Browsing by Author "McPherron, Shannon P."
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- A C-14 chronology for the Middle to Upper Palaeolithic transition at Bacho Kiro Cave, BulgariaPublication . Fewlass, Helen; Talamo, Sahra; Wacker, Lukas; Kromer, Bernd; Tuna, Thibaut; Fagault, Yoann; Bard, Edouard; McPherron, Shannon P.; Aldeias, Vera; Maria, Raquel; Martisius, Naomi L.; Paskulin, Lindsay; Rezek, Zeljko; Sinet-Mathiot, Virginie; Sirakova, Svoboda; Smith, Geoffrey M.; Spasov, Rosen; Welker, Frido; Sirakov, Nikolay; Tsanova, Tsenka; Hublin, Jean-JacquesThe stratigraphy at Bacho Kiro Cave, Bulgaria, spans the Middle to Upper Palaeolithic transition, including an Initial Upper Palaeolithic (IUP) assemblage argued to represent the earliest arrival of Upper Palaeolithic Homo sapiens in Europe. We applied the latest techniques in C-14 dating to an extensive dataset of newly excavated animal and human bones to produce a robust, high-precision radiocarbon chronology for the site. At the base of the stratigraphy, the Middle Palaeolithic (MP) occupation dates to >51,000 yr bp. A chronological gap of over 3,000 years separates the MP occupation from the occupation of the cave by H. sapiens, which extends to 34,000 cal bp. The extensive IUP assemblage, now associated with directly dated H. sapiens fossils at this site, securely dates to 45,820-43,650 cal bp (95.4% probability), probably beginning from 46,940 cal bp (95.4% probability). The results provide chronological context for the early occupation of Europe by Upper Palaeolithic H. sapiens. A new radiocarbon chronology for the Middle to Upper Palaeolithic transition at the Bulgarian site of Bacho Kiro reveals Homo sapiens-associated sediments as early as 46,940 yr bp.
- Comparing extraction method efficiency for high-throughput palaeoproteomic bone species identificationPublication . Mylopotamitaki, Dorothea; Harking, Florian S.; Taurozzi, Alberto J.; Fagernäs, Zandra; Godinho, Ricardo Miguel; Smith, Geoff M.; Weiss, Marcel; Schüler, Tim; McPherron, Shannon P.; Meller, Harald; Cascalheira, João; Bicho, Nuno; Olsen, Jesper V.; Hublin, Jean-Jacques; Welker, FridoHigh-throughput proteomic analysis of archaeological skeletal remains provides information about past fauna community compositions and species dispersals in time and space. Archaeological skeletal remains are a finite resource, however, and therefore it becomes relevant to optimize methods of skeletal proteome extraction. Ancient proteins in bone specimens can be highly degraded and consequently, extraction methods for well-preserved or modern bone might be unsuitable for the processing of highly degraded skeletal proteomes. In this study, we compared six proteomic extraction methods on Late Pleistocene remains with variable levels of proteome preservation. We tested the accuracy of species identification, protein sequence coverage, deamidation, and the number of post-translational modifications per method. We find striking differences in obtained proteome complexity and sequence coverage, highlighting that simple acid-insoluble proteome extraction methods perform better in highly degraded contexts. For well-preserved specimens, the approach using EDTA demineralization and protease-mix proteolysis yielded a higher number of identified peptides. The protocols presented here allowed protein extraction from ancient bone with a minimum number of working steps and equipment and yielded protein extracts within three working days. We expect further development along this route to benefit large-scale screening applications of relevance to archaeological and human evolution research.
- 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.
- Fossils from Mille-Logya, Afar, Ethiopia, elucidate the link between Pliocene environmental changes and Homo originsPublication . Alemseged, Zeresenay; Wynn, Jonathan G.; Geraads, Denis; Reed, Denne; Andrew Barr, W.; Bobe, Rene; McPherron, Shannon P.; Deino, Alan; Alene, Mulugeta; J. Sier, Mark; Roman, Diana; Mohan, JosephSeveral hypotheses posit a link between the origin of Homo and climatic and environmental shifts between 3 and 2.5 Ma. Here we report on new results that shed light on the interplay between tectonics, basin migration and faunal change on the one hand and the fate of Australopithecus afarensis and the evolution of Homo on the other. Fieldwork at the new Mille-Logya site in the Afar, Ethiopia, dated to between 2.914 and 2.443 Ma, provides geological evidence for the northeast migration of the Hadar Basin, extending the record of this lacustrine basin to Mille-Logya. We have identified three new fossiliferous units, suggesting in situ faunal change within this interval. While the fauna in the older unit is comparable to that at Hadar and Dikika, the younger units contain species that indicate more open conditions along with remains of Homo. This suggests that Homo either emerged from Australopithecus during this interval or dispersed into the region as part of a fauna adapted to more open habitats.
- How did hominins adapt to Ice Age Europe without fire?Publication . Dibble, Harold L.; Abodolahzadeh, Aylar; Aldeias, Vera; Goldberg, Paul; McPherron, Shannon P.; Sandgathe, Dennis M.Analyses of archaeological material recovered from several Middle Paleolithic sites in southwest France have provided strong corroborating data on Neanderthal use of fire. Both direct and indirect data show that Neanderthals in this region were frequently and/or intensively using fire during warmer periods, but such evidence declines significantly in occupations that took place during colder periods. One possible explanation for this pattern is that it reflects the inability of Western European Neanderthals to make fire, simply because natural sources of fire occur much more frequently during warmer climatic periods. Regardless of the explanation, the long periods of diminished evidence of fire shows that, unlike modern humans, these hominins were not obligate fire users, and this fact in itself raises important questions of how they adapted, physiologically and/or technologically, to the generally harsh glacial conditions of the middle latitude of Europe and to reduced energy returns typical of raw food. As a corollary, it also raises questions regarding their need for and use of fire during the warmer periods.
- Measuring spatial structure in time-averaged deposits insights from Roc de Marsal, FrancePublication . Reeves, Jonathan S.; McPherron, Shannon P.; Aldeias, Vera; Dibble, Harold L.; Goldberg, Paul; Sandgathe, Dennis; Turq, AlainThe use of space, both at the landscape and the site level, is considered an important aspect of hominin adaptations that changed through time. At the site level, spatial analyses are typically conducted on deposits thought to have a high degree of temporal resolution. Sites with highly time-averaged deposits are viewed as inferior for these analyses because repeated site visits obscure individual behavioral events. To the contrary, here, we take the view that behaviors that repeat themselves in a spatially structured way through time are exactly the kinds of behaviors that are potentially significant at an evolutionary timescale. In this framework, time averaging is seen not as a hindrance but rather as a necessary condition for viewing meaningful behavior. To test whether such patterning is visible in time-averaged deposits, we use spatial statistics to analyze a number of indices designed to measure lithic production, use and discard behaviors in a multi-layer, late Neandertal cave site in southwest France. We find that indeed some such patterning does exist, and thus sites with highly time-averaged deposits have the potential to contribute to our understanding of how hominin use of space varied through time. This is useful because a great many archaeological sites have highly time-average deposits. Interpreting the spatial patterning will likely require modeling to create expectations in time-averaged and likely emergent contexts such as these.
- Reconstructing Late Pleistocene paleoclimate at the scale of human behavior: an example from the Neandertal occupation of La Ferrassie (France)Publication . Pederzani, Sarah; Aldeias, Vera; Dibble, Harold L.; Goldberg, Paul; Hublin, Jean-Jacques; Madelaine, Stéphane; McPherron, Shannon P.; Sandgathe, Dennis; Steele, Teresa E.; Turq, Alain; Britton, KateExploring the role of changing climates in human evolution is currently impeded by a scarcity of climatic information at the same temporal scale as the human behaviors documented in archaeological sites. This is mainly caused by high uncertainties in the chronometric dates used to correlate long-term climatic records with archaeological deposits. One solution is to generate climatic data directly from archaeological materials representing human behavior. Here we use oxygen isotope measurements of Bos/Bison tooth enamel to reconstruct summer and winter temperatures in the Late Pleistocene when Neandertals were using the site of La Ferrassie. Our results indicate that, despite the generally cold conditions of the broader period and despite direct evidence for cold features in certain sediments at the site, Neandertals used the site predominantly when climatic conditions were mild, similar to conditions in modern day France. We suggest that due to millennial scale climate variability, the periods of human activity and their climatic characteristics may not be representative of average conditions inferred from chronological correlations with long-term climatic records. These results highlight the importance of using direct routes, such as the high-resolution archives in tooth enamel from anthropogenically accumulated faunal assemblages, to establish climatic conditions at a human scale.
- Subarctic climate for the earliest Homo sapiens in EuropePublication . Pederzani, Sarah; Britton, Kate; Aldeias, Vera; Bourgon, Nicolas; Fewlass, Helen; Lauer, Tobias; McPherron, Shannon P.; Rezek, Zeljko; Sirakov, Nikolay; Smith, Geoff M.; Spasov, Rosen; Tran, N.-Han; Tsanova, Tsenka; Hublin, Jean-JacquesThe expansion of Homo sapiens across Eurasia marked a major milestone in human evolution that would eventually lead to our species being found across every continent. Current models propose that these expansions occurred only during episodes of warm climate, based on age correlations between archaeological and climatic records. Here, we obtain direct evidence for the temperatures faced by some of these humans through the oxygen isotope analysis of faunal remains from Bacho Kiro Cave, Bulgaria, the earliest clear record of H. sapiens in Europe. The results indicate that humans ∼45,000 years ago experienced subarctic climates with far colder climatic conditions than previously suggested. This demonstrates that the early presence of H. sapiens in Europe was not contingent on warm climates. Our results necessitate the revision of key models of human expansion and highlight the need for a less deterministic role of climate in the study of our evolutionary history.
- Subsistence behavior during the Initial Upper Paleolithic in Europe: site use, dietary practice, and carnivore exploitation at Bacho Kiro Cave (Bulgaria)Publication . Smith, Geoff M.; Spasov, Rosen; Martisius, Naomi L.; Sinet-Mathiot, Virginie; Aldeias, Vera; Rezek, Zeljko; Ruebens, Karen; Pederzani, Sarah; McPherron, Shannon P.; Sirakova, Svoboda; Sirakov, Nikolay; Tsanova, Tsenka; Hublin, Jean-JacquesThe behavioral dynamics underlying the expansion of Homo sapiens into Europe remains a crucial topic in human evolution. Owing to poor bone preservation, past studies have strongly focused on the Initial Upper Paleolithic (IUP) stone tool record. Recent excavations and extensive radiocarbon dating at Bacho Kiro Cave (Bulgaria) pushed back the arrival of IUP H. sapiens into Europe to ca. 45,000 years ago. This site has exceptional bone preservation, and we present the study of 7431 faunal remains from across two IUP layers (I and J) and one Middle Paleolithic layer (K). We identified a shift in site use and occupation intensity through time, marked by increased find density and human modifications in Layer I. Alongside a decrease in carnivore presence and seasonality data demonstrating human presence in all seasons, this indicates a more frequent or prolonged occupation of the site by IUP groups. Contrarily, the dietary focus across the IUP and Middle Paleolithic layers is similar, centered on the exploitation of species from a range of habitats including Bos/Bison, Cervidae, Equidae, and Caprinae. While body parts of large herbivores were selectively transported into the site, the bear remains suggest that these animals died in the cave itself. A distinct aspect of the IUP occupation is an increase in carnivore remains with human modifications, including these cave bears but also smaller taxa (e.g., Canis lupus, Vulpes vulpes). This can be correlated with their exploitation for pendants, and potentially for skins and furs. At a broader scale, we identified similarities in subsistence behavior across IUP sites in Europe and western Asia. It appears that the first IUP occupations were less intense with find densities and human modifications increasing in succeeding IUP layers. Moreover, the exploitation of small game appears to be limited across IUP sites, while carnivore exploitation seems a recurrent strategy.