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Temperature-Related Stresses as a Unifying Principle in Ancient Extinctions

Combined with local and regional anthropogenic factors, current human-induced climate warming is thought to be a major threat to biodiversity. The ecological imprint of climate change is already visible on land and in the oceans. The imprint is largely manifested in demographic/abundance changes and phenological and distribution shifts, whereas only local extinctions are yet attributable to climate change with some confidence. This is expected to change in the near future owing to direct heat stress, shortage of food, mismatches in the timing of seasonal activities, geographic barriers to migration, and new biological interactions. Additional stressors are associated with climate warming in marine systems, namely acidification and deoxygenation. Ocean acidification is caused by the ocean’s absorption of CO2 and deoxygenation is a result of warmer water, increased ocean stratification and upwelling of hypoxic waters. The combination of warming, acidification and deoxygenation is known as the “deadly trio”. Temperature is the most pervasive environmental factor shaping the functional characteristics and limits to life and is also central to the generation and biological effects of hypoxic waters and to modulating the effects of ocean acidification, with and without concomitant hypoxia. Due to the key role of temperature in the interaction of the three drivers we termed these temperature-related stressors (TRS).

  • Deep origins of marine trophic networks
    (FAU Funds)
    Term: 1. January 2017 - 28. February 2018
  • Constraining the deep origin of metazoan parasitism through integration of Evolutionary Parasitology and Molecular Paleobiology
    (FAU Funds)
    Term: 1. January 2017 - 31. December 2017
  • Environmental and biotic controls on conodont body size and teeth morphology as proxies for their feeding ecology
    (Third Party Funds Single)
    Term: 1. September 2016 - 31. August 2019
    Funding source: DFG-Einzelförderung / Sachbeihilfe (EIN-SBH)
    Before the advent of jawed vertebrates, conodonts were the most abundant and diverse predators of early Palaeozoic oceans. Their phosphatic teeth abound in upper Cambrian through Triassic marine rocks. Thanks to their extraordinarily rapid morphological evolution, conodonts are established as a prime tool in biostratigraphy. Yet the feeding ecology that allowed this rapid diversification of food-processing structures remains unknown.The core question of this project is: How does conodont morphology reflect their trophic position, diet, and environmental conditions? This project will develop quantitative proxies to study conodont teeth and provide models of their variability in function of the abiotic environment (lithofacies) and biotic interactions (community structure). Teeth size will be quantified as a proxy for prey size, and thickness of the biomineralized tissue will be used as an indicator of durophagy. These parameters will be examined across well-documented environmental gradients in the middle Silurian carbonate succession of Gotland, Sweden. The project will allow distinguishing ecophenotypic variability from microevolutionary patterns. It will also identify the key controls on this variability by testing ecological models derived from other faunal groups, e.g. the relationship between body size structure in a community and the length of the trophic chain. These models will be independently tested by applying geochemical proxies for the trophic level of individual organisms. The project will provide a framework within which conodont morphological diversity across geological successions can be interpreted by partitioning it into ecophenotypic and evolutionary trends.
  • Body size dynamics of cephalopods across the Pliensbachian-Toarcian crisis
    (Third Party Funds Group – Sub project)
    Overall project: Temperature-related stresses as a unifying principle in ancient extinctions (TERSANE)
    Term: 1. August 2016 - 31. July 2019
    Funding source: DFG / Forschergruppe (FOR)
    The reduction of body size within individual lineages is suggested to be one of the most important responses in the face of temperature-related stressors. Despite common suggestions of similar size changes around mass extinction events, the global significance as well as the mechanisms of this Lilliput effect are still controversial. This project aims at understanding the role of warming and associated stressors (anoxia) in driving body size changes of marine organisms in the Early Jurassic (Toarcian) crisis. We focus on cephalopods along a N/S-gradient of western Europe and northwestern Africa to explore patterns of body sizes from individual taxa to entire assemblages. Patterns will be explicitly analysed in the context of sedimentary facies, physico-chemical proxies and physiological predictions to test the correlation of body size with environmental parameters such as temperature, oxygenation and productivity/burial of organic carbon.
  • Biotic consequences of temperature-related stresses across temporal scales
    (Third Party Funds Group – Sub project)
    Overall project: Temperature-related stresses as a unifying principle in ancient extinctions (TERSANE)
    Term: 1. January 2016 - 1. January 2019
    Funding source: DFG / Forschergruppe (FOR)
    Understanding the physiological constraints of extant species is of critical importance to interpret ancient responses to temperature-related stresses (TRS). Likewise, anticipating the biotic responses to current climate change will benefit from an analysis of biotic responses observed in the geological past. Embedded in the Research Unit TERSANE we propose a project, which explicitly combines neontological and paleontological approaches to assess the consequences of warming, ocean acidification, and various degrees of hypoxia for marine life. The project focuses on the compilation and analysis of large datasets and has three main components: (1) A meta-analysis of (a) extant organisms will summarize experimental and observational data on responses and critical limits of marine organisms to quantify the sensitivities of higher, fossilizable taxa to warming, ocean acidification, and hypoxia and their synergies, and (b) a meta-analysis of fossil observations will focus on assessing the veracity of the Lilliput effect, the reduction of body sizes in the aftermath of mass extinctions, which is sometimes thought to be related to TRS. (2) The analysis of primary occurrence data from the fossil record will evaluate the physiological and biogeographic selectivity of the end-Permian and Early Jurassic extinction events to test if the physiological principles derived from modern observations scale up to selective extinction risk in the face of extreme climate change. (3) The assessment of ancient rates of climate and environmental changes from local sections is critical to test if these rates were genuinely lower than over the last 50 years, or if the apparently lower rates observed in the past are just statistical artifacts due to the different time scales. A scaling-adjusted rate estimate will help making our findings relevant for modern climate change ecology. These three components will finally be integrated to evaluate the commonality of patterns and eco-physiological selectivity of extinctions as visible in paleo- and extant data.
  • Charakterisierung, Langzeitverhalten und Engineering des Reservoirs zur Minimierung des Fündigkeitsrisikos
    (Third Party Funds Group – Sub project)
    Overall project: Geothermie-Allianz Bayern (GAB)
    Term: 1. January 2016 - 31. December 2019
    Funding source: Bayerisches Staatsministerium für Bildung und Kultus, Wissenschaft und Kunst (ab 10/2013)
    Das bayerische Molassebecken ist bislang das einzige Vorlandbecken weltweit aus dem erfolgreich geothermisch Strom und Wärme produziert wird. Die Machbarkeit der geothermischen Energiegewinnung aus niederen Temperaturen von etwa 150°C ist damit bewiesen und die Geothermie hat damit das Potenzial, einen wesentlichen Anteil des Energiebedarfs in Bayern regenerativ abzudecken.
    Die Erfahrungen aus den bisherigen installierten oder in der Entwicklung befindlichen Geothermiefeldern zeigen aber auch, dass wesentliche Fragen in der geothermischen Technologienentwicklung bislang nicht geklärt werden konnten. So sind für die Planung und Durchführung von Geothermie-Projekte hohe Investitionen notwendig, die insbesondere am Beginn des Projekts durch die Niederbringung der Bohrungen erforderlich sind. Ob und in welchem Maße ein Geothermie-Projekt wirtschaftlich erfolgreich ist hängt unmittelbar mit Risiken bei der geologischen Erschließung und deren Fündigkeit zusammen. So entstanden
    in der Vergangenheit durch nicht erfolgreiche Bohrungen bzw. dem Verfehlen von wirtschaftlich
    gesetzten Zielen bei Geothermie-Projekten Unsicherheiten für Investoren, Versicherer
    und Betreiber. Eine optimierte Explorationsstrategie und ein verbessertes Verständnis der hydrogeologischen und thermischen Ausprägung des Reservoirs sollen das Bohr- und Fündigkeitsrisiken senken, die Planungssicherheit erhöhen und damit die Attraktivität der Geothermie für Investoren steigern. Die Kenntnis des langfristigen dynamischen Verhaltens des Reservoirs bezüglich der nutzbaren Volumenströme und thermischen Entwicklung bietet zudem eine höhere Sicherheit für die Planung der Wirtschaftlichkeit geothermischer Anlagen und Optimierungsmöglichkeiten ihrer Betriebsweise.

    Eine systematische wissenschaftliche Begleitung von Geothermieprojekten und die daraus zu gewinnenden Rückschlüsse auf das Reservoir und deren Fündigkeit bis hin zu einem Testfeld für
    geothermische Technologienentwicklung, die von der Erkundung und Bohrung bis zur Reservoir-
    Evaluierung und dem Reservoir-Engineering reicht, fehlen bislang. Das vorliegende Forschungsprojekt soll diese relevanten Fragestellungen aufgreifen und beantworten.Die übergeordneten Ziele des vorliegenden Projektes sind das Risiko für eine geothermische Fündigkeit im süddeutschen Molassebecken zu reduzieren und Unsicherheiten des Reservoir-Engineering und des geothermischen Langzeitbetriebs einzuschränken und somit den Betrieb zu optimieren.

  • FOR 2332: Temperature-related stresses as a unifying principle in ancient extinctions (TERSANE)
    (Third Party Funds Group – Overall project)
    Term: 1. January 2016 - 1. January 2019
    Funding source: DFG / Forschergruppe (FOR)
    Anthropogenic global warming is regarded as a major threat to species and ecosystems worldwide. Predicting the biological impacts of future warming is thus of critical importance. The geological record provides several examples of mass extinctions and global ecosystem pertubations in which temperature-related stresses are thought to have played a substantial role. These catastrophic natural events are potential analogues for the consequences of anthropogenic warming but the Earth system processes during these times are still unexplored, especially in terms of their ultimate trigger and the extinction mechanisms. The Research Unit TERSANE aims at assessing the relative importance of warming-related stresses in ancient mass extinctions and at evaluating how these stresses emerged under non-anthropogenic conditions. An interdisciplinary set of projects will combine high-resolution geological field studies with meta-analyses and sophisticated analysis of fossil occurrence data on ancient (suspect) hyperthermal events to reveal the rate and magnitude of warming, their potential causes, their impact on marine life, and the mechanisms which led to ecologic change and extinction. Geochemistry, analytical paleobiology and physiology comprise our main toolkit, supplemented by biostratigraphy, sedimentology, and modelling.
  • Exploring biodiversity evolution in tropical seas based on comparisons of the Triassic fauna of the Cassian Formation with modern faunas
    (Third Party Funds Single)
    Term: 1. May 2015 - 1. May 2018
    Funding source: DFG-Einzelförderung / Sachbeihilfe (EIN-SBH)
    The Triassic Cassian Formation yields an exceptionally diverse marine tropical invertebrate fauna offering a largely unbiased assessment of the complexity and biodiversity of early Mesozoic ecosystems. The fauna consist of various assemblages from different localities and paleoenvironments, which vary strongly in terms of diversity and composition. Fossil preservation is usually exceptional including primary aragonite and a rich fauna of small species. Based on standardized large-scale bulk-sampling, we want to assess the true within and between community biodiversity, ecological complexity, taxonomic structure, and size distribution of Triassic tropical shallow water assemblages. Comparisons with assemblages of Recent and Quaternary tropical settings will be used to assess biological changes in diversity and complexity over more than 200 million years of evolution. By comparison with modern samples and existing datasets representing diagenetically more strongly altered (`normal´) fossil assemblages, the effect of taphonomy on preserved diversity, size distribution and ecological structure can be tested. Many of the groups, which are highly diverse in recent tropical faunas (e.g., heterodont bivalves and neogastropods) radiated not before the Cretaceous. We aim at testing if similarly diverse and ecologically dominant clades were present in the Triassic or if diversity was more evenly spread among higher taxa.
  • Biogeographic and community response of reef corals to Pleistocene interglacial warming
    (Third Party Funds Single)
    Term: 1. September 2014 - 1. September 2017
    Funding source: DFG-Einzelförderung / Sachbeihilfe (EIN-SBH)
  • Paleobiodiversity and community structures of Lagerstätten during the Late Paleozoic Ice Age and the response of the marine benthic invertebrate fauna to global cooling
    (Third Party Funds Single)
    Term: 1. July 2014 - 1. July 2017
    Funding source: DFG-Einzelförderung / Sachbeihilfe (EIN-SBH)
    Paleo-biodiversity studies have become of increasing interest and numerous manuscripts have been published dealing with global diversity trends throughout the Phanerozoic. However, data used in these studies mostly derive from databases that may contain various biases and therefore distort statistical analysis. Moreover, Fossil Lagerstätten are commonly excluded although the quality of preservation and information is much better than in other deposits - fossil assemblages from Lagerstätten reflect the composition of former living communities to a much higher degree.The Phanerozoic is marked by two long-term cooling events. One of these is the Late Paleozoic Ice Age (LPIA) with its major onset in the middle to late Mississippian (Lower Carboniferous) and ending in the mid-Sakmarian (Permian). This project focuses on the paleo-biodiversity during the Upper Carboniferous (Pennsylvanian), i.e. during a large part of the LPIA. Instead of purely using information from databases three fossil Lagerstätten (here Lagerstätten is used in terms of exceptionally preserved fauna; e.g. original shell material, color patterns, delicate ornamentation, minute larval shells) are sampled. These localities were influenced by the glacio-eustatic regime during the LPIA and are, from the American Midcontinent, the Finis Shale (Virgilian) and the Buckhorn Asphalt Quarry (Desmoinesian) and, from the Appalachian Basin, the Kendrick Shale (Morrowan).One objective of this project is to study true biodiversities and ecological structures within deposits of exceptionally preserved fossils based on the fact that such deposits depict a more complete image of the original fossil assemblage than other localities. Stanley & Powell (2003) found that during the Pennsylvanian the rates of origination and extinction were depressed and that the global biodiversity remained relatively stable, whereas Alroy et al. (2008) found a general decrease in this period. Therefore, as the second objective, it will be tested if these previous results are visible in Lagerstätten from the Pennsylvanian as well: Do we also see depressed origination and extinction rates or decreasing biodiversity or are the results presented by Stanley & Powell (2003) and Alroy et al. (2008) caused by biases in their data, as for example by faunas of less quality of preservation? Furthermore, diversity dynamics will be studied by analyzing the Carboniferous-Permian faunal turnover. Which taxa control the diversities? The local marine paleo-temperatures within each profile will be investigated. Isotope-analyses will be carried out for the Finis Shale, the Buckhorn Asphalt Quarry, and the Kendrick Shale. Temperature and diversity will be cross correlated to shed light on the relation of temperature and biodiversity during the LPIA to answer the question 'How does the living environment react to global cooling?'.
  • Controls on global biodiversity patterns and skeletal mineralizsation during the Cambrian radiation
    (Third Party Funds Group – Sub project)
    Overall project: FOR 736: The Precambrian-Cambrian Biosphere Revolution: Insights from Chinese Microcontinents
    Term: 1. March 2011 - 31. October 2014
    Funding source: DFG / Forschergruppe (FOR)
    Dieses Projekt zielt darauf ab, die globale Diversitätsdynamik um die Ediacarium-Kambrium- Grenze zuverlässig zu dokumentieren und die Daten für rigoroses Testen von Hypothesen zu verwenden. Eigene Geländestudien in Kasachstan und Südchina werden durch Daten aus der Forschergruppe und publizierte Daten in der Paleobiology Database ergänzt, um einen möglichst repräsentativen Datensatz zu erhalten. Muster der Alpha-, Beta- und Gamma- Diversität werden untersucht, um die relative Rolle von Diversitätsänderungen innerhalb und zwischen Fossilgemeinschaften sowie die Bedeutung biogeographischer Muster zu verstehen. Diese Muster werden verwendet, um Hypothesen zur Ursache der kambrischen Radiation zu testen. Besonders der mögliche Zusammenhang zwischen evolutionärer Innovation auf der einen Seite und Lebensräumen auf der anderen Seite wird in dieser Hinsicht neue Erkenntnisse zur Rolle von Sauerstoff, Nährstoffen und Klimaveränderungen in der kambrischen Radiation liefern. Die Geländearbeit wird sich auf Riffstrukturen im untersten Kambrium und Makroinvertebraten konzentrieren, um Muster der Biomineralisation zu erfassen.
  • Evolutionary rates of zooxanthellate and azooxanthellate corals and their controlling factors
    (Third Party Funds Single)
    Term: 1. February 2011 - 1. February 2014
    Funding source: DFG-Einzelförderung / Sachbeihilfe (EIN-SBH)
    Our goal is to identify the underlying causes of evolutionary rates within scleractinian corals. Scleractinians have two fundamentally different ecologies: Those that retrieve a substantial proportion of their nutrition from symbiotic algae in their tissue (zooxanthellate corals) and those that entirely depend on zooplankton for feeding Proposal Kiessling 2 (azooxanthellate corals). We will be analyzing the evolutionary consequences of these different ecological modes and correlated traits such as coloniality and environmental affinity. While photosymbiosis is clearly beneficial at the organismic level, there is a trade-off in terms of evolutionary benefit because zooxanthellate reef corals seem to be more sensitive to environmental change and tended to be affected more strongly by extinction events than other corals. Evolutionary rates are measured by a novel combination of samplingstandardized biodiversity dynamics and molecular methods. The changes in diversification, speciation, and extinction patterns will be compared with global changes in the marine environment and evolutionary changes in ecology to learn more about the circumstances favoring the spread and demise of these different corals. Thereby, we expect to improve estimates of extinction risk of modern corals.