-
Reconstructing the nonadaptive radiation of an ancient lineage of ground-dwelling stick insects (Phasmatodea: Heteropterygidae)
-
Located in
Library
/
RBINS Staff Publications 2021
-
A new species of the genus Psalidosphryon Komiya, 2001 from West Papua, Indonesia (Coleoptera, Cerambycidae, Prioninae)
-
Located in
Library
/
RBINS Staff Publications 2021
-
Four new West Palaearctic species and new distributional records of Hybotidae (Diptera)
-
Located in
Library
/
RBINS Staff Publications 2021
-
Annelids in Extreme Aquatic Environments: Diversity, Adaptations and Evolution
-
Located in
Library
/
RBINS Staff Publications 2021
-
Cryptophyllium, the hidden leaf insects – descriptions of a new leaf insect genus and thirteen species from the former celebicum species group (Phasmatodea, Phylliidae)
-
Located in
Library
/
RBINS Staff Publications 2021
-
Bistability in the redox chemistry of sediments and oceans
-
For most of Earth’s history, the ocean’s interior was pervasively anoxic and showed occasional shifts in ocean redox chemistry between iron-buffered and sulfide-buffered states. These redox transitions are most often explained by large changes in external inputs, such as a strongly altered delivery of iron and sulfate to the ocean, or major shifts in marine productivity. Here, we propose that redox shifts can also arise from small perturbations that are amplified by nonlinear positive feedbacks within the internal iron and sulfur cycling of the ocean. Combining observational evidence with biogeochemical modeling, we show that both sedimentary and aquatic systems display intrinsic iron–sulfur bistability, which is tightly linked to the formation of reduced iron–sulfide minerals. The possibility of tipping points in the redox state of sediments and oceans, which allow large and nonreversible geochemical shifts to arise from relatively small changes in organic carbon input, has important implications for the interpretation of the geological rock record and the causes and consequences of major evolutionary transitions in the history of Earth’s biosphere
Located in
Library
/
RBINS Staff Publications 2020
-
Advancing the Catalogue of the World’s Natural History Collections
-
Information about natural history collections helps to map the complex landscape of research resources and assists researchers in locating and contacting the holders of specimens. Collection records contribute to the development of a fully interlinked biodiversity knowledge graph (Page 2016), showcasing the existence and importance of museums and herbaria and supplying context to available data on specimens. These records also potentially open new avenues for fresh use of these collections and for accelerating their full availability online.A number of international (e.g., Index Herbariorum, GRSciColl) regional (e.g. DiSSCo and CETAF) national (e.g., ALA and the Living Atlases, iDigBio US Collections Catalog) and institutional networks (e.g., The Field Museum) separately document subsets of the world's collections, and the Biodiversity Information Standards (TDWG) Collection Descriptions Interest Group is actively developing standards to support information sharing on collections. However, these efforts do not yet combine to deliver a comprehensive and connected view of all collections globally.The Global Biodiversity Information Facility (GBIF) received funding as part of the European Commission-funded SYNTHESYS+ 7 project to explore development of a roadmap towards delivering such a view, in part as a contribution towards the establishment of DiSSCo services within a global ecosystem of collection catalogues. Between 17 and 29 April 2020, a coordination team comprising international representatives from multiple networks ran Advancing the Catalogue of the World’s Natural History Collections, a fully online consultation using the GBIF Discourse forum platform to guide discussion around 26 consultation topics identified in an initial Ideas Paper (Hobern et al. 2020). Discussions included support for contributions in Spanish, Chinese and French and were summarised daily throughout the consultation.The consultation confirmed broad agreement around the needs and goals for a comprehensive catalogue of the world’s natural history collections, along with possible strategies to overcome the challenges. This presentation will summarise the results and recommendations.
Located in
Library
/
RBINS Staff Publications 2020
-
Bistability in the redox chemistry of sediments and oceans
-
For most of Earth’s history, the ocean’s interior was pervasively anoxic and showed occasional shifts in ocean redox chemistry between iron-buffered and sulfide-buffered states. These redox transitions are most often explained by large changes in external inputs, such as a strongly altered delivery of iron and sulfate to the ocean, or major shifts in marine productivity. Here, we propose that redox shifts can also arise from small perturbations that are amplified by nonlinear positive feedbacks within the internal iron and sulfur cycling of the ocean. Combining observational evidence with biogeochemical modeling, we show that both sedimentary and aquatic systems display intrinsic iron–sulfur bistability, which is tightly linked to the formation of reduced iron–sulfide minerals. The possibility of tipping points in the redox state of sediments and oceans, which allow large and nonreversible geochemical shifts to arise from relatively small changes in organic carbon input, has important implications for the interpretation of the geological rock record and the causes and consequences of major evolutionary transitions in the history of Earth’s biosphere.
Located in
Library
/
No RBINS Staff publications
-
Quantification of Cable Bacteria in Marine Sediments via qPCR
-
Cable bacteria (Deltaproteobacteria, Desulfobulbaceae) are long filamentous sulfur-oxidizing bacteria that generate long-distance electric currents running through the bacterial filaments. This way, they couple the oxidation of sulfide in deeper sediment layers to the reduction of oxygen or nitrate near the sediment-water interface. Cable bacteria are found in a wide range of aquatic sediments, but an accurate procedure to assess their abundance is lacking. We developed a qPCR approach that quantifies cable bacteria in relation to other bacteria within the family Desulfobulbaceae. Primer sets targeting cable bacteria, Desulfobulbaceae and the total bacterial community were applied in qPCR with DNA extracted from marine sediment incubations. Amplicon sequencing of the 16S rRNA gene V4 region confirmed that cable bacteria were accurately enumerated by qPCR, and suggested novel diversity of cable bacteria. The conjoint quantification of current densities and cell densities revealed that individual filaments carry a mean current of ~110 pA and have a cell specific oxygen consumption rate of 69 fmol O2 cell-1 day-1. Overall, the qPCR method enables a better quantitative assessment of cable bacteria abundance, providing new metabolic insights at filament and cell level, and improving our understanding of the microbial ecology of electrogenic sediments.
Located in
Library
/
No RBINS Staff publications
-
Burrowing fauna mediate alternative stable states in the redox cycling of salt marsh sediments
-
The East Anglian salt marsh system (UK) has recently generated intriguing data with respect to sediment biogeochemistry. Neighbouring ponds in these salt marshes show two distinct regimes of redox cycling: the sediments are either iron-rich and bioturbated, or they are sulphide-rich and unbioturbated. No conclusive explanation has yet been given for this remarkable spatial co-occurrence. Here, we quantify the geochemical cycling in both pond types, using pore-water analyses and solid-phase speciation. Our results demonstrate that differences in solid-phase carbon and iron inputs are likely small between pond types, and so these cannot act as the direct driver of the observed redox dichotomy. Instead, our results suggest that the presence of bioturbation plays a key role in the transition from sulphur-dominated to iron-dominated sediments. The presence of burrowing fauna in marine sediments stimulates the mineralisation of organic matter, increases the iron cycling and limits the build-up of free sulphide. Overall, we propose that the observed dichotomy in pond geochemistry is due to alternative stable states, which result from non-linear interactions in the sedimentary iron and sulphur cycles that are amplified by bioturbation. This way, small differences in solid phase input can result in very different regimes of redox cycling due to positive feedbacks. This non-linearity in the iron and sulphur cycling could be an inherent feature of marine sediments, and hence, alternative stable states could be present in other systems.
Located in
Library
/
No RBINS Staff publications