Homo Naledi Research Articles

Mosaic Nature of H. naledi

Homo naledi (“Star Man”) holds a fascinating morphology of primitive and derived traits, and offers more questions than answers as to their true functions. In this paper, I will attempt to discern some answers by first describing H. naledi’s outstanding morphological traits with merit to the researchers who found the specimens, as well as discuss its overarching significance in the field of palaeoanthropology. I will then investigate the theories regarding H. naledi’s behavior dissected through comparisons with other hominins, such as contemporary archaic Homo members, argue for a semi-rock climbing morphology rather than semi-arboreal, provide evidence for a possible one million year old stasis through the lenses of neurobiology and ecology, and finally question how these attributed to this species’ extinction. Although a large portion of this paper is theoretical, it nonetheless stems from evidence directly corresponding to the remains of H. naledi.

What we know and do not know after the first decade of Homo naledi.

It has been just over 10 years since the first fossils attributed to Homo naledi were recovered from the Rising Star Cave system in South Africa's Cradle of Humankind. The hominin fossil evidence for H. naledi displays a distinctive combination of primitive and derived morphology, yet for a time-averaged fossil sample it is remarkable for its relatively low level of variation. Thus-unusually for palaeoanthropology-there has been little pushback against the decision to recognize a single novel taxon for all of the material recovered from the Rising Star Cave system. However, almost everything else claimed about H. naledi-its age, burial context and behaviour-has been controversial. Here we examine the strength of the evidence for these claims.

The endocast morphology of LES1, Homo naledi.

Homo naledi is near the extreme of small brain size within Homo but is easily recognized as Homo in other aspects of endocast morphology. This study adds new evidence of the endocast morphology of H. naledi by describing the Lesedi Hominin 1 (LES1) endocranium from the Lesedi Chamber and compares it to the previously known H. naledi individual Dinaledi Hominin 3 (DH3) as well as other hominin taxa. We examined interlandmark distances with both univariate and multivariate methods in multiple hominin taxa and both species of Pan. For each distance, we compared groups using adjusted Z-scores (Azs). Our multivariate analyses included both principal component analyses (PCA) and linear discriminant analyses (LDA). DH3 and LES1 each have absolute third frontal convolution measures that enter the upper half of the variation for Homo sapiens, Homo erectus, and Homo neanderthalensis. Examined relative to the cube root of endocranial volume, H. naledi ranks among the highest values in these samples of Homo. Both absolute and relative values for H. naledi specimens are far above Pan, Australopithecus, and Paranthropus, suggesting an expanded Broca's area. Both qualitative and quantitative analyses show consistency between LES1 and other H. naledi endocasts and confirm the shared morphology of H. naledi with H. sapiens, H. neanderthalensis, and some specimens of H. erectus.

An examination of Homo naledi early juveniles recovered from the Rising Star cave system, South Africa

Background Six Homo naledi early juveniles were recovered from U.W. 101 (Dinaledi Chamber), U.W. 102 (Lesedi Chamber), and U.W. 110 in the Rising Star cave system. Aim This paper develops the information for the H. naledi early juvenile life stage, as defined by a combination of deciduous and permanent dentition, and the eruption of the first permanent molar. Subjects and methods The growing number of young individuals recovered from the Rising Star cave system allows us to gain a better understanding of their variation, or lack thereof, and provides a basis to estimate broad ranges for age at death of the individuals. The individuals are identified and described through craniodental remains and spatial associations. Results and conclusion Our results show that the teeth are remarkably consistent across the localities in their metric and non-metric traits, and our analyses refine previous estimations on dental eruptions with the first permanent molar erupting first in the sequence among permanent teeth.

Linear enamel hypoplasia in Homo naledi reappraised in light of new Retzius periodicities.

Among low-latitude apes, developmental defects of enamel often recur twice yearly, linkable to environmental cycles. Surprisingly, teeth of Homo naledi from Rising Star in South Africa (241-335 kya), a higher latitude site with today a single rainy season, also exhibit bimodally distributed hypoplastic enamel defects, but with uncertain timing and etiology. Newly determined Retzius periodicities for enamel formation in this taxon enable a reconstruction of the temporal patterning of childhood stress. Using high resolution casts of 31 isolated anterior teeth from H. naledi, 82 enamel defects (linear enamel hypoplasia [LEH]) were identified. Seventeen teeth are assigned to three individuals. Perikymata in the occlusal wall of enamel furrows and between the onsets of successive LEH were visualized with scanning electron microscopy and counted. Defects were measured with an optical scanner. Conversion of perikymata counts to estimates of LEH duration and inter-LEH interval draws upon Retzius periodicities of 9 and 11 days. Anterior teeth record more than a year of developmental distress, expressed as two asymmetric intervals centered on 4.5 and 7.5 months bounded by three LEH. Durations, also, show bimodal distributions, lasting 3 or 12 weeks. Short duration LEH are more severe than long duration. Relative incisor/canine rates of formation are indistinguishable from modern humans. We invoke a disease and dearth model, with short episodes of distress reflecting onset of disease in young infants, lasting about 3 weeks, followed by a season of undernutrition, possibly intensified by secondary plant compounds, spanning about 12 weeks, inferably coincident with austral winter.

No scientific evidence that Homo naledi buried their dead and produced rock art

No scientific evidence that Homo naledi buried their dead and produced rock art

Human Fossils from the First Quarter of the 21st Century

Significant discoveries have been made from the first quarter of this Century in the field of evolutionary biology to redefine the human evolution. Discoveries present the morphological variability in fossil forms and indicate the valuable role of that particular continent in tracing the human origin. This article presents a general review of the human fossils found so far of this century that force us to rethink about the current concept of human origin. Most of the fossils have been found in East Africa, South Africa, Central Africa, Russia, Israel and Indonesia. Some of these are related to Australopithecus afarensis, some to Aus. africanus while some to Neanderthal. A complete human skeleton remains has been found from Ethiopia (Middle Awash region) and named as Ardipithecus ramidus is believed to be the common ancestor of humans and chimpanzees. Naser Ramla from Israelis considered as an ancestor of Neanderthals because it used stone tool production technology to make tools. Some fossils share features of both Australopithecus and early Homo, such as Orrorin tugenesis and Homo naledi. Australopithecus deyremeda is considered as an extinct species of Australopithecine. Some of these are contemporary of modern humans, such as Homo florensis, whose complete skeleton has been found from the Flores island of Indonesia and it has also been considered as an Asian descendant of Homoerectus. Denisovans found in Russia's Denisova cave is considered as a new species, it belongs to the Lower Middle Palaeolithic period, so it is also considered to be related to Neanderthal, although its fossil remains include only digit bone, 4 tooth, parts of jaw and long bones and parietal part of the cranium.

Trabecular bone structure of the proximal capitate in extant hominids and fossil hominins with implications for midcarpal joint loading and the dart-thrower's motion.

This research examines whether the distribution of trabecular bone in the proximal capitates of extant hominids, as well as several fossil hominin taxa, is associated with the oblique path of the midcarpal joint known as the dart-thrower's motion (DTM). We analyzed proximal capitates from extant (Pongo n = 12; Gorilla n = 11; Pan n = 10; fossil and recent Homo sapiens n = 29) and extinct (Australopithecus sediba n = 2; Homo naledi n = 1; Homo floresiensis n = 2; Neandertals n = 3) hominids using a new canonical holistic morphometric analysis, which quantifies and visualizes the distribution of trabecular bone using relative bone volume as a fraction of total volume (rBV/TV). Homo sapiens and Neandertals had a continuous band of high rBV/TV that extended across the scaphoid, lunate, and hamate subarticular regions, but other fossil hominins and extant great apes did not. A. sediba expressed a distinct combination of human-like and Pan-like rBV/TV distribution. Both H. floresiensis and H. naledi had high rBV/TV on the ulnar-side of the capitate but low rBV/TV on the radial-side. The proximal capitates of H. sapiens and Neandertals share a distinctive distribution of trabecular bone that suggests that these two species of Homo regularly load(ed) their midcarpal joints along the full extent of the oblique path of the DTM. The observed pattern in A. sediba suggests that human-like stress at the capito-scaphoid articular surface was combined with Pan-like wrist postures, whereas the patterns in H. floresiensis and H. naledi suggest their midcarpal joints were loaded differently from that of H. sapiens and Neandertals.

Descriptive catalog of Homo naledi dental remains from the 2013 to 2015 excavations of the Dinaledi Chamber, site U.W. 101, within the Rising Star cave system, South Africa

More than 150 hominin teeth, dated to ∼330–241 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.

Revisiting the age of the Florisbad hominin material

In 1996, Grün and coworkers provided an ESR age determination for a hominin molar from Florisbad, South Africa, at 259 ± 35 ka. The most anatomically informative hominin specimen from Florisbad is a fragmentary craniofacial specimen, attributed by many to early Homo sapiens, which has been assumed to derive from the same individual as this tooth. Since 1996, evidence about the evolutionary context for the later Middle Pleistocene and its associated hominins in Africa had markedly changed. If the Florisbad date is accurate and if the molar is associated with the craniofacial specimen, this evidence may suggest that Homo naledi coexisted in time and geography with H. sapiens in southern Africa. Thus, the accuracy for all dates needs critical investigation. This study examines the published record of excavation and subsequent analyses for the Florisbad material. We find that the contemporary records raise doubt about the contemporaneity of the tooth and calvaria. The site's complex stratigraphy and the details about the tooth's discovery also pose challenges for the previous ESR age estimate. Because the fragmentary cranial specimen has value for morphological comparisons, developing additional means of understanding its geological age is necessary. The current data do not demonstrate the presence of H. sapiens in southern Africa at ~260 ka.

Aplicación de tecnologías 3D para reproducciones museísticas: el cráneo de Homo naledi del MNCN

The main objective of the work presented here has been to develop an appropriate approach for making a reproduction of a hominid skull, specifically of Homo naledi, the original of which was discovered at the Rising Star cave site (South Africa), and is on display at the University of the Witwatersrand, Johannesburg (South Africa) where it is kept for research. The fragility of the skull made it impossible to carry out a direct molding process on it and, for this reason, digitization and 3D printing techniques have been applied and a second phase that involved carrying out a traditional molding on the impression. The copy of this piece is currently part of the permanent exhibition of the National Museum of Natural Sciences in Madrid. He highlights the importance that 3D techniques present for the field of research, dissemination and conservation of cultural heritage.

Preliminary comparison of close-range photogrammetric and microCT scanning: Surface Deviation Analysis of 3D digital models of hominin molar crowns

This study is a preliminary assessment of the viability of close-range photogrammetry in comparison to microCT scanning for the construction of 3D models of isolated molar crowns. Photogrammetric scanning is more cost-effective and less time-consuming than CT scanning, and in paleoanthropological contexts eliminates the possibility of exposing fossils to doses of radiation that affect ESR dating. Samples of fossil (Homo naledi), archaeological, and contemporary human molars were scanned via microCT and close-range photogrammetric scanning. The photogrammetric scans included 96 digital images per tooth and the resulting models were compared to their corresponding CT models using point-to-point Surface Deviation Analysis. The surface difference between the CT mesh models before and after processing functions such as smoothing and retriangulation was also assessed. Signed-rank tests comparing the surface difference between the two sets of mesh pairs show no significant difference in the level of deviation within the archaeological and contemporary molar samples. The Dinaledi sample demonstrates complementary results, as the majority of the photogrammetric meshes fall within a devised acceptable range of difference when compared to the processed CT meshes. A total of 81% of specimens in the study with suitable characteristics—a stained and unreflective crown surface—provided photogrammetric meshes that fell into this devised range. Crown characteristics that produced unsuitable models had unstained and reflective surfaces. Areas of higher deviation tend to occur in crenulations and fissures. The exploratory results suggest that sufficient reflectance and color contrast data must be present on the tooth enamel to create viable photogrammetric surface models, however further study is needed to fully understand the capabilities and limitations of close-range photogrammetry in comparison to microCT scanning.

Did Homo naledi dispose of their dead in the Rising Star Cave system?

Did Homo naledi dispose of their dead in the Rising Star Cave system?

Homo naledi lumbar vertebrae and a new 3D method to quantify vertebral wedging

AbstractObjectivesIn humans and known fossil hominins, lumbar lordosis is produced by vertebral body wedging and other bony and soft tissue features such as the shape of the intervertebral discs. Current techniques for quantifying the wedging of vertebral bodies are limited in utility, especially when analyzing incomplete fossil material. Here, we introduce a 3D method to quantify vertebral body wedging angles that yields the angles between two “best fit” planes in the software GeoMagic Wrap (3D Systems).Materials and MethodsTo test that this new method is repeatable with existing methods, we measure the wedging of 320 lumbar vertebrae representing 64 modern human individuals. For each vertebra, wedging angles were calculated from linear measurements taken with calipers and compared with estimates generated from the 3D best fit plane method. We also apply the 3D plane method to fossil hominin lumbar vertebrae, including newly described lumbar vertebrae of Homo naledi, the majority of which do not preserve the four landmarks necessary to calculate wedging angles using the traditional approach.ResultsThe results of the two methods are highly and significantly correlated (r2 = 0.98, p < 0.0001). The 3D plane method was successfully applied to nearly all of the fossil hominin specimens included in the study.DiscussionThe new 3D plane method introduced here is repeatable with the traditional linear measurement method and allows for the estimation of wedging angles in incomplete material. When applied to Homo naledi lumbar vertebrae, similarities to other fossil hominins and modern humans are found.

The immature Homo naledi ilium from the Lesedi Chamber, Rising Star Cave, South Africa

Objectives Homo naledi is represented by abundant remains from the Dinaledi Chamber of the Rising Star Cave system in South Africa. While pelvic elements from the Dinaledi Chamber of the cave are fragmentary, a relatively complete ilium (U.W. 102a–138) was recovered from the Lesedi Chamber. We reconstructed and analyzed the Lesedi ilium, providing qualitative descriptions and quantitative assessment of its morphology and developmental state.Materials and MethodsWe compared the Lesedi ilium to remains from the Dinaledi Chamber, other South African hominin fossils, and an ontogenetic series of human ilia. We used the Dinaledi adults as a guide for reconstructing the Lesedi ilium. To assess development of the Lesedi ilium, we compared immature/mature proportional ilium height for fossils and humans. We used 3D geometric morphometrics (GMs) to examine size and shape variation among this sample.ResultsThe Lesedi ilium showed incipient development of features expressed in adult H. naledi ilia. The proportional height of the Lesedi ilium was within the range of human juveniles between 4–11 years of age. GM analyses showed that the Lesedi ilium had an iliac blade shape similar to those of australopiths and an expanded auricular surface more similar to humans.ConclusionsThe reconstructed Lesedi specimen represents the best preserved ilium of H. naledi, confirming the australopith‐like iliac blade morphology first hypothesized in adult specimens, and establishing that this anatomy was present early in this species' ontogeny. In contrast to australopiths, the Lesedi ilium displays an enlarged sacroiliac joint, the significance of which requires further investigation.

Since when have humans had a soul?

An attempt is made to determine when humans have had a soul. For this purpose, mind and soul are distinguished from each other. This clarification of terms makes it possible to criticise the emergentist view, which assumes that the soul arises naturally from the biological organism. The existence of a soul is inferred from the mental activities of humans, which are directed towards the transcendent. Special significance is given to burials. Burials have been practised for at least 448 000 years. Not only Homo sapiens, but also Homo naledi, Homo heidelbergensis steinheimensis and Homo neanderthalensis buried their dead. Therefore, there is good reason to assume that Homo heidelbergensis and all its descendants possessed (and still possess) a soul. Moreover, one can suppose that Homo erectus and Homo naledi also possessed a soul.Contribution: The clear distinction between the immanent mind and the transcendent soul makes us aware that we humans are beings equally at home in immanence and transcendence. Humans have possessed a soul for a very long time, and not only Homo sapiens but also his ancestors and related species.

A new early hominin calcaneus from Kromdraai (South Africa).

The Kromdraai site in South Africa has yielded numerous early hominin fossils since 1938. As a part of recent excavations within Unit P, a largely complete early hominin calcaneus (KW 6302) was discovered. Due to its role in locomotion, the calcaneus has the potential to reveal important form/function relationships. Here, we describe KW 6302 and analyze its preserved morphology relative to human and nonhuman ape calcanei, as well as calcanei attributed to Australopithecus afarensis, Australopithecus africanus, Australopithecus sediba, Homo naledi, and the Omo calcaneus (either Paranthropus or early Homo). KW 6302 calcaneal morphology is assessed using numerous quantitative metrics including linear measures, calcaneal robusticity index, relative lateral plantar process position, Achilles tendon length reconstruction, and a three-dimensional geometric morphometric sliding semilandmark analysis. KW 6302 exhibits an overall calcaneal morphology that is intermediate between humans and nonhuman apes, although closer to modern humans. KW 6302 possesses many traits that indicate it was likely well-adapted for terrestrial bipedal locomotion, including a relatively flat posterior talar facet and a large lateral plantar process that is similarly positioned to modern humans. It also retains traits that indicate that climbing may have remained a part of its locomotor repertoire, such as a relatively gracile tuber and a large peroneal trochlea. Specimens from Kromdraai have been attributed to either Paranthropus robustus or early Homo; however, there are no definitively attributed calcanei for either genus, making it difficult to taxonomically assign this specimen. KW 6302 and the Omo calcaneus, however, fall outside the range of expected variation for an extant genus, indicating that if the Omo calcaneus was Paranthropus, then KW 6302 would likely be attributed to early Homo (or vice versa).

Explore Paleoanthropology Fieldwork

This classroom exercise utilizes a free mobile virtual reality app to introduce students to (1) the process by which paleoanthropologists find and interpret fossils, (2) the importance of two recent hominin fossil finds in the Cradle of Humankind of South Africa, and (3) the variety of science careers that contribute to paleoanthropological research. Before their virtual field trip, learners are introduced to the Homo naledi and Australopithecus sediba discoveries and to some of the researchers from the team through a collection of online resources. In the app, learners explore and find fossils in the Dinaledi Chamber of Rising Star Cave in South Africa, where the first fossils of H. naledi were found. Postexploration analysis and reflection prompts encourage learners to consider how researchers decide how and where to excavate, which skills are needed to study our human origins, and why this research is important.

Evolution of cranial capacity revisited: A view from the late Middle Pleistocene cranium from Xujiayao, China

The Late Middle Pleistocene hominin fossils from the Xujiayao site in northern China have been closely studied in light of their morphological variability. However, all previous studies have focused on separated cranial fragments. Here, we report the first reconstruction of a fairly complete posterior cranium, Xujiayao 6 (XJY 6), confidently dated to ∼200–160 ka, which facilitated an assessment of its overall cranial size. XJY 6 was reconstructed from three of the original fragments—the PA1486 (No.7/XJY 6a) occipital bone, PA1490 (No.10/XJY 6b) right parietal bone, and PA1498 (No.17/XJY 15) left temporal bone—which originated from the same young adult individual. The XJY 6 endocranial capacity, estimated by measuring endocranial volume, was estimated using multiple regression formulae derived from ectocranial and endocranial measurements on select samples of Pleistocene hominins and recent modern humans. The results indicate that the larger pooled sample of both Pleistocene and recent modern humans was more robust for the endocranial capacity estimate. Based on the pooled sample using the ectocranial and endocranial measurements, we conservatively estimate the XJY 6 endocranial volume to be ∼1700 cm3 with a 95% confidence interval of 1555–1781 cm3. This is close to Xuchang 1, which dates to 125–105 ka and whose endocranial volume is ∼1800 cm3. Thus, XJY 6 provides the earliest evidence of a brain size that falls in the upper range of Neanderthals and modern Homo sapiens. XJY 6, together with Xuchang 1, Homo floresiensis, Homo luzonensis, and Homo naledi, challenge the general pattern that brain size gradually increases over geological time. This study also finds that hominin brain size expansion occurred at different rates across time and space.

Characterizing the body morphology of the first metacarpal in the Homininae using 3D geometric morphometrics

AbstractObjectivesThe morphological characteristics of the thumb are of particular interest due to its fundamental role in enhanced manipulation. Despite its possible importance regarding this issue, the body of the first metacarcapal (MC1) has not been fully characterized using morphometrics. This could provide further insights into its anatomy, as well as its relationship with manipulative capabilities. Hence, this study quantifies the shape of the MC1's body in the extant Homininae and some fossil hominins to provide a better characterization of its morphology.Materials and methodsThe sample includes MC1s of modern humans (n = 42), gorillas (n = 27), and chimpanzees (n = 30), as well as Homo neanderthalensis, Homo naledi, and Australopithecus sediba. 3D geometric morphometrics were used to quantify the shape of MC1's body.ResultsThe results show a clear distinction among the three extant genera. H. neanderthalensis mostly falls within the modern human range of variation. H. naledi varies slightly from modern humans, although also showing some unique trait combination, whereas A. sediba varies to an even greater extent. When classified using a discriminant analysis, the three fossils are categorized within the Homo group.ConclusionThe modern human MC1 is characterized by a distinct suite of traits, not present to the same extent in the great apes, that are consistent with an ability to use forceful precision grip. This morphology was also found to align very closely with that of H. neanderthalensis. H. naledi shows a number of human‐like adaptations, while A. sediba presents a mix of both derived and more primitive traits.