Project description:A dentine sample from a previously unknown hominin specimen deriving from the Tibetan Plateau was analyzed using LC-MS/MS in order to characterize its proteome, protein damage characteristics, and phylogenetic affinities to known Late Pleistocene hominin clades (humans, Neanderthals, Denisovans).
Project description:Characterization of Middle Pleistocene rhinoceros proteins and the phylogenetic relationships between extinct and extanct rhinoceros was investigated by obtaining ancient protein data for two extinct rhinoceros genera (Coelodonta antiquitatis and Stephanorhinus sp.).
Project description:Genetic and limited palaeoanthropological data suggest that Denisovans, a sister group to Neanderthals, were once widely distributed in eastern Eurasia, likely stretching from high-latitude Siberia, to the high-altitude Tibetan Plateau, to the low-latitude subtropical regions of southeast Asia. This suggests that Denisovans were capable of adapting to a highly diverse range of environments, but archaeological evidence for this is currently limited. As a result, we know little about their behaviours, including subsistence strategies, across the vast areas they likely occupied. Here, we describe the late Middle to Late Pleistocene faunal assemblage from Baishiya Karst Cave on the Tibetan Plateau, where the Xiahe Denisovan mandible and Denisovan sedimentary mtDNA were found, by integrating proteomic screening into traditional zooarchaeological analysis. The results indicate that the faunal assemblage consists of a diverse range of animals, including megafauna, large mammals, small mammals and birds, but is dominated by medium-sized herbivores. Frequent cut marks and percussion traces on bone surfaces throughout the assemblage, even on carnivore bones, indicate that Denisovan activities in Baishiya Karst Cave from at least 190 to 30 thousand years are responsible for the fauna assemblage accumulation. Thorough utilization of acquired animal resources, even perhaps the fur, too, might have helped Denisovans to survive through the last two glacial-interglacial cycles on the cold high-altitude Tibetan Plateau. Our results shed new light on Denisovan behaviours and their adaptations to the diverse and fluctuated environments in the Middle and Late Pleistocene eastern Eurasia.
Project description:Ultraslow spreading ridges account for one-third of the global mid-ocean ridges. Their impact on the diversity and connectivity of benthic deep-sea microbial assemblages is poorly understood, especially for hydrothermally inactive, magma-starved ridges. We investigated bacterial and archaeal diversity in sediments collected from an amagmatic segment (10°-17°E) of the Southwest Indian Ridge (SWIR) and in the adjacent northern and southern abyssal zones of similar water depths within one biogeochemical province of the Indian Ocean. Microbial diversity was determined by 16S ribosomal RNA (rRNA) gene sequencing. Our results show significant differences in microbial communities between stations outside and inside the SWIR, which were mostly explained by environmental selection. Community similarity correlated significantly with differences in chlorophyll a content and with the presence of upward porewater fluxes carrying reduced compounds (e.g., ammonia and sulfide), suggesting that trophic resource availability is a main driver for changes in microbial community composition. At the stations in the SWIR axial valley (3,655-4,448 m water depth), microbial communities were enriched in bacterial and archaeal taxa common in organic matter-rich subsurface sediments (e.g., SEEP-SRB1, Dehalococcoida, Atribacteria, and Woesearchaeota) and chemosynthetic environments (mainly Helicobacteraceae). The abyssal stations outside the SWIR communities (3,760-4,869 m water depth) were dominated by OM1 clade, JTB255, Planctomycetaceae, and Rhodospirillaceae. We conclude that ultraslow spreading ridges create a unique environmental setting in sedimented segments without distinct hydrothermal activity, and play an important role in shaping microbial communities and promoting diversity, but also in connectivity among deep-sea habitats.