RESUMO
Despite extensive archaeological research, our knowledge of the human population history of Upper Paleolithic Europe remains limited, primarily due to the scarce availability and poor molecular preservation of fossil remains. As teeth dominate the fossil record and preserve genetic signatures in their morphology, we compiled a large dataset of 450 dentitions dating between ~47 and 7 thousand years ago (ka), outnumbering existing skeletal and paleogenetic datasets. We tested a range of competing demographic scenarios using a coalescent-based machine learning Approximate Bayesian Computation (ABC) framework that we modified for use with phenotypic data. Mostly in agreement with but also challenging some of the hitherto available evidence, we identified a population turnover in western Europe at ~28 ka, isolates in western and eastern refugia between ~28 and 14.7 ka, and bottlenecks during the Last Glacial Maximum. Methodologically, this study marks the pioneering application of ABC to skeletal phenotypes, paving the way for exciting future research avenues.
Assuntos
Fósseis , Fenótipo , Dinâmica Populacional , Dente , Humanos , Europa (Continente) , Dente/anatomia & histologia , Teorema de Bayes , ArqueologiaRESUMO
OBJECTIVES: Grotta-Riparo di Uluzzo C (Apulia, southern Italy) is a pivotal site for investigating the evolution of the Middle Paleolithic and the earliest phases of the Upper Paleolithic in southern Italy, as the extensive stratigraphic record of this site includes a thick Mousterian sequence followed by the Uluzzian. Here, we investigate the taxonomic affinity of seven unpublished deciduous human teeth retrieved from the site of Uluzzo C in 1960. MATERIALS AND METHODS: The teeth are represented by seven plaster dental casts, which are housed at the Museo Civico di Paleontologia e Paletnologia in Maglie (Lecce, Apulia). The location of the original specimens remains unknown, rendering these casts the only human remains evidence yielded by Uluzzo C to date. Based on occlusal-view photographs and digital models of the casts, we examined the external morphology and morphometry of the teeth, comparing them to Homo sapiens and H. neanderthalensis samples. Through geometric morphometric methods and statistical analyses, we analyzed the crown outline of the deciduous molars. RESULTS: The teeth show morphological and morphometric features that are variably found in H. neanderthalensis, H. sapiens, or both. Specifically, crown outline analysis shows that all molars fall within H. neanderthalensis variability, except for Uluzzo 853 (lower right deciduous first molar), which falls within H. sapiens variability. DISCUSSION: This study provides the first taxonomic assessment of the hominin teeth from Uluzzo C. The results contribute additional insights into the Paleolithic peopling of southern Italy during a crucial period marked by the persistence of post-Tyrrhenian Neanderthal techno-complexes and the arrival of H. sapiens.
Assuntos
Fósseis , Hominidae , Itália , Animais , Hominidae/anatomia & histologia , Humanos , Dente Decíduo/anatomia & histologia , Homem de Neandertal/anatomia & histologia , Dente/anatomia & histologia , Dente Molar/anatomia & histologia , Paleodontologia , Modelos DentáriosRESUMO
More than 150 hominin teeth, dated to â¼330-241 thousand years ago, were recovered during the 2013-2015 excavations of the Dinaledi Chamber of the Rising Star cave system, South Africa. These fossils comprise the first large single-site sample of hominin teeth from the Middle Pleistocene of Africa. Though scattered remains attributable to Homo sapiens, or their possible lineal ancestors, are known from older and younger sites across the continent, the distinctive morphological feature set of the Dinaledi teeth supports the recognition of a novel hominin species, Homo naledi. This material provides evidence of African Homo lineage diversity that lasts until at least the Middle Pleistocene. Here, a catalog, anatomical descriptions, and details of preservation and taphonomic alteration are provided for the Dinaledi teeth. Where possible, provisional associations among teeth are also proposed. To facilitate future research, we also provide access to a catalog of surface files of the Rising Star jaws and teeth.
Assuntos
Hominidae , Dente , Humanos , Animais , África do Sul , Hominidae/anatomia & histologia , Fósseis , Cavernas , Evolução BiológicaRESUMO
The oldest Oldowan tool sites, from around 2.6 million years ago, have previously been confined to Ethiopia's Afar Triangle. We describe sites at Nyayanga, Kenya, dated to 3.032 to 2.581 million years ago and expand this distribution by over 1300 kilometers. Furthermore, we found two hippopotamid butchery sites associated with mosaic vegetation and a C4 grazer-dominated fauna. Tool flaking proficiency was comparable with that of younger Oldowan assemblages, but pounding activities were more common. Tool use-wear and bone damage indicate plant and animal tissue processing. Paranthropus sp. teeth, the first from southwestern Kenya, possessed carbon isotopic values indicative of a diet rich in C4 foods. We argue that the earliest Oldowan was more widespread than previously known, used to process diverse foods including megafauna, and associated with Paranthropus from its onset.
Assuntos
Evolução Biológica , Dieta , Comportamento Alimentar , Hominidae , Animais , Osso e Ossos , Fósseis , Quênia , Plantas , PaleontologiaRESUMO
There are scant human remains associated with Early Upper Paleolithic (EUP) industries. The rock shelter at Ksâr 'Akil, Lebanon, is one of the few circum-Mediterranean archaeological sites with EUP artifacts and associated fossils attributed to Homo sapiens. The skull and post-crania of the juvenile 'Egbert' (Ksâr 'Akil 1) from the EUP levels (conservatively dated from â¼43 to 39 ka) have been lost; the partial edentulous maxilla of 'Ethelruda' (Ksâr 'Akil 2) from the Initial Upper Paleolithic levels has only recently been rediscovered, leaving an isolated deciduous molar (Ksâr 'Akil 3) from Levantine Aurignacian strata. A fourth individual was found adjacent to Ksâr 'Akil 1 in 1938, but never described, and is apparently also lost. New archival research at the Peabody Museum of Archaeology and Ethnography uncovered photographs and radiographs of Ksâr 'Akil 1 and photographs of the fourth individual (which we designate Ksâr 'Akil 4). These new photographs and radiographs allow a comparative dental analysis of both individuals. Radiographs confirm an age of 7-8 years for Ksâr 'Akil 1 and photographs of Ksâr 'Akil 4 suggest a similar, if not slightly younger, age. Compared to other fossil H. sapiens, the teeth of Ksâr 'Akil 1 and Ksâr 'Akil 4 are remarkably modern. The upper deciduous third premolars lack a hypocone and metacone; the upper deciduous fourth premolars of Ksâr 'Akil 1 have reduced hypocones and both individuals have upper fourth premolars and first molars with square (as opposed to skewed) occlusal outlines, resulting from a hypocone that is smaller than, or equal in size to, the metacone. The lower first permanent molars of Ksâr 'Akil 1, and possibly Ksâr 'Akil 4, are four-cusped, which is a rare trait among Paleolithic and recent H. sapiens.
Assuntos
Hominidae , Animais , Humanos , Criança , Dentição , Líbano , Arqueologia , Dente Molar , FósseisRESUMO
Overcoming the non-specificity of histological accentuated growth lines in hard tissues is an ongoing challenge. Identifying season at death and reproductive events has profound implications for evolutionary, ecological and conservation studies. Dental cementum is a mineralized tissue with yearly periodicity that continues deposition from tooth formation until death, maintaining a record spanning almost the entire life of an individual. Recent work has successfully employed elemental analysis of calcified incremental tissues to detect changes in extrinsic conditions such as diet and climate and to identify two important life-history milestones: weaning and sexual maturity. Here, we employ field-emission scanning electron microscopy and energy-dispersive X-ray analysis to measure the relative concentrations of calcium, phosphorous, oxygen, magnesium and sodium in the cementum of 34 teeth from seven male and female rhesus macaques with known medical and life-history information. We find that changes in relative magnesium concentrations correspond with reproductive events in females and breastfeeding in infants. Additionally, we observe seasonal calcium patterns in 77.3% of the samples.
Assuntos
Cálcio , Dente , Animais , Masculino , Feminino , Magnésio , Macaca mulatta , Microscopia Eletrônica de VarreduraRESUMO
Extracting life history information from mineralized hard tissues of extant and extinct species is an ongoing challenge in evolutionary and conservation studies. Primary lamellar bone is a mineralized tissue with multidien periodicity that begins deposition prenatally and continues until adulthood albeit with concurrent resorption, thus maintaining a record spanning several years of an individual's life. Here, we use field-emission scanning electron microscopy and energy-dispersive X-ray analysis to measure the relative concentrations of calcium, phosphorous, oxygen, magnesium and sodium in the femora of seven rhesus macaque with known medical and life-history information. We find that the concentration of these elements distinguishes parous from nulliparous females; that in females calcium and phosphorus are lower in bone formed during reproductive events; and that significant differences in relative magnesium concentration correlate with breastfeeding in infants.
Assuntos
Cálcio , Magnésio , Animais , Feminino , Magnésio/análise , Macaca mulatta , Cálcio/análise , Fósforo/análise , Sódio/análiseRESUMO
Many open questions in evolutionary studies relate to species' physiological adaptations, including the evolution of their life history and reproductive strategies. There are few empirical methods capable of detecting and timing physiologically impactful events such as weaning, parturition and illnesses from hard tissue remains of either extant or extinct species. Cementum is an incremental tissue with post eruption annual periodicity, which covers the tooth root and functions as a recording structure of an animal's physiology. Here we test the hypothesis that it is possible to detect and time physiologically impactful events through the analysis of dental cementum microstructure. Our sample comprises 41 permanent and deciduous teeth from male and female rhesus macaques (Macaca mulatta) with known medical, lifestyle and life history information. We develop a semi-automated method of cementum histological analysis for the purpose of event detection and timing, aimed at significantly reducing the amount of intra- and interobserver errors typically associated with histological analyses. The results of our work show that we were able to detect known events including weaning, parturition, illness and physical trauma with high accuracy (false negative rate = 3.2%; n = 1), and to time them within an average absolute difference of 0.43 years (R2 = .98; p < .05). Nonetheless, we could not distinguish between the several types of stressful events underlying the changes in cementum microstructure. While this study is the first to identify a variety of life history events in macaque dental cementum, laying foundations for future work in conservation and evolutionary studies of both primates and toothed mammals at large, there are some limitations. Other types of analyses (possibly chemical ones) are necessary to tease apart the causes of the stressors.
Assuntos
Cemento Dentário , Dente , Animais , Feminino , Macaca mulatta , Masculino , Parto , Gravidez , DesmameRESUMO
OBJECTIVES: The purpose of this study is to help elucidate the taxonomic relationship between Homo naledi and other hominins. MATERIALS AND METHODS: Homo naledi deciduous maxillary and mandibular molars from the Dinaledi Chamber, South Africa were compared to those of Australopithecus africanus, Australopithecus afarensis, Paranthropus robustus, Paranthropus boisei, early Homo sp., Homo erectus, early Homo sapiens, Upper Paleolithic H. sapiens, recent southern African H. sapiens, and Neanderthals by means of morphometric analyses of crown outlines and relative cusp areas. The crown shapes were analyzed using elliptical Fourier analyses followed by principal component analyses (PCA). The absolute and relative cusp areas were obtained in ImageJ and compared using PCA and cluster analyses. RESULTS: PCA suggests that the crown shapes and relative cusp areas of mandibular molars are more diagnostic than the maxillary molars. The H. naledi deciduous mandibular first and second molar (dm1 and dm2 ) do not have a strong affinity to any taxon in the comparative sample in all analyses. While the H. naledi dm2 plots as an outlier in the relative cusp analysis, the H. naledi specimen fall closest to Australopithecus due to their relatively large metaconid, a primitive trait for the genus Homo. Although useful for differentiating Neanderthals from recent southern African H. sapiens and UP H. sapiens, the PCA of the relative cusp areas suggests that the deciduous maxillary second molars (dm2 ) do not differentiate other groups. The three H. naledi dm2 cuspal areas are variable and fall within the ranges of other Homo, as well as Australopithecus, and Paranthropus suggesting weak diagnostic utility. DISCUSSION: This research provides another perspective on the morphology of, and variation within, H. naledi. The H. naledi deciduous molars do not consistently align with any genus or species in the comparative sample in either the crown shape or relative cusp analyses. This line of inquiry is consistent with other cranial and postcranial studies suggesting that H. naledi is unique.
Assuntos
Hominidae/anatomia & histologia , Hominidae/classificação , Dente Molar/anatomia & histologia , Animais , Antropologia Física , Fósseis , Humanos , Homem de Neandertal/anatomia & histologia , Homem de Neandertal/classificação , Odontometria , Análise de Componente Principal , África do SulRESUMO
OBJECTIVES: Enamel thickness features prominently in hominoid evolutionary studies. To date, however, studies of enamel thickness in humans, great apes, and their fossil relatives have focused on the permanent molar row. Comparatively little research effort has been devoted to tissue proportions within deciduous teeth. Here we attempt to fill this gap by documenting enamel thickness variation in the deciduous dentition of extant large-bodied hominoids. MATERIALS AND METHODS: We used microcomputed tomography to image dental tissues in 80 maxillary and 78 mandibular deciduous premolars of Homo sapiens, Pan troglodytes, Gorilla, and Pongo. Two-dimensional virtual sections were created from the image volumes to quantify average (AET) and relative (RET) enamel thickness, as well as its distribution across the crown. RESULTS: Our results reveal no significant differences in enamel thickness among the great apes. Unlike the pattern present in permanent molars, Pongo does not stand out as having relatively thicker-enameled deciduous premolars than P. troglodytes and Gorilla. Humans, on the other hand, possess significantly thicker deciduous premolar enamel in comparison to great apes. Following expectations from masticatory biomechanics, we also find that the "functional" side (protocone, protoconid) of deciduous premolars generally possesses thicker enamel than the "nonfunctional" side. DISCUSSION: Our study lends empirical support to anecdotal observations that patterns of AET and RET observed for permanent molars of large-bodied apes do not apply to deciduous premolars. By documenting enamel thickness variation in hominoid deciduous teeth, this study provides the comparative context to interpret rates and patterns of wear of deciduous teeth and their utility in life history reconstructions.
Assuntos
Esmalte Dentário/anatomia & histologia , Fósseis , Hominidae/anatomia & histologia , Dente Decíduo/anatomia & histologia , Animais , Dente Pré-Molar/anatomia & histologia , Dente Pré-Molar/diagnóstico por imagem , Esmalte Dentário/diagnóstico por imagem , Feminino , Humanos , Masculino , Dente Decíduo/diagnóstico por imagem , Microtomografia por Raio-XRESUMO
The life history pattern of recent humans is uniquely derived in many of its aspects including an extended post-reproductive lifespan combined with short interbirth intervals. A number of theories have been proposed to explain the evolution of this unusual pattern. However most have been difficult to test due to the fragmentary nature of the hominin fossil record and the lack of methods capable of inferring such later life history events. In search of a method we tested the hypothesis that the physiologically impactful events of parturition and menopause are recorded in dental cementum microstructure. We performed histomorphological analyses of 47 teeth from 15 individuals with known life history events and were able to detect reproductive events and menopause in all females. Furthermore, we found that other stressful events such as systemic illnesses and incarceration are also detectable. Finally, through the development of a novel analytical method we were able to time all such events with high accuracy (R-squared = 0.92).
Assuntos
Cemento Dentário/anatomia & histologia , Cemento Dentário/química , Cemento Dentário/metabolismo , Animais , Evolução Biológica , Feminino , Fósseis/anatomia & histologia , Hominidae/anatomia & histologia , Humanos , Menopausa/metabolismo , Parto/metabolismo , Gravidez , Reprodução/fisiologia , Estresse Fisiológico/fisiologia , Dente/anatomia & histologiaAssuntos
Fósseis , Dente Molar/anatomia & histologia , Povo Asiático , Humanos , Mandíbula , FenótipoRESUMO
OBJECTIVES: The taxonomic status of isolated hominoid teeth from the Asian Pleistocene has long been controversial due to difficulties distinguishing between pongine and hominin molars given their high degree of morphometrical variation and overlap. Here, we combine nonmetric and geometric morphometric data to document a dental pattern that appears to be taxonomically diagnostic among Pongo. We focus on the protoconule, a cuspule of well-documented evolutionary history, as well as on shape differences of the mesial fovea of the upper molars. MATERIALS AND METHODS: We examined 469 upper molars of eight hominid genera (Australopithecus, Paranthropus, Homo, Meganthropus, Sivapithecus, Pan, Gorilla, and Pongo), including representatives of Homo erectus and extinct and recent Pongo. Analyses were conducted at the enamel-dentine junction to overcome the limitations introduced by dental wear. RESULTS: We found that a moderate or large protoconule is present in ~80% of Pleistocene and extant Pongo. Conversely, a moderate to pronounced protoconule in hominins, Meganthropus, and African great apes occurs in low frequencies (~0-20%). Canonical variate analyses for the mesial fovea show that Pleistocene and extant Pongo cluster together and are clearly differentiated from all other groups, except for Sivapithecus. DISCUSSION: This study suggests that the protoconule and the shape of the mesial fovea in upper molars are useful features for the taxonomic identification of isolated hominid teeth. By identifying these new features, our results can contribute to the better understanding of hominoid evolutionary history and biogeography during the Asian Pleistocene. However, we emphasize that the reported features should be used in combination with other diagnostic variables for the most accurate taxonomic assessments.
Assuntos
Hominidae/anatomia & histologia , Dente Molar/anatomia & histologia , Animais , Hominidae/classificação , Mandíbula , Pongo/anatomia & histologiaRESUMO
In 2013, 2014 new hominin remains were uncovered in the Dinaledi chamber of the Rising Star cave system in South Africa. In 2015 Berger and colleagues identified these remains as belonging to a new species Homo naledi (Berger et al., 2015). Subsequent comparative studies of the skull, postcrania and permanent dentition have supported this taxonomic affiliation (Harcourt-Smith et al., 2015; Kivell et al., 2015; Irish et al., 2018). The deciduous teeth can offer unique insights into hominin evolution. Due to their early onset and rapid development their morphology is thought to be under stronger genetic control and less influenced by environment than are the permanent teeth. In this study we compared the H. naledi deciduous teeth from the 2013-2014 excavations to samples representing much of the hominin clade including Australopithecus afarensis, Australopithecus africanus, Paranthropus boisei, Paranthropus robustus, early Homo, Homo antecessor, Homo erectus s.l., Homo floresiensis, Middle Pleistocene Homo, Homo neanderthalensis, early Homo sapiens and recent H. sapiens from Sub-Saharan Africa. By making such a broad morphological comparison, we aimed to contextualize the Dinaledi hominins and to further assess the validity of their taxonomic assignment. Our analysis of the deciduous teeth revealed a unique combination of features that mirror (but also expand) that found in the permanent teeth. This mosaic includes an asymmetrical lower canine with a distal tubercle, an upper first molar with a large hypocone and epicrista associated with a mesial cuspule, a molarized lower first molar resembling Paranthropus, and upper and lower second molars that resemble later Homo in their lack of accessory cusps. The unique combination of deciduous dental characters supports previous studies assigning H. naledi to a new species, although its phylogenetic position vis-à-vis other Homo species remains ambiguous.
Assuntos
Fósseis/anatomia & histologia , Hominidae/anatomia & histologia , Dente Decíduo/anatomia & histologia , Animais , Hominidae/crescimento & desenvolvimento , Humanos , Homem de Neandertal/anatomia & histologia , Homem de Neandertal/crescimento & desenvolvimento , Dente Decíduo/crescimento & desenvolvimentoRESUMO
The recently described Denisovan hemimandible from Xiahe, China [F. Chen et al., (2019) Nature 569, 409-412], possesses an unusual dental feature: a 3-rooted lower second molar. A survey of the clinical and bioarchaeological literature demonstrates that the 3-rooted lower molar is rare (less than 3.5% occurrence) in non-Asian Homo sapiens In contrast, its presence in Asian-derived populations can exceed 40% in China and the New World. It has long been thought that the prevalence of 3-rooted lower molars in Asia is a relatively late acquisition occurring well after the origin and dispersal of H. sapiens However, the presence of a 3-rooted lower second molar in this 160,000-y-old fossil hominin suggests greater antiquity for the trait. Importantly, it also provides morphological evidence of a strong link between archaic and recent Asian H. sapiens populations. This link provides compelling evidence that modern Asian lineages acquired the 3-rooted lower molar via introgression from Denisovans.
Assuntos
Evolução Molecular , Fósseis/anatomia & histologia , Hominidae/anatomia & histologia , Dente Molar/anatomia & histologia , Animais , Povo Asiático/genética , Hominidae/genética , Humanos , Mandíbula/anatomia & histologiaRESUMO
Denisovans are members of a hominin group who are currently only known directly from fragmentary fossils, the genomes of which have been studied from a single site, Denisova Cave1-3 in Siberia. They are also known indirectly from their genetic legacy through gene flow into several low-altitude East Asian populations4,5 and high-altitude modern Tibetans6. The lack of morphologically informative Denisovan fossils hinders our ability to connect geographically and temporally dispersed fossil hominins from Asia and to understand in a coherent manner their relation to recent Asian populations. This includes understanding the genetic adaptation of humans to the high-altitude Tibetan Plateau7,8, which was inherited from the Denisovans. Here we report a Denisovan mandible, identified by ancient protein analysis9,10, found on the Tibetan Plateau in Baishiya Karst Cave, Xiahe, Gansu, China. We determine the mandible to be at least 160 thousand years old through U-series dating of an adhering carbonate matrix. The Xiahe specimen provides direct evidence of the Denisovans outside the Altai Mountains and its analysis unique insights into Denisovan mandibular and dental morphology. Our results indicate that archaic hominins occupied the Tibetan Plateau in the Middle Pleistocene epoch and successfully adapted to high-altitude hypoxic environments long before the regional arrival of modern Homo sapiens.
Assuntos
Fósseis , Hominidae/anatomia & histologia , Mandíbula/anatomia & histologia , Altitude , Animais , Cavernas , Hominidae/classificação , Migração Humana , Humanos , Filogenia , Tibet , Dente/anatomia & histologiaRESUMO
In the originally published version of this Letter, the x axis in Fig. 3a should have been: 'PC1: 26%' rather than 'PC1: 46%', and the y axis should have been: 'PC2: 16%' rather than 'PC2: 29%'. We also noticed an error in the numbering of the fossils from Qafzeh: Qafzeh 27 should be removed, and Qafzeh 26 is actually Qafzeh 25, following Tillier (2014)1 and Schuh et al. (2017)2 and personal communication with B. Vandermeersch and M. D. Garralda. The correct enumeration of Qafzeh samples in the 'Mandibular metric data' section of the Methods is therefore: 'Qafzeh (9, 25)' rather than 'Qafzeh (9, 26, 27)'. Owing to the removal of Qafzeh 27, the convex hull of early modern humans changes slightly in Extended Data Fig. 1c. The sample sizes in Extended Data Fig. 1c should have read: Middle Pleistocene archaic Homo n = 19 (instead of 11), Neanderthals n = 40 (instead of 41), early modern humans n = 12 (instead of 7), and recent modern humans n = 46 (instead of 48). In Extended Data Table 2, the mean and standard deviation of corpus height and breadth at mental foramen for early modern humans should have been: xÌ = 33.15, σ = 3.26 for height (rather than xÌ = 34.23, σ = 4.57); and xÌ = 16.25, σ = 1.28 for breadth (rather than xÌ = 16.04, σ = 1.75). Accordingly, n = 12 (rather than n = 13) for both breadth and height. These errors have been corrected in the Letter online (the original Extended Data Fig. 1 is shown in Supplementary Information to this Amendment). These changes do not alter any inferences drawn from the data.
RESUMO
A new species of Homo, Homo naledi, was described in 2015 based on the hominin skeletal remains from the Dinaledi Chamber of the Rising Star cave system, South Africa. Subsequent craniodental comparative analyses, both phenetic and cladistic, served to support its taxonomic distinctiveness. Here we provide a new quantitative analysis, where up to 78 nonmetric crown and root traits of the permanent dentition were compared among samples of H. naledi (including remains from the recently discovered Lesedi Chamber) and eight other species from Africa: Australopithecus afarensis, Australopithecus africanus, Paranthropus boisei, Paranthropus robustus, Homo habilis, Homo erectus, Middle Pleistocene Homo sp., and Pleistocene and Holocene Homo sapiens. By using the mean measure of divergence distance statistic, phenetic affinities were calculated among samples to evaluate interspecific relatedness. The objective was to compare the results with those previously obtained, to assess further the taxonomic validity of the Rising Star hominin species. In accordance with earlier findings, H. naledi appears most similar dentally to the other African Homo samples. However, the former species is characterized by its retention and full expression of features relating to the main cusps, as well as the root numbers, with a near absence of accessory traits-including many that, based on various cladistic studies, are plesiomorphic in both extinct and extant African hominins. As such, the present findings provide additional support for the taxonomic validity of H. naledi as a distinct species of Homo.