandible and compare it with both adult and immature specimens of Pleistocene hominins and recent modern humans. Results indicate that the HLD 6 mandible exhibits a mosaic morphological pattern characterized by a robust corpus and relatively gracile symphysis and ramus. The moderately developed mental trigone and a clear anterior mandibular incurvation of the HLD 6 mandible are reminiscent of Late Pleistocene hominin and recent modern human morphology. However, the weak expression of all these features indicates that this mandible does not possess a true chin. Moreover, a suite of archaic features that resemble those of Middle Pleistocene hominins includes pronounced alveolar planum, superior transverse torus, thick corpus, a pronounced endocondyloid crest, and a well-developed medial pterygoid tubercle. The geometric morphometric analysis further confirms the mosaic pattern of the HLD 6 mandible. The combination of both archaic and modern human features identified in the HLD 6 mandible is unexpected, given its late Middle Pleistocene age and differs from approximately contemporaneous Homo members such as Xujiayao, Penghu, and Xiahe. This mosaic pattern has never been recorded in late Middle Pleistocene hominin fossil assemblages in East Asia. The HLD 6 mandible provides further support for the high morphological diversity during late Middle Pleistocene hominin evolution. With these findings, it is possible that modern human morphologies are present as early as 300 ka and earlier than the emergence of modern humans in East Asia.

Early presence of Homo sapiens in Southeast Asia by 86-68 kyr at Tam Pà Ling, Northern Laos

The timing of the first arrival of Homo sapiens in East Asia from Africa and the degree to which they interbred with or replaced local archaic populations is controversial. Previous discoveries from Tam Pà Ling cave (Laos) identified H. sapiens in Southeast Asia by at least 46 kyr. We report on a recently discovered frontal bone (TPL 6) and tibial fragment (TPL 7) found in the deepest layers of TPL. Bayesian modeling of luminescence dating of sediments and U-series and combined U-series-ESR dating of mammalian teeth reveals a depositional sequence spanning ~86 kyr. TPL 6 confirms the presence of H. sapiens by 70 ± 3 kyr, and TPL 7 extends this range to 77 ± 9 kyr, supporting an early dispersal of H. sapiens into Southeast Asia. Geometric morphometric analyses of TPL 6 suggest descent from a gracile immigrant population rather than evolution from or admixture with local archaic populations.

A new chronological framework for Chuandong Cave and its implications for the appearance of modern humans in southern China

Chuandong Cave is an important Late Paleolithic site because it documents the early appearance of bone tools in southern China. We used the single-aliquot regenerative-dose protocol for optically stimulated luminescence dating to improve the precision of the chronology for the Chuandong Cave sedimentary sequence. The age of each layer was determined using a Bayesian modeling approach which combined optically stimulated luminescence ages with published AMS ¹⁴C dates. The results showed that Layer 10 began accumulating since 56 ± 14 ka and provides the upper age limit for all artifacts from the sequence. Bone awl tools from Layer 8, the earliest grinding bone tools in this site, were recovered within sediments between 40 ± 7 ka and 30 ± 4 ka. Layer 8 also indicates the appearance of modern humans in the Chuandong Cave sequence. Layers 4-2, ranging from 15 ± 3 ka until 11 ± 1 ka and including the Younger Dryas period, contain a few bone awls and an eyed bone needle. The shift from bone awls to eyed bone needles in the Chuandong Cave sequence indicates that modern humans adapted to the changing climate of southern China. We conclude that modern human behavior in bone tools appeared in southern China as early as 40 ± 7 ka, became more sophisticated during the Last Glacial Maximum, and spread more widely across southern China during the Younger Dryas.

The evolution of human skin pigmentation: A changing medley of vitamins, genetic variability, and UV radiation during human expansion

This review examines putative, yet likely critical evolutionary pressures contributing to human skin pigmentation and subsequently, depigmentation phenotypes. To achieve this, it provides a synthesis of ideas that frame contemporary thinking, without limiting the narrative to pigmentation genes alone. It examines how geography and hence the quality and quantity of UV exposure, pigmentation genes, diet-related genes, vitamins, anti-oxidant nutrients, and cultural practices intersect and interact to facilitate the evolution of human skin color. The article has a strong focus on the vitamin D-folate evolutionary model, with updates on the latest biophysical research findings to support this paradigm. This model is examined within a broad canvas that takes human expansion out of Africa and genetic architecture into account. A thorough discourse on the biology of melanization is provided (includes relationship to BH4 and DNA damage repair), with the relevance of this to the UV sensitivity of folate and UV photosynthesis of vitamin D explained in detail, including the relevance of these vitamins to reproductive success. It explores whether we might be able to predict vitamin-related gene polymorphisms that pivot metabolism to the prevailing UVR exposome within the vitamin D-folate evolutionary hypothesis context. This is discussed in terms of a primary adaptive phenotype (pigmentation/depigmentation), a secondary adaptive phenotype (flexible metabolic phenotype based on vitamin-related gene polymorphism profile), and a tertiary adaptive strategy (dietary anti-oxidants to support the secondary adaptive phenotype). Finally, alternative evolutionary models for pigmentation are discussed, as are challenges to future research in this area.

Evolution of Homo in the Middle and Late Pleistocene

The Middle and Late Pleistocene is arguably the most interesting period in human evolution. This broad period witnessed the evolution of our own lineage, as well as that of our sister taxon, the Neanderthals, and related Denisovans. It is exceptionally rich in both fossil and archaeological remains, and uniquely benefits from insights gained through molecular approaches, such as paleogenetics and paleoproteomics, that are currently not widely applicable in earlier contexts. This wealth of information paints a highly complex picture, often described as 'the Muddle in the Middle,' defying the common adage that 'more evidence is needed' to resolve it. Here we review competing phylogenetic scenarios and the historical and theoretical developments that shaped our approaches to the fossil record, as well as some of the many remaining open questions associated with this period. We propose that advancing our understanding of this critical time requires more than the addition of data and will necessitate a major shift in our conceptual and theoretical framework.

Homo sapiens lithic technology and microlithization in the South Asian rainforest at Kitulgala Beli-lena (c. 45 - 8,000 years ago)

Recent archaeological investigations in Sri Lanka have reported evidence for the exploitation and settlement of tropical rainforests by Homo sapiens since c. 48,000 BP. Information on technological approaches used by human populations in rainforest habitats is restricted to two cave sites, Batadomba-lena and Fa-Hien Lena. Here, we provide detailed study of the lithic assemblages of Kitulgala Beli-lena, a recently excavated rockshelter preserving a sedimentary sequence from the Late Pleistocene to the Holocene. Our analysis indicates in situ lithic production and the recurrent use of the bipolar method for the production of microliths. Stone tool analyses demonstrate long-term technological stability from c. 45,000 to 8,000 years BP, a pattern documented in other rainforest locations. Foraging behaviour is characterised by the use of lithic bipolar by-products together with osseous projectile points for the consistent targeting of semi-arboreal/arboreal species, allowing for the widespread and recurrent settlement of the wet zone of Sri Lanka.

Diet of the earliest modern humans in East Asia

Reconstructing diet can offer an improved understanding toward the origin and evolution of modern humans. However, the diet of early modern humans in East Asia is poorly understood. Starch analysis of dental calculus is harmless to precious fossil hominins and provides the most direct evidence of plant food sources in early modern human dietary records. In this paper, we examined the starch grains in dental calculus from Fuyan Cave hominins in Daoxian (South China), which were the earliest modern humans in East Asia. Our results reveal the earliest direct evidence of a hominin diet made of acorns, roots, tubers, grass seeds, and other yet-unidentified plants in marine isotope stage 5 between 120 and 80 ka. Our study also provides the earliest evidence that acorns may have played an important role in subsistence strategies. There may have been a long-lasting tradition of using these plants during the Late Pleistocene in China. Plant foods would have been a plentiful source of carbohydrates that greatly increased energy availability to human tissues with high glucose demands. Our study provides the earliest direct consumption of carbohydrates-rich plant resources from modern humans in China for the first time. In addition, it also helps elucidate the evolutionary advantages of early modern humans in the late Middle and early Upper Pleistocene.

A Late Pleistocene human genome from Southwest China

Southern East Asia is the dispersal center regarding the prehistoric settlement and migrations of modern humans in Asia-Pacific regions. However, the settlement pattern and population structure of paleolithic humans in this region remain elusive, and ancient DNA can provide direct information. Here, we sequenced the genome of a Late Pleistocene hominin (MZR), dated ∼14.0 thousand years ago from Red Deer Cave located in Southwest China, which was previously reported possessing mosaic features of modern and archaic hominins. MZR is the first Late Pleistocene genome from southern East Asia. Our results indicate that MZR is a modern human who represents an early diversified lineage in East Asia. The mtDNA of MZR belongs to an extinct basal lineage of the M9 haplogroup, reflecting a rich matrilineal diversity in southern East Asia during the Late Pleistocene. Combined with the published data, we detected clear genetic stratification in ancient southern populations of East/Southeast Asia and some degree of south-versus-north divergency during the Late Pleistocene, and MZR was identified as a southern East Asian who exhibits genetic continuity to present day populations. Markedly, MZR is linked deeply to the East Asian ancestry that contributed to First Americans.

Tropical forests in the deep human past

Since Darwin, studies of human evolution have tended to give primacy to open 'savannah' environments as the ecological cradle of our lineage, with dense tropical forests cast as hostile, unfavourable frontiers. These perceptions continue to shape both the geographical context of fieldwork as well as dominant narratives concerning hominin evolution. This paradigm persists despite new, ground-breaking research highlighting the role of tropical forests in the human story. For example, novel research in Africa's rainforests has uncovered archaeological sites dating back into the Pleistocene; genetic studies have revealed very deep human roots in Central and West Africa and in the tropics of Asia and the Pacific; an unprecedented number of coexistent hominin species have now been documented, including Homo erectus, the 'Hobbit' (Homo floresiensis), Homo luzonensis, Denisovans, and Homo sapiens. Some of the earliest members of our own species to reach South Asia, Southeast Asia, Oceania and the tropical Americas have shown an unexpected rapidity in their adaptation to even some of the more 'extreme' tropical settings. This includes the early human manipulation of species and even habitats. This volume builds on these currently disparate threads and, for the first time, draws together a group of interdisciplinary, agenda-setting papers that firmly places a broader spectrum of tropical environments at the heart of the deep human past. This article is part of the theme issue 'Tropical forests in the deep human past'.

Speleological and environmental history of Lida Ajer cave, western Sumatra

Some of the earliest evidence for the presence of modern humans in rainforests has come from the fossil deposits of Lida Ajer in Sumatra. Two human teeth from this cave were estimated to be 73–63 thousand years old, which is significantly older than some estimates of modern human migration out of Africa based on genetic data. The deposits were interpreted as being associated with a rainforest environment based largely on the presence of abundant orangutan fossils. As well as the main fossil-bearing chamber, fossil-bearing passages are present below a sinkhole, although the relationship between the different fossil deposits has only been tenuously established. Here, we provide significant new sedimentological, geochronological and palaeoecological data aimed at reconstructing the speleological and environmental history of the cave and the clastic and fossil deposits therein. Our data suggest that the Lida Ajer fossils were deposited during Marine Isotope Stage 4, with fossils from the lower passages older than the main fossil chamber. Our use of stable carbon and oxygen isotope analyses of mammalian tooth enamel demonstrates that early humans probably occupied a closed-canopy forest very similar to those present in the region today, although the fossil orangutans may have occupied a slightly different niche.

This article is part of the theme issue ‘Tropical forests in the deep human past’.

Modern human incursion into Neanderthal territories 54,000 years ago at Mandrin, France

Determining the extent of overlap between modern humans and other hominins in Eurasia, such as Neanderthals and Denisovans, is fundamental to understanding the nature of their interactions and what led to the disappearance of archaic hominins. Apart from a possible sporadic pulse recorded in Greece during the Middle Pleistocene, the first settlements of modern humans in Europe have been constrained to ~45,000 to 43,000 years ago. Here, we report hominin fossils from Grotte Mandrin in France that reveal the earliest known presence of modern humans in Europe between 56,800 and 51,700 years ago. This early modern human incursion in the Rhône Valley is associated with technologies unknown in any industry of that age outside Africa or the Levant. Mandrin documents the first alternating occupation of Neanderthals and modern humans, with a modern human fossil and associated Neronian lithic industry found stratigraphically between layers containing Neanderthal remains associated with Mousterian industries.

Modern human teeth unearthed from below the ∼128,000-year-old level at Punung, Java: A case highlighting the problem of recent intrusion in cave sediments

The emergence of modern humans in the eastern edge of the Eurasian Continent is debated between two major models: early (∼130-70 ka) and late (∼50 ka) dispersal models. The former view is grounded mainly on the claims that several cave sites in Southeast Asia and southern China yielded modern human fossils of those early ages, but such reports have been disputed for the lack of direct dating of the human remains and insufficient documentation of stratigraphy and taphonomy. By tracing possible burial process and conducting direct dating for an early Late Pleistocene paleontological site of Punung III, East Java, we here report a case that demonstrates how unexpected intrusion of recent human remains into older stratigraphic levels could occur in cave sediments. This further highlights the need of direct dating and taphonomic assessment before accepting either model. We also emphasize that the state of fossilization of bones and teeth is a useful guide for initial screening of recent intrusion and should be reported particularly when direct dating is unavailable. Additionally, we provide a revised stratigraphy and faunal list of Punung III, a key site that defines the tropical rainforest Punung Fauna during the early Late Pleistocene of the region.

The impact of prehistoric human dispersals on the presence of tobacco-related oral cancer in Northeast India

BACKGROUND

Northeast (NE) India is a subject of debate for predicting its involvement in prehistoric anatomically modern human (AMH) dispersal. The unique lifestyle and genetic characteristics of native ethnic groups in this region are believed to be responsible for their susceptibility to tobacco-related oral cancer (TrOC). The present study assessed mitochondrial macro-haplogroup (mHG) diversity and TrOC susceptibility autosomal loci to evaluate the impact of prehistoric AMH dispersal on the present day's high TrOC prevalence in major NE Indian ethnics.

METHODS

We considered 175 unrelated individuals from 35 ethnic groups and previously published 374 sequences for sequencing-based assessment of mtDNA-based marker by subsequent analyses like haplogroup diversity, phylogenetic, genetic structure by AMOVA, and MDS, descriptive statistics of demographic parameters, and migration analysis. Besides, we selected prolonged tobacco-chewing 124 case-control individuals from similar ethnic backgrounds for genotyping 115 autosomal loci in Sequenom iPLEX MassARRAY™ platform and mined 1000genome data (n = 398) for consequent global admixture and ancestry-specific allele frequencies-based analyses.

RESULTS

Our mtDNA-based findings suggested that NE populations were distinct from other Indian populations, owing to the first wave of migration from ancient southern China (∼54kya) and two successive spatial expansion events at ∼45kya and ∼43kya. Consequently, it probably acted as another source for prehistoric AMH dispersal in N/NE Asia. Besides, the second wave of back-migration from SE Asia (∼40kya) probably replaced the mitochondrial footprints of survivors from the first migrants and introduced the TrOC susceptibility traits in this region. Afterward, the autosomal marker-based observations on the transition of the disease-associated admixture component 'K6' from SE Asia reconfirmed these results. Moreover, we also observed that the mitochondrial mHG 'R' is significantly associated with the risk of TrOC (OR > 9.5) in NE India. Furthermore, the possible onset of the phenotypic expression of those traits was predicted at ∼4kya, thus, contributing to present-day's TrOC prevalence.

CONCLUSIONS

This study reflects its uniqueness by revealing an updated AMH dispersal route for the peopling in and out of NE India, which probably introduced the disease-causing traits in the ancestral NE Indian population. Those traits were then imprinted in their genome to get transferred through their respective generations, forming the present-day's TrOC-prevalent NE Indian population.

Dental caries in wild primates: Interproximal cavities on anterior teeth

Dental caries has been reported in a variety of primates, although it is still considered rare in wild populations. In this study, 11 catarrhine primate taxa (n = 339 individuals; 7946 teeth) were studied for the presence of caries. A differential diagnosis of lesions in interproximal regions of anterior teeth was undertaken, since they had been previously described as both carious and non-carious in origin. Each permanent tooth was examined macroscopically, with severity and position of lesions recorded. Two specimens were examined further, using micro-CT scans to assess demineralization. Differential diagnosis confirmed the cariogenic nature of interproximal cavities on anterior teeth (ICATs). Overall results show 3.3% of all teeth (i.e., anterior and posterior teeth combined) were carious (n = 262), with prevalence varying among species from 0% to >7% of teeth affected. Those with the highest prevalence of ICATs include Pan troglodytes verus (9.8% of anterior teeth), Gorilla gorilla gorilla (2.6%), Cercopithecus denti (22.4%), Presbytis femoralis (19.5%), and Cercopithecus mitis (18.3%). ICATs make up 87.9% of carious lesions on anterior teeth. These results likely reflect dietary and food processing differences among species, but also between the sexes (e.g., 9.3% of all female P. troglodytes verus teeth were carious vs. 1.8% in males). Processing cariogenic fruits and seeds with the anterior dentition (e.g., wadging) likely contributes to ICAT formation. Further research is needed in living primate populations to ascertain behavioral/dietary influences on caries occurrence. Given the presence of ICATs in frugivorous primates, their diagnosis in archaeological and paleontological specimens may shed light on diet and food processing behaviors in fossil primates.

Zhoukoudian Upper Cave personal ornaments and ochre: Rediscovery and reevaluation

Personal ornaments have become a key cultural proxy to investigate cognitive evolution, modern human dispersal, and population dynamics. Here, we reassess personal ornaments found at Zhoukoudian Upper Cave and compare them with those from other Late Paleolithic Northern Chinese sites. We reappraise the information provided by Pei Wen Chung on Upper Cave personal ornaments lost during World War II and analyze casts of 17 of them, along with two unpublished objects displayed at the Zhoukoudian Site Museum and three original perforated teeth rediscovered at the Zhoukoudian Site Museum. We apply archeozoological, technological and use-wear analyses to document variation in ornamental practices and their change throughout the site stratigraphy. Badger, fox, red deer, sika deer, marten, and tiger teeth as well as carp bone, bird bone, Anadara shell, limestone beads, and perforated pebble appear to have been the preferred objects used as ornaments by Upper Cave visitors. Multivariate analysis of technological data highlights a correspondence between cultural layers and perforation techniques, with radial incising being typical of layer L2 and bidirectional incising of L4. The three rediscovered badger canines display features suggesting they were sewed on clothing rather than suspended from necklaces or bracelets. Elemental scanning electron microscopy coupled with energy dispersive X-ray spectromety and mineralogical (μ-Raman) analyses of red residues adhering to the rediscovered teeth indicate these objects were originally coated with ochre and identify variations that match differences in technology. The two ornaments exhibited at the Zhoukoudian Site Museum are ancient teeth that were recently perforated and should be excluded from the Upper Cave assemblage. A seriation of Late Paleolithic ornaments found at Northern Chinese sites identifies a clear-cut difference in preferred ornament types between western and eastern sites, interpreted as reflecting two long-lasting traditions in garment symbolic codes.

Revisiting the out of Africa event with a deep-learning approach

Anatomically modern humans evolved around 300 thousand years ago in Africa. They started to appear in the fossil record outside of Africa as early as 100 thousand years ago, although other hominins existed throughout Eurasia much earlier. Recently, several studies argued in favor of a single out of Africa event for modern humans on the basis of whole-genome sequence analyses. However, the single out of Africa model is in contrast with some of the findings from fossil records, which support two out of Africa events, and uniparental data, which propose a back to Africa movement. Here, we used a deep-learning approach coupled with approximate Bayesian computation and sequential Monte Carlo to revisit these hypotheses from the whole-genome sequence perspective. Our results support the back to Africa model over other alternatives. We estimated that there are two sequential separations between Africa and out of African populations happening around 60-90 thousand years ago and separated by 13-15 thousand years. One of the populations resulting from the more recent split has replaced the older West African population to a large extent, while the other one has founded the out of Africa populations.

Human Evolution in Asia: Taking Stock and Looking Forward

We review the state of paleoanthropology research in Asia. We survey the fossil record, articulate the current understanding, and delineate the points of contention. Although Asia received less attention than Europe and Africa did in the second half of the twentieth century, an increase in reliably dated fossil materials and the advances in genetics have fueled new research. The long and complex evolutionary history of humans in Asia throughout the Pleistocene can be explained by a balance of mechanisms, between gene flow among different populations and continuity of regional ancestry. This pattern is reflected in fossil morphology and paleogenomics. Critical understanding of the sociocultural forces that shaped the history of hominin fossil research in Asia is important in charting the way forward.

Morphological description and evolutionary significance of 300 ka hominin facial bones from Hualongdong, China

Late Middle Pleistocene hominins in Africa displaying key modern morphologies by 315 ka are claimed as the earliest Homo sapiens. Evolutionary relationships among East Asian hominins appear complex due to a growing fossil record of late Middle Pleistocene hominins from the region, reflecting mosaic morphologies that contribute to a lack of consensus on when and how the transition to modern humans transpired. Newly discovered 300 ka hominin fossils from Hualongdong, China, provide further evidence to clarify these relationships in the region. In this study, facial morphology of the juvenile partial cranium (HLD 6) is described and qualitatively and quantitatively compared with that of other key Early, Middle, and Late Pleistocene hominins from East Asia, Africa, West Asia, and Europe and with a sample of modern humans. Qualitatively, facial morphology of HLD 6 resembles that of Early and Middle Pleistocene hominins from Zhoukoudian, Nanjing, Dali, and Jinniushan in China, as well as others from Java, Africa, and Europe in some of these features (e.g., supraorbital and malar regions), and Late Pleistocene hominins and modern humans from East Asia, Africa, and Europe in other features (e.g., weak prognathism, flat face and features in nasal and hard plate regions). Comparisons of HLD 6 measurements to group means and multivariate analyses support close affinities of HLD 6 to Late Pleistocene hominins and modern humans. Expression of a mosaic morphological pattern in the HLD 6 facial skeleton further complicates evolutionary interpretations of regional morphological diversity in East Asia. The prevalence of modern features in HLD 6 suggests that the hominin population to which HLD 6 belonged may represent the earliest pre-modern humans in East Asia. Thus, the transition from archaic to modern morphology in East Asian hominins may have occurred at least by 300 ka, which is 80,000 to 100,000 years earlier than previously recognized.

Skeletal remains of a Pleistocene modern human (Homo sapiens) from Sulawesi

Major gaps remain in our knowledge of the early history of Homo sapiens in Wallacea. By 70-60 thousand years ago (ka), modern humans appear to have entered this distinct biogeographical zone between continental Asia and Australia. Despite this, there are relatively few Late Pleistocene sites attributed to our species in Wallacea. H. sapiens fossil remains are also rare. Previously, only one island in Wallacea (Alor in the southeastern part of the archipelago) had yielded skeletal evidence for pre-Holocene modern humans. Here we report on the first Pleistocene human skeletal remains from the largest Wallacean island, Sulawesi. The recovered elements consist of a nearly complete palate and frontal process of a modern human right maxilla excavated from Leang Bulu Bettue in the southwestern peninsula of the island. Dated by several different methods to between 25 and 16 ka, the maxilla belongs to an elderly individual of unknown age and sex, with small teeth (only M1 to M3 are extant) that exhibit severe occlusal wear and related dental pathologies. The dental wear pattern is unusual. This fragmentary specimen, though largely undiagnostic with regards to morphological affinity, provides the only direct insight we currently have from the fossil record into the identity of the Late Pleistocene people of Sulawesi.

Climatic windows for human migration out of Africa in the past 300,000 years

Whilst an African origin of modern humans is well established, the timings and routes of their expansions into Eurasia are the subject of heated debate, due to the scarcity of fossils and the lack of suitably old ancient DNA. Here, we use high-resolution palaeoclimate reconstructions to estimate how difficult it would have been for humans in terms of rainfall availability to leave the African continent in the past 300k years. We then combine these results with an anthropologically and ecologically motivated estimate of the minimum level of rainfall required by hunter-gatherers to survive, allowing us to reconstruct when, and along which geographic paths, expansions out of Africa would have been climatically feasible. The estimated timings and routes of potential contact with Eurasia are compatible with archaeological and genetic evidence of human expansions out of Africa, highlighting the key role of palaeoclimate variability for modern human dispersals.

Ancient DNA and multimethod dating confirm the late arrival of anatomically modern humans in southern China

The expansion of anatomically modern humans (AMHs) from Africa around 65,000 to 45,000 y ago (ca. 65 to 45 ka) led to the establishment of present-day non-African populations. Some paleoanthropologists have argued that fossil discoveries from Huanglong, Zhiren, Luna, and Fuyan caves in southern China indicate one or more prior dispersals, perhaps as early as ca. 120 ka. We investigated the age of the human remains from three of these localities and two additional early AMH sites (Yangjiapo and Sanyou caves, Hubei) by combining ancient DNA (aDNA) analysis with a multimethod geological dating strategy. Although U-Th dating of capping flowstones suggested they lie within the range ca. 168 to 70 ka, analyses of aDNA and direct AMS ¹⁴C dating on human teeth from Fuyan and Yangjiapo caves showed they derive from the Holocene. OSL dating of sediments and AMS ¹⁴C analysis of mammal teeth and charcoal also demonstrated major discrepancies from the flowstone ages; the difference between them being an order of magnitude or more at most of these localities. Our work highlights the surprisingly complex depositional history recorded at these subtropical caves which involved one or more episodes of erosion and redeposition or intrusion as recently as the late Holocene. In light of our findings, the first appearance datum for AMHs in southern China should probably lie within the timeframe set by molecular data of ca. 50 to 45 ka.

Rare crested rat subfossils unveil Afro-Eurasian ecological corridors synchronous with early human dispersals

Biotic interactions between Africa and Eurasia across the Levant have invoked particular attention among scientists aiming to unravel early human dispersals. However, it remains unclear whether behavioral capacities enabled early modern humans to surpass the Saharo-Arabian deserts or if climatic changes triggered punctuated dispersals out of Africa. Here, we report an unusual subfossil assemblage discovered in a Judean Desert's cliff cave near the Dead Sea and dated to between ∼42,000 and at least 103,000 y ago. Paleogenomic and morphological comparisons indicate that the specimens belong to an extinct subspecies of the eastern African crested rat, Lophiomys imhausi maremortum subspecies nova, which diverged from the modern eastern African populations in the late Middle Pleistocene ∼226,000 to 165,000 y ago. The reported paleomitogenome is the oldest so far in the Levant, opening the door for future paleoDNA analyses in the region. Species distribution modeling points to the presence of continuous habitat corridors connecting eastern Africa with the Levant during the Last Interglacial ∼129,000 to 116,000 y ago, providing further evidence of the northern ingression of African biomes into Eurasia and reinforcing previous suggestions of the critical role of climate change in Late Pleistocene intercontinental biogeography. Furthermore, our study complements other paleoenvironmental proxies with local-instead of interregional-paleoenvironmental data, opening an unprecedented window into the Dead Sea rift paleolandscape.

How did modern morphology evolve in the human mandible? The relationship between static adult allometry and mandibular variability in Homo sapiens

Key to understanding human origins are early Homo sapiens fossils from Jebel Irhoud, as well as from the early Late Pleistocene sites Tabun, Border Cave, Klasies River Mouth, Skhul, and Qafzeh. While their upper facial shape falls within the recent human range of variation, their mandibles display a mosaic morphology. Here we quantify how mandibular shape covaries with mandible size and how static allometry differs between Neanderthals, early H. sapiens, and modern humans from the Upper Paleolithic/Later Stone Age and Holocene (= later H. sapiens). We use 3D (semi)landmark geometric morphometric methods to visualize allometric trends and to explore how gracilization affects the expression of diagnostic shape features. Early H. sapiens were highly variable in mandible size, exhibiting a unique allometric trajectory that explains aspects of their 'archaic' appearance. At the same time, early H. sapiens share a suite of diagnostic features with later H. sapiens that are not related to mandibular sizes, such as an incipient chin and an anteroposteriorly decreasing corpus height. The mandibular morphology, often referred to as 'modern', can partly be explained by gracilization owing to size reduction. Despite distinct static allometric shape changes in each group studied, bicondylar and bigonial breadth represent important structural constraints for the expression of shape features in most Middle to Late Pleistocene hominin mandibles.

Conceptual issues in hominin taxonomy: Homo heidelbergensis and an ethnobiological reframing of species

Efforts to name and classify Middle Pleistocene Homo, often referred to as "Homo heidelbergensis" are hampered by confusing patterns of morphology but also by conflicting paleoanthropological ideologies that are embedded in approaches to hominin taxonomy, nomenclature, and the species concept. We deconstruct these issues to show how the field's search for a "real" species relies on strict adherence to pre-Darwinian essentialist naming rules in a post-typological world. We then examine Middle Pleistocene Homo through the framework of ethnobiology, which examines on how Indigenous societies perceive, classify, and name biological organisms. This research reminds us that across human societies, taxonomies function to (1) identify and classify organisms based on consensus pattern recognition and (2) construct a stable nomenclature for effective storage, retrieval and communication of information. Naming Middle Pleistocene Homo as a "real" species cannot be verified with the current data; and separating regional groups into distinct evolutionary lineages creates taxa that are not defined by readily perceptible or universally salient differences. Based on ethnobiological studies of this kind of patterning, referring to these hominins above the level of the species according to their generic category with modifiers (e.g., "European Middle Pleistocene Homo") is consistent with observed human capabilities for cognitive differentiation, is both necessary and sufficient given the current data, and will allow for the most clear communication across ideologies going forward.

Origin of ethnic groups, linguistic families, and civilizations in China viewed from the Y chromosome

East Asia, geographically extending to the Pamir Plateau in the west, to the Himalayan Mountains in the southwest, to Lake Baikal in the north and to the South China Sea in the south, harbors a variety of people, cultures, and languages. To reconstruct the natural history of East Asians is a mission of multiple disciplines, including genetics, archaeology, linguistics, and ethnology. Geneticists confirm the recent African origin of modern East Asians. Anatomically modern humans arose in Africa and immigrated into East Asia via a southern route approximately 50,000 years ago. Following the end of the Last Glacial Maximum approximately 12,000 years ago, rice and millet were domesticated in the south and north of East Asia, respectively, which allowed human populations to expand and linguistic families and ethnic groups to develop. These Neolithic populations produced a strong relation between the present genetic structures and linguistic families. The expansion of the Hongshan people from northeastern China relocated most of the ethnic populations on a large scale approximately 5300 years ago. Most of the ethnic groups migrated to remote regions, producing genetic structure differences between the edge and center of East Asia. In central China, pronounced population admixture occurred and accelerated over time, which subsequently formed the Han Chinese population and eventually the Chinese civilization. Population migration between the north and the south throughout history has left a smooth gradient in north-south changes in genetic structure. Observation of the process of shaping the genetic structure of East Asians may help in understanding the global natural history of modern humans.

Earliest known human burial in Africa

The origin and evolution of hominin mortuary practices are topics of intense interest and debate^1-3. Human burials dated to the Middle Stone Age (MSA) are exceedingly rare in Africa and unknown in East Africa^1-6. Here we describe the partial skeleton of a roughly 2.5- to 3.0-year-old child dating to 78.3 ± 4.1 thousand years ago, which was recovered in the MSA layers of Panga ya Saidi (PYS), a cave site in the tropical upland coast of Kenya^7,8. Recent excavations have revealed a pit feature containing a child in a flexed position. Geochemical, granulometric and micromorphological analyses of the burial pit content and encasing archaeological layers indicate that the pit was deliberately excavated. Taphonomical evidence, such as the strict articulation or good anatomical association of the skeletal elements and histological evidence of putrefaction, support the in-place decomposition of the fresh body. The presence of little or no displacement of the unstable joints during decomposition points to an interment in a filled space (grave earth), making the PYS finding the oldest known human burial in Africa. The morphological assessment of the partial skeleton is consistent with its assignment to Homo sapiens, although the preservation of some primitive features in the dentition supports increasing evidence for non-gradual assembly of modern traits during the emergence of our species. The PYS burial sheds light on how MSA populations interacted with the dead.

An early Holocene human skull from Zhaoguo cave, Southwestern China

OBJECTIVES

In this study, we describe a newly excavated early Holocene human cranium from Guizhou, Southwestern China, namely the Zhaoguo M1 (ZG 1). We aim to evaluate its morphological resemblance with Late Pleistocene human, and Northern and Southern China Neolithic populations. We also aim to infer its position in the process of East Asian population regionalization.

MATERIALS AND METHODS

The ZG 1 skull is almost complete, only missing parts of the right parietal and the basicranium around the foramen magnum. Comparative samples include Late Pleistocene humans and Neolithic populations from Northern and Southern China. Univariate and multivariate analyses are carried out in the study.

RESULTS

ZG 1 has a dolichocephalic cranium, wide zygomatic breadth, moderate glabella and supraobtial projection, marked canine fossa, and thin cranial vault. The nasal floor, maximum cranial breadth position, and frontal arc proportion are all congruent with modern human. Statistical analysis suggests that ZG 1's measurements are most similar to those of Southern China Neolithic specimens, with some closer to Late Pleistocene humans.

CONCLUSION

ZG 1 shows a clear affinity with Southern China Neolithic populations, providing further support that regionalization of morphological variability patterns between Northern and Southern Neolithic populations could have originated at least 10,000 years ago.

The forensic landscape and the population genetic analyses of Hainan Li based on massively parallel sequencing DNA profiling

Due to the formation of the Qiongzhou Strait by climate change and marine transition, Hainan island was isolated from the mainland southern China during the Last Glacial Maximum. Hainan island, located at the southernmost part of China and separated from the Leizhou Peninsula by the Qiongzhou Strait, laid on one of the modern human northward migration routes from Southeast Asia to East Asia. The Hlai language-speaking Li minority, the second largest population after Han Chinese in Hainan island, is the direct descendants of the initial migrants in Hainan island and has unique ethnic properties and derived characteristics; however, the forensic-associated studies on Hainan Li population are still insufficient. Hence, 136 Hainan Li individuals were genotyped in this study using the MPS-based ForenSeq™ DNA Signature Prep Kit (DNA Primer Set A, DPMA) to characterize the forensic genetic polymorphism landscape, and DNA profiles were obtained from 152 different molecular genetic markers (27 autosomal STRs, 24 Y-STRs, 7 X-STRs, and 94 iiSNPs). A total of 419 distinct length variants and 586 repeat sequence sub-variants, with 31 novel alleles (at 17 loci), were identified across the 58 STR loci from the DNA profiles of Hainan Li population. We evaluated the forensic characteristics and efficiencies of DPMA, demonstrating that the STRs and iiSNPs in DPMA were highly polymorphic in Hainan Li population and could be employed in forensic applications. In addition, we set up three datasets, which included the genetic data of (i) iiSNPs (27 populations, 2640 individuals), (ii) Y-STRs (42 populations, 8281 individuals), and (iii) Y haplogroups (123 populations, 4837 individuals) along with the population ancestries and language families, to perform population genetic analyses separately from different perspectives. In conclusion, the phylogenetic analyses indicated that Hainan Li, with a southern East Asia origin and Tai-Kadai language-speaking language, is an isolated population relatively. But the genetic pool of Hainan Li influenced by the limited gene flows from other Tai-Kadai populations and Hainan populations. Furthermore, the establishment of isolated population models will be beneficial to clarify the exquisite population structures and develop specific genetic markers for subpopulations in forensic genetic fields.

Dental caries in South African fossil hominins

Once considered rare in fossil hominins, caries has recently been reported in several hominin species, requiring a new assessment of this condition during human evolution. Caries prevalence and location on the teeth of South African fossil hominins were observed and compared with published data from other hominin samples. Teeth were viewed macroscopically, with lesion position and severity noted and described. For all South African fossil hominin specimens studied to date, a total of 10 carious teeth (14 lesions), including 4 described for the first time here, have been observed. These carious teeth were found in a minimum of seven individuals, including five Paranthropus robustus, one early Homo, and one Homo naledi. All 14 lesions affected posterior teeth. The results suggest cariogenic biofilms and foods may have been present in the oral environment of a wide variety of hominins. Caries prevalence in studied fossil hominins is similar to those in pre-agricultural human groups, in which 1–5% of teeth are typically affected.

Human molecular evolutionary rate, time dependency and transient polymorphism effects viewed through ancient and modern mitochondrial DNA genomes

Human evolutionary genetics gives a chronological framework to interpret the human history. It is based on the molecular clock hypothesis that suppose a straightforward relationship between the mutation rate and the substitution rate with independence of other factors as demography dynamics. Analyzing ancient and modern human complete mitochondrial genomes we show here that, along the time, the substitution rate can be significantly slower or faster than the average germline mutation rate confirming a time dependence effect mainly attributable to changes in the effective population size of the human populations, with an exponential growth in recent times. We also detect that transient polymorphisms play a slowdown role in the evolutionary rate deduced from haplogroup intraspecific trees. Finally, we propose the use of the most divergent lineages within haplogroups as a practical approach to correct these molecular clock mismatches.

Origins of modern human ancestry

New finds in the palaeoanthropological and genomic records have changed our view of the origins of modern human ancestry. Here we review our current understanding of how the ancestry of modern humans around the globe can be traced into the deep past, and which ancestors it passes through during our journey back in time. We identify three key phases that are surrounded by major questions, and which will be at the frontiers of future research. The most recent phase comprises the worldwide expansion of modern humans between 40 and 60 thousand years ago (ka) and their last known contacts with archaic groups such as Neanderthals and Denisovans. The second phase is associated with a broadly construed African origin of modern human diversity between 60 and 300 ka. The oldest phase comprises the complex separation of modern human ancestors from archaic human groups from 0.3 to 1 million years ago. We argue that no specific point in time can currently be identified at which modern human ancestry was confined to a limited birthplace, and that patterns of the first appearance of anatomical or behavioural traits that are used to define Homo sapiens are consistent with a range of evolutionary histories.

An updated chronology and paleoenvironmental background for the Paleolithic Loufangzi site, North China

The relationship between the environment and human activities during Marine Isotope Stage (MIS) 4 is important for understanding the origins of modern humans (Homo sapiens) in East Asia, an area where various hypotheses of human origins have been vigorously debated over the past three decades. Unfortunately, only a handful of Paleolithic sites date to MIS 4 in East Asia, hampering our understanding of how environmental changes affected human activities during this time period. Here, we used stratigraphic correlation analysis and optically stimulated luminescence to date the Loufangzi site, an important Paleolithic site in North China that has had an unreliable chronology. Pollen analysis, grain size, and magnetic susceptibility were also used to reconstruct environmental conditions at the Loufangzi site area. Our results show that (1) the age of the upper culture layer of the Loufangzi site is bracketed between ∼70 ka and ∼60 ka and dates to MIS 4 and (2) the regional vegetation from MIS 5 to MIS 4 to MIS 3 was mainly dominated by forest steppe, desert steppe/desert, and steppe, respectively, indicating harsh environmental conditions during MIS 4. Combined with the discovery of Mousterian-like scrapers in the upper culture layer of MIS 4, our results challenge the view that the area was unsuitable for human survival during the Last Glacial period and instead suggest that humans used new technologies to increase their resilience to the cooling climate.

Oldest cave art found in Sulawesi

Indonesia harbors some of the oldest known surviving cave art. Previously, the earliest dated rock art from this region was a figurative painting of a Sulawesi warty pig (Sus celebensis). This image from Leang Bulu' Sipong 4 in the limestone karsts of Maros-Pangkep, South Sulawesi, was created at least 43,900 years ago (43.9 ka) based on Uranium-series dating. Here, we report the Uranium-series dating of two figurative cave paintings of Sulawesi warty pigs recently discovered in the same karst area. The oldest, with a minimum age of 45.5 ka, is from Leang Tedongnge. The second image, from Leang Balangajia 1, dates to at least 32 ka. To our knowledge, the animal painting from Leang Tedongnge is the earliest known representational work of art in the world. There is no reason to suppose, however, that this early rock art is a unique example in Island Southeast Asia or the wider region.

Regional impacts of climate change and its relevance to human evolution

The traditional concept of long and gradual, glacial-interglacial climate changes during the Quaternary has been challenged since the 1980s. High temporal resolution analysis of marine, terrestrial and ice geological archives has identified rapid, millennial- to centennial-scale, and large-amplitude climatic cycles throughout the last few million years. These changes were global but have had contrasting regional impacts on the terrestrial and marine ecosystems, with in some cases strong changes in the high latitudes of both hemispheres but muted changes elsewhere. Such a regionalization has produced environmental barriers and corridors that have probably triggered niche contractions/expansions of hominin populations living in Eurasia and Africa. This article reviews the long- and short-timescale ecosystem changes that have punctuated the last few million years, paying particular attention to the environments of the last 650,000 years, which have witnessed key events in the evolution of our lineage in Africa and Eurasia. This review highlights, for the first time, a contemporaneity between the split between Denisovan and Neanderthals, at ~650-400 ka, and the strong Eurasian ice-sheet expansion down to the Black Sea. This ice expansion could form an ice barrier between Europe and Asia that may have triggered the genetic drift between these two populations.

Hominin diversity in East Asia during the Middle Pleistocene: A premolar endostructural perspective

Following the recent studies of East Asian mid-Middle to early Late Pleistocene hominin material, a large spectrum of morphological diversity has been recognized and the coexistence of archaic ('Homo erectus-like') and derived ('modern-like') dental morphological patterns has been highlighted. In fact, for most of these Chinese fossils, generally categorized as 'archaic Homo sapiens' or 'post-H. erectus Homo', the taxonomic attribution is a matter of contention. With the help of μCT techniques and a deformation-based 3D geometric morphometric approach, we focused on the morphological variation in the enamel-dentine junction (EDJ) of 18 upper and lower premolars from Chinese Middle Pleistocene hominins. We then compared our results with a number of fossil and modern human groups, including Early Pleistocene H. erectus from Sangiran; late Early Pleistocene hominins from Tighenif, Algeria; classic Neanderthals; and modern humans. Our results highlight an evolutionary/chronological trend of crown base reduction, elevation of EDJ topography, and EDJ surface simplification in the hominin groups studied here. Moreover, this study brings insights to the taxonomy/phylogeny of 6 late Middle Pleistocene specimens whose evolutionary placement has been debated for decades. Among these specimens, Changyang premolars show features that can be aligned with the Asian H. erectus hypodigm, whereas Panxian Dadong and Tongzi premolars are more similar to Late Pleistocene Homo. Compared with early to mid-Middle Pleistocene hominins in East Asia, late Middle Pleistocene hominins evince an enlarged morphological variation. A persistence of archaic morphotypes and possible admixture among populations during the late Middle Pleistocene are discussed.

The upper limb skeleton and behavioral lateralization of modern humans from Zhaoguo Cave, southwestern China

OBJECTIVES

Aims of the study are to initially describe and comparatively evaluate the morphology of the new Zhaoguo M1 upper limb remains, and contextualize upper limb functional adaptations among those of other worldwide Upper Paleolithic (UP) humans to make inferences about subsistence-related activity patterns in southwestern China at the Pleistocene-Holocene boundary.

MATERIALS AND METHODS

The preserved Zhaoguo M1 skeletal remains include paired humeri, ulnae, and radii, among others. These specimens were scanned using micro-computed tomography to evaluate internal structural properties, while external osteometric dimensions of the Zhaoguo M1 upper limb elements also were acquired. Both sets of measurements were compared to published data on Neandertals, and Middle and Upper Paleolithic modern humans.

RESULTS

The upper limb elements of Zhaoguo M1 display a suite of characteristics that generally resemble those of other contemporary Late UP (LUP) modern humans, while robusticity indices generally fall within the upper range of LUP variation. The Zhaoguo M1 upper limb elements display fewer traits resembling those of late archaic humans. The Zhaoguo M1 individual exhibits diaphyseal asymmetry in several upper limb elements suggesting left hand dominance. When evaluating the full range of magnitudes of humeral bilateral asymmetry in the comparative sample, Zhaoguo M1 falls at the lower end overall, but yet is relatively higher than contemporary LUP modern humans specifically from East Eurasia.

DISCUSSION

The Zhaoguo M1 individual suggests typical LUP modern human upper limb morphology persisted in southwest China until the end of the last glacial period. Upper limb bone asymmetry of Zhaoguo M1 also indicates that behavioral activities attributed to a hunter-gatherer tradition apparently extended through the Pleistocene-Holocene transition in this region.

Triangulating Neanderthal cognition: A tale of not seeing the forest for the trees

The inference of Neanderthal cognition, including their cultural and linguistic capabilities, has persisted as a fiercely debated research topic for decades. This lack of consensus is substantially based on inherent uncertainties in reconstructing prehistory out of indirect evidence as well as other methodological limitations. Further factors include systemic difficulties within interdisciplinary discourse, data artifacts, historic research biases, and the sheer scope of the relevant research. Given the degrees of freedom in interpretation ensuing from these complications, any attempt to find approximate answers to the yet unsettled pertinent discourse may not rest on single studies, but instead a careful and comprehensive interdisciplinary synthesis of findings. Triangulating Neanderthals' cognition by considering the plethora of data, diverse perspectives and aforementioned complexities present within the literature constitutes the currently most reliable pathway to tentative conclusions. While some uncertainties remain, such an approach paints the picture of an extensive shared humanity between anatomically modern humans and Neanderthals. This article is categorized under: Cognitive Biology > Evolutionary Roots of Cognition Linguistics > Evolution of Language.