Journal of Anthropological Sciences最新文献

KNM-OG 45500 is a hominin fossil composed of parts of a frontal bone, left temporal bone, and cranial vault pieces. Since its discovery along the Olorgesailie Formation (Kenya) in 2003, it has been associated with the Homo erectus hypodigm. The specimen, derived from a geological context dated to ca. 900 Ka BP, has been described as a very small individual of probable female sex. However, despite its status as an important hominin specimen, it has not been used in a quantitative comparative framework because of its fragmentary condition. Here, we undertake a virtual reconstruction of the better-preserved fragment, the frontal bone. We additionally apply geometric morphometric analyses, using a geographically diverse fossil and modern human sample, in order to investigate the morphological affinities of KNM-OG 45500. Our results show that the frontal shape of KNM-OG 45500 exhibits similarities with Early Pleistocene fossils from Eurasia and Africa that are assigned to H. erectus sensu lato (s.l.). Its size, on the other hand, is notably smaller than most other Homo erectus fossils and modern humans and similar to the specimens from Dmanisi (Georgia) and to Homo naledi. Taken together, our analyses of the frontal bone suggest a taxonomic attribution of KNM-OG 45500 to H. erectus s.l. and extend even further the range of size variability associated with this taxon around 900 Ka BP.

Recent finds in hominin fossil environments place the transition to terrestriality in a wooded or forested habitat. Therefore, forest-dwelling apes can aid in understanding this important evolutionary transition. Sex differences in ape locomotion have been previously attributed to sexual dimorphism or ecological niche differences between males and females. This study examined the hypothesis that differential advantages of terrestrial travel may impact mating success in male bonobos. We examined whether males are more terrestrial when there are mating benefits for fast travel. We analyzed behavioral data on wild bonobos over a ten-month period in the Lomako Forest, DRC and examined the proportion of time spent at lower heights compared to higher heights between adult females and males relative to their location to feeding contexts with high mating frequencies. We found a significant interaction between sex and height class away from food patches (F=4.65, df =1, p <0.05) such that females were primarily arboreal whereas there was no difference between males across height classes. However, there was also a significant interaction between sex and height class (F =29.35, df =1, p <0.0001) for adults traveling near or entering a food patch. Males often arrived at food patches terrestrially and females arrived almost exclusively arboreally. We found a significant difference between the expected and observed distribution of matings by food patch context (G =114.36, df =4, p <0.0001) such that most mating occurred near or in a food patch. These results suggest that males may travel terrestrially to arrive at food patches before cohesive parties of females arrive arboreally, in order to compete with other males for mating access to these females. Such intrasexual selection for sex differences in locomotion may be important in considerations of the evolution of locomotion strategies in hominins in a forested environment.

Ambiguities within species description and identification may compromise research validity. Species identification has typically been based upon morphological characteristics, yet recent technological advances have led to identifications achieved via DNA approaches, including DNA barcoding. DNA barcoding studies typically use cytochrome c oxidase subunit I (COI) as the proposed universal molecular marker for animals. Here, we test 12 mitochondrial protein coding genes for the presence of a clear barcoding gap allowing us to unequivocally define species. Using the African Great Apes as our model group, we assess this at the species (Pan troglodytes), genus (Pan) and family (Hominidae) level. Based on 279 complete mitochondrial genomes, sequences were partitioned by gene for analysis and pairwise distances were calculated. No barcoding gap was observed at the within species level, i.e., the four recognised chimpanzee taxa were not distinguishable through DNA barcoding. However, NADH dehydrogenase subunit 5 (ND5) and cytochrome c oxidase subunit II (COII) produce the largest barcoding gaps at the genus (ND5 2%, COII 0.5%) and family (ND5 1.5%, COII 0.5%) level. Rather than focusing on COI, our analysis suggests that these two genes may be more, or at least as, appropriate markers in primate species delineation, with uses in the identification of extinct and extant species. Further use may be beneficial to taxonomists, providing additional evidence and new insights for these morphologically similar species.

In paleoanthropological literature, the use of the term "mosaic" (mosaic evolution, mosaic trait, mosaic species, and so on) is becoming more and more frequent. In order to promote a clarification of the use of the concept in literature, we propose here a classification in three different meanings of the notion of mosaic in human evolution: 1) morphological (inter-specific and intra-specific) instability in a certain phase of a branched phylogeny; 2) multiple trajectories and versions of the same adaptive trait in a branched phylogeny; 3) the trait itself as a complex mosaic of sub-traits with different phylogenetic stories (as is the case in language). We argue that the relevance of such mosaic patterns needs a macro-evolutionary interpretation, which takes into consideration the interaction between general selective pressures (promoting different versions of the same adaptation) and a cladogenetic approach in which speciation played a crucial role, due to ecological instability, habitat fragmentation, and geographical dispersals in human evolution.

Scenarios for the dispersal of Homo sapiens in Southern Europe and in the Mediterranean basin have been uncertain, given the scarceness of osteological samples and the simplicity of the proposed archaeologically-based settlement hypotheses. According to available data, the first anatomically modern humans entered Sicily during the Late Pleistocene, coming from the Italian peninsula. A presumably small Late Epigravettian population colonised coastal sites. Later, North-Western archaeological horizons gave hospitality to a significant Mesolithic expansion. In order to verify a hypothesis of continuity in the peopling of the island, we analyzed Sicilian skulls from the Late Epigravettian site of San Teodoro, Eastern Sicily (AMS 14C dated at 14,500 BP) and from the Mesolithic period (14C dated from 9,500 to 8,500 BP) coming from various sites (Uzzo, Molara, Grotta d'Oriente) located on the North Western coast of the island. The aims were to test the biological variability through time within the island as well as to evaluate the relationships of Sicilian Pleistocene hunter-gatherers with Old World populations. We also evaluated the Sicilian Mesolithic uniformity especially between the Uzzo and Grotta d'Oriente sites, given their vicinity and accessibility during the Early Holocene. We applied 3D geometric morphometric methods to assess shape variation as well as geographic and diachronic morphological patterns. All analyzed specimens, plus a comparative sample from the Old World dated from the Upper Paleolithic to recent periods, were transformed in digital images and standard craniofacial landmarks were extracted from the 3D models. Our results underline a high variability among the Mesolithic specimens, as well as a large craniometric distance from the presumed founder Paleolithic settler representatives (San Teodoro specimens) that have closer morphological affinities with other European Upper Paleolithic specimens.

North Africa features some of the earliest manifestations of the Middle Stone Age (MSA) and fossils of our species, Homo sapiens, as well as early examples of complex culture and the long distance transfer of exotic raw materials. As they are elsewhere, lithics (i.e., stone tools) present by far the most abundant source of information on this cultural period. Given the importance of North Africa in human origins, understanding the character and distribution of MSA lithics is therefore crucial, as they shed light on early human behaviour and culture. However, the lithics of the North African MSA are poorly understood, and their technological variability is frequently obfuscated by regionally specific nomenclatures, often repeated without criticism, and diverse methods of analysis that are often incompatible. Characterising dynamic technological innovations as well as apparent technological stasis remains challenging, and many narratives have not been tested quantitatively. This significantly problematizes hypotheses of human evolution and dispersals invoking these data that extend beyond North Africa. This paper therefore presents a description of the lithics of the North African MSA, including their technological characteristics, chronology, spatial distribution and associated research traditions. A range of interpretations concerning early H. sapiens demography in North Africa are then re-evaluated in the light of this review, and the role and power of lithic data to contribute to such debates is critically assessed.