Browsing by Author "Braun, David R."
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- A missing piece of the Papio puzzle: Gorongosa baboon phenostructure and intrageneric relationshipsPublication . Martinez, Felipe I.; Capelli, Cristian; Ferreira da Silva, Maria J.; Aldeias, Vera; Alemseged, Zeresenay; Archer, William; Bamford, Marion; Biro, Dora; Bobe, Rene; Braun, David R.; Habermann, Jörg M.; Luedecke, Tina; Madiquida, Hilario; Mathe, Jacinto; Negash, Enquye; Paulo, Luis M.; Pinto, Maria; Stalmans, Marc; Tata, Frederico; Carvalho, SusanaMost authors recognize six baboon species: hamadryas (Papio hamadryas), Guinea (Papio papio), olive (Papio anubis), yellow (Papio cynocephalus), chacma (Papio ursinus), and Kinda (Papio kindae). However, there is still debate regarding the taxonomic status, phylogenetic relationships, and the amount of gene flow occurring between species. Here, we present ongoing research on baboon morphological diversity in Gorongosa National Park (GNP), located in central Mozambique, south of the Zambezi River, at the southern end of the East African Rift System. The park exhibits outstanding ecological diversity and hosts more than 200 baboon troops. Gorongosa National Park baboons have previously been classified as chacma baboons (P. ursinus). In accordance with this, two mtDNA samples from the park have been placed in the same mtDNA Glade as the northern chacma baboons. However, GNP baboons exhibit morphological features common in yellow baboons (e.g., yellow fur color), suggesting that parapatric gene flow between chacma and yellow baboons might have occurred in the past or could be ongoing. We investigated the phenostructure of the Gorongosa baboons using two approaches: 1) description of external phenotypic features, such as coloration and body size, and 2) 3D geometric morphometric analysis of 43 craniofacial landmarks on 11 specimens from Gorongosa compared to a pan-African sample of 352 baboons. The results show that Gorongosa baboons exhibit a mosaic of features shared with southern P. cynocephalus and P. ursinus griseipes. The GNP baboon phenotype fits within a geographic clinal pattern of replacing allotaxa. We put forward the hypothesis of either past and/or ongoing hybridization between the gray-footed chacma and southern yellow baboons in Gorongosa or an isolation-by-distance scenario in which the GNP baboons are geographically and morphologically intermediate. These two scenarios are not mutually exclusive. We highlight the potential of baboons as a useful model to understand speciation and hybridization in early human evolution. (C) 2019 Elsevier Ltd. All rights reserved.
- Carbon, nitrogen, and oxygen stable isotopes in modern tooth enamel: A case study from Gorongosa National Park, central MozambiquePublication . Lüdecke, Tina; Leichliter, Jennifer N.; Aldeias, Vera; Bamford, Marion K.; Biro, Dora; Braun, David R.; Capelli, Cristian; Cybulski, Jonathan D.; Duprey, Nicolas N.; Ferreira da Silva, Maria J.; Foreman, Alan D.; Habermann, Jörg M.; Haug, Gerald H.; Martínez, Felipe I.; Mathe, Jacinto; Mulch, Andreas; Sigman, Daniel M.; Vonhof, Hubert; Bobe, Rene; Carvalho, Susana; Martínez-García, AlfredoThe analyses of the stable isotope ratios of carbon (delta C-13), nitrogen (delta N-15), and oxygen (delta O-18) in animal tissues are powerful tools for reconstructing the feeding behavior of individual animals and characterizing trophic interactions in food webs. Of these biomaterials, tooth enamel is the hardest, most mineralized vertebrate tissue and therefore least likely to be affected by chemical alteration (i.e., its isotopic composition can be preserved over millions of years), making it an important and widely available archive for biologists and paleontologists. Here, we present the first combined measurements of delta C-13, delta N-15, and delta O-18 in enamel from the teeth of modern fauna (herbivores, carnivores, and omnivores) from the well-studied ecosystem of Gorongosa National Park (GNP) in central Mozambique. We use two novel methods to produce high-precision stable isotope enamel data: (i) the "oxidation-denitrification method," which permits the measurement of mineral-bound organic nitrogen in tooth enamel (delta N-15(enamel)), which until now, has not been possible due to enamel's low organic content, and (ii) the "cold trap method," which greatly reduces the sample size required for traditional measurements of inorganic delta C-13(enamel) and delta O-18(enamel) (from >= 0.5 to <= 0.1 mg), permitting analysis of small or valuable teeth and high-resolution serial sampling of enamel. The stable isotope results for GNP fauna reveal important ecological information about the trophic level, dietary niche, and resource consumption. delta N-15(enamel) values clearly differentiate trophic level (i.e., carnivore delta N-15(enamel) values are 4.0 parts per thousand higher, on average, than herbivores), delta C-13(enamel) values distinguish C-3 and/or C-4 biomass consumption, and delta O-18(enamel) values reflect local meteoric water (delta O-18(water)) in the park. Analysis of combined carbon, nitrogen, and oxygen stable isotope data permits geochemical separation of grazers, browsers, omnivores, and carnivores according to their isotopic niche, while mixed-feeding herbivores cannot be clearly distinguished from other dietary groups. These results confirm that combined C, N, and O isotope analyses of a single aliquot of tooth enamel can be used to reconstruct diet and trophic niches. Given its resistance to chemical alteration, the analysis of these three isotopes in tooth enamel has a high potential to open new avenues of research in (paleo)ecology and paleontology.
- Chimpanzee wooden tool analysis advances the identification of percussive technologyPublication . Luncz, Lydia V.; Braun, David R.; Marreiros, Joao; Bamford, Marion; Zeng, Chen; Pacome, Serge Soiret; Junghenn, Patrick; Buckley, Zachary; Yao, Xinyu; Carvalho, SusanaThe ability of humans to mediate environmental variation through tool use is likely the key to our success. However, our current knowledge of early cultural evolution derives almost exclusively from studies of stone tools and fossil bones found in the archaeological record. Tools made of plants are intrinsically perishable, and as such are almost entirely absent in the early record of human material culture. Modern human societies as well as nonhuman primate species use plant materials for tools far more often than stone, suggesting that current archaeological data are missing a substantial component of ancient technology. Here, we develop methods that quantify internal and external damage pattern in percussive wooden tools of living primates. Our work shows that the inflicted damage is irreversible, potentially persisting throughout fossilization processes. This research presents opportunities to investigate organic artifacts, a significant and highly neglected aspect of technological evolution within the Primate order.
- Did erly pleistocene hominins control hammer strike angles when making stone tools?Publication . Li, Li; Reeves, Jonathan S.; Lin, Sam C.; Braun, David R.; McPherron, Shannon P.In the study of Early Pleistocene stone artifacts, researchers have made considerable progress in reconstructing the technical decisions of hominins by examining various aspects of lithic technology, such as reduction sequences, hammer selection, platform preparation, core management, and raw material selection. By comparison, our understanding of the ways in which Early Pleistocene hominins controlled the delivery and application of percussive force during flaking remains limited. In this study, we focus on a key aspect of force delivery in stone knapping, namely the hammerstone striking angle (or the angle of blow), which has been shown to play a significant role in determining the knapping outcome. Using a dataset consists of 12 Early Pleistocene flake assemblages dated from 1.95 Ma to 1.4 Ma, we examined temporal patterns of the hammer striking angle by quantifying the bulb angle, a property of the flake's Hertzian cone that reflects the hammer striking angle used in flake production. We further included a Middle Paleolithic flake assemblage as a point of comparison from a later time period. In the Early Pleistocene dataset, we observed an increased association between the bulb angle and other flake variables related to flake size over time, a pattern similarly found in the Middle Paleolithic assemblage. These findings suggest that, towards the OldowaneAcheulean transition, hominins began to systematically adjust the hammer striking angle in accordance with platform variables to detach flakes of different sizes more effectively, implying the development of a more comprehensive understanding of the role of the angle of blow in flake formation by similar to 1.5 Ma.
- Earliest known Oldowan Artifacts at > 2.58 Ma from Ledi-Geraru, Ethiopia, highlight early technological diversityPublication . Braun, David R.; Aldeias, Vera; Archer, William A.; Ramon Arrowsmith, J.; Baraki, Niguss; Campisano, Christopher J.; Deino, Alan L.; DiMaggio, Erin N.; Dupont-Nivet, Guillaume; Engda, Blade; Feary, David A.; Garello, Dominique I.; Kerfelew, Zenash; McPherron, Shannon P.; Patterson, David B.; Reeves, Jonathan S.; Thompson, Jessica C.; Reed, Kaye E.The manufacture of flaked stone artifacts represents a major milestone in the technology of the human lineage. Although the earliest production of primitive stone tools, predating the genus Homo and emphasizing percussive activities, has been reported at 3.3 million years ago (Ma) from Lomekwi, Kenya, the systematic production of sharp-edged stone tools is unknown before the 2.58–2.55 Ma Oldowan assemblages from Gona, Ethiopia. The organized production of Oldowan stone artifacts is part of a suite of characteristics that is often associated with the adaptive grade shift linked to the genus Homo. Recent discoveries from Ledi-Geraru (LG), Ethiopia, place the first occurrence of Homo ∼250 thousand years earlier than the Oldowan at Gona. Here, we describe a substantial assemblage of systematically flaked stone tools excavated in situ from a stratigraphically constrained context [Bokol Dora 1, (BD 1) hereafter] at LG bracketed between 2.61 and 2.58 Ma. Although perhaps more primitive in some respects, quantitative analysis suggests the BD 1 assemblage fits more closely with the variability previously described for the Oldowan than with the earlier Lomekwian or with stone tools produced by modern nonhuman primates. These differences suggest that hominin technology is distinctly different from generalized tool use that may be a shared feature of much of the primate lineage. The BD 1 assemblage, near the origin of our genus, provides a link between behavioral adaptations—in the form of flaked stone artifacts—and the biological evolution of our ancestors.
- Ecosystem engineering in the Quaternary of the West Coast of South AfricaPublication . Braun, David R.; Faith, John Tyler; Douglass, Matthew J.; Davies, Benjamin; Power, Mitchel J.; Aldeias, Vera; Conard, Nicholas J.; Cutts, Russell; DeSantis, Larisa R. G.; Dupont, Lydie M.; Esteban, Irene; Kandel, Andrew W.; Levin, Naomi E.; Luyt, Julie; Parkington, John; Pickering, Robyn; Quick, Lynne; Sealy, Judith; Stynder, DeanoDespite advances in our understanding of the geographic and temporal scope of the Paleolithic record, we know remarkably little about the evolutionary and ecological consequences of changes in human behavior. Recent inquiries suggest that human evolution reflects a long history of interconnections between the behavior of humans and their surrounding ecosystems (e.g., niche construction). Developing expectations to identify such phenomena is remarkably difficult because it requires understanding the multi-generational impacts of changes in behavior. These long-term dynamics require insights into the emergent phenomena that alter selective pressures over longer time periods which are not possible to observe, and are also not intuitive based on observations derived from ethnographic time scales. Generative models show promise for probing these potentially unexpected consequences of human-environment interaction. Changes in the uses of landscapes may have long term implications for the environments that hominins occupied. We explore other potential proxies of behavior and examine how modeling may provide expectations for a variety of phenomena.
- Genomic variation in baboons from central Mozambique unveils complex evolutionary relationships with other Papio speciesPublication . Santander, Cindy; Molinaro, Ludovica; Mutti, Giacomo; Martínez, Felipe I.; Mathe, Jacinto; Ferreira da Silva, Maria J.; Caldon, Matteo; Oteo-Garcia, Gonzalo; Aldeias, Vera; Archer, Will; Bamford, Marion; Biro, Dora; Bobe, René; Braun, David R.; Hammond, Philippa; Lüdecke, Tina; Pinto, Maria J.; Meira Paulo, Luis; Stalmans, Marc; Regala, Frederico; Bertolini, Francesco; Moltke, Ida; Raveane, Alessandro; Pagani, Luca; Carvalho, Susana; Capelli, CristianBackground Gorongosa National Park in Mozambique hosts a large population of baboons, numbering over 200 troops. Gorongosa baboons have been tentatively identified as part of Papio ursinus on the basis of previous limited morphological analysis and a handful of mitochondrial DNA sequences. However, a recent morphological and morphometric analysis of Gorongosa baboons pinpointed the occurrence of several traits intermediate between P. ursinus and P. cynocephalus, leaving open the possibility of past and/or ongoing gene flow in the baboon population of Gorongosa National Park. In order to investigate the evolutionary history of baboons in Gorongosa, we generated high and low coverage whole genome sequence data of Gorongosa baboons and compared it to available Papio genomes. Results We confirmed that P. ursinus is the species closest to Gorongosa baboons. However, the Gorongosa baboon genomes share more derived alleles with P. cynocephalus than P. ursinus does, but no recent gene flow between P. ursinus and P. cynocephalus was detected when available Papio genomes were analyzed. Our results, based on the analysis of autosomal, mitochondrial and Y chromosome data, suggest complex, possibly male-biased, gene flow between Gorongosa baboons and P. cynocephalus, hinting to direct or indirect contributions from baboons belonging to the “northern” Papio clade, and signal the presence of population structure within P. ursinus. Conclusions The analysis of genome data generated from baboon samples collected in central Mozambique highlighted a complex set of evolutionary relationships with other baboons. Our results provided new insights in the population dynamics that have shaped baboon diversity.
- Gorongosa by the sea: First Miocene fossil sites from the Urema Rift, central Mozambique, and their coastal paleoenvironmental and paleoecological contextsPublication . Habermann, Jörg M.; Alberti, Matthias; Aldeias, Vera; Alemseged, Zeresenay; Archer, Will; Bamford, Marion; Biro, Dora; Braun, David R.; Capelli, Cristian; Cunha, Eugenia; da Silva, Maria Ferreira; Luedecke, Tina; Madiquida, Hilario; Martinez, Felipe I.; Mathe, Jacinto; Negash, Enquye; Paulo, Luis M.; Pinto, Maria; Stalmans, Marc; Regala, Frederico Tata; Wynn, Jonathan G.; Bobe, Rene; Carvalho, SusanaThe East African Rift System (EARS) has played a central role in our understanding of human origins and vertebrate evolution in the late Cenozoic of Africa. However, the distribution of fossil sites along the rift is highly biased towards its northern extent, and the types of paleoenvironments are primarily restricted to fluvial and lacustrine settings. Here we report the discovery of the first fossil sites from the Urema Rift at Gorongosa National Park (central Mozambique) at the southern end of the EARS, and reconstruct environmental contexts of the fossils. In situ and surface fossils from the lower member of the Mazamba Formation, estimated to be of Miocene age, comprise mammals, reptiles, fishes, invertebrates, palms, and dicot trees. Fossil and geological evidence indicates a coastal-plain paleoenvironmental mosaic of riverine forest/woodland and estuarine habitats that represent the first coastal biomes identified in the Neogene EARS context. Receiving continental sediment from source terranes west of today's Urema Graben, estuarine sequences accumulated prior to rifting as compound incised-valley fills on a low-gradient coastal plain following transgression. Modern environmental analogues are extremely productive habitats for marine and terrestrial fauna, including primates. Thus, our discoveries raise the possibility that the Miocene coastal landscapes of Gorongosa were ecologically-favorable habitats for primates, providing relatively stable maritime climate and ecosystem conditions, year-round freshwater availability, and food both from terrestrial and marine sources. The emerging fossil record from Gorongosa is beginning to fill an important gap in the paleobiogeography of Africa as no fossil sites of Neogene age have previously been reported from the southernmost part of the EARS. Furthermore, this unique window into past continental-margin ecosystems of central Mozambique may allow us to test key paleobiogeographic hypotheses during critical periods of primate evolution.
- Introduction: Hominin paleobiology in the early Pleistocene Okote Member, Koobi Fora Formation, KenyaPublication . Bobe, Rene; Braun, David R.; Behrensmeyer, Anna K.; Harris, John W. K.
- Pliocene hominins from East Turkana were associated with mesic environments in a semiarid basinPublication . Villaseñor, Amelia; Uno, Kevin T.; Kinyanjui, Rahab N.; Behrensmeyer, Anna K.; Bobe, René; Advokaat, Eldert L.; Bamford, Marion; Carvalho, Susana; Hammond, Ashley S.; Palcu, Dan V.; Sier, Mark J.; Ward, Carol V.; Braun, David R.During the middle Pliocene (similar to 3.8-3.2 Ma), both Australopithecus afarensis and Kenyanthropus platyops are known from the Turkana Basin, but between 3.60 and 3.44 Ma, most hominin fossils are found on the west side of Lake Turkana. Here, we describe a new hominin locality (ET03-166/168, Area 129) from the east side of the lake, in the Lokochot Member of the Koobi Fora Formation (3.60-3.44 Ma). To reconstruct the paleoecology of the locality and its surroundings, we combine information from sedimentology, the relative abundance of associated mammalian fauna, phytoliths, and stable isotopes from plant wax biomarkers, pedogenic carbonates, and fossil tooth enamel. The combined evidence provides a detailed view of the local paleoenvironment occupied by these Pliocene hominins, where a biodiverse community of primates, including hominins, and other mammals inhabited humid, grassy woodlands in a fluvial floodplain setting. Between <3.596 and 3.44 Ma, increases in woody vegetation were, at times, associated with increases in arid-adapted grasses. This suggests that Pliocene vegetation included woody species that were resilient to periods of prolonged aridity, resembling vegetation structure in the Turkana Basin today, where arid-adapted woody plants are a significant component of the ecosystem. Pedogenic carbonates indicate more woody vegetation than other vegetation proxies, possibly due to differences in temporospatial scale and ecological biases in preservation that should be accounted for in future studies. These new hominin fossils and associated multiproxy paleoenvironmental indicators from a single locale through time suggest that early hominin species occupied a wide range of habitats, possibly including wetlands within semiarid landscapes. Local-scale paleoecological evidence from East Turkana supports regional evidence that middle Pliocene eastern Africa may have experienced large-scale, climate-driven periods of aridity. This information extends our understanding of hominin environments beyond the limits of simple wooded, grassy, or mosaic environmental descriptions. (c) 2023 Elsevier Ltd. All rights reserved.