William Gearty
University of Nebraska-Lincoln, United States
August 30, 2022
Body Mass Constraints on Aquatic Invasions in Tetrapods
Re-invasion of the aquatic realm has occurred across the tetrapod tree over the past 300 million years, but secondarily aquatic tetrapod lineages have not diversified to the same extent upon reinvasion of the water nor have they lasted for nearly as long. Such invasions are relatively uncommon and unsuccessful most likely due to the differences in the physical and chemical conditions on land versus in water. Comparative phylogenetic methods reveal that modern and fossil marine representatives of both Mammalia and Crocodyliformes have evolved to significantly larger sizes than their terrestrial counterparts to overcome these challenges. In addition to this change in size, they also maintain smaller degrees of evolutionary variation and significantly faster rates of evolution. Physiological models that combine constraints from thermoregulation, metabolism, lung capacity, and/or feeding indicate that the regulation of body heat plays a major role in determining minimum viable sizes for mammals and crocodyliforms, while metabolism and feeding capacity may limit maximum viable sizes.
Heather Page
Sea Education Association, United States
August 23, 2022
See the Sea: Inclusion and Accessibility for At-Sea Education and Research Experiences
Increasing diversity in the geosciences requires building accessible, inclusive environments where everyone feels a sense of belonging. Experiential learning can have positive, transformative impacts on young people’s sense of belonging within STEM fields. Therefore, how can support inclusion and accessibility for at-sea education and research experiences? This talk explores this question through personal experiences as a deaf scientist and educator at Sea Education Association (SEA).
Jazmin Scarlett
University of East Anglia, United Kingdom
August 16, 2022
Volcanoes in popular videogames: (in)accuracies and pedagogy
Volcanoes are a very common staple in mainstream video games. Particularly within the
action/adventure genres, entire missions or even full storylines can require players to transverse an active volcano. With modern advancements in video game capabilities and graphics, many of these volcanic regions contain a lot of detail. Most video games nowadays have gameplay times in excess of 50 hours. Therefore, players can spend a substantial amount of time immersed within the detailed graphics, and unknowingly learn about volcanic traits while playing. If these details are factually accurate to what we observe in real world volcanic systems, then video games can prove to
be a powerful learning tool. However, inaccurate representations could instil a false understanding in thousands of players worldwide.
Sean Thatcher
CUNY, College of Staten Island, United States
August 9, 2022
A Field Course for Everyone: The Benefits of Accommodation and Inclusion in Field Experiences
Field experiences are a common degree requirement in many geoscience programs and are not always accessible to students with disabilities or for other underrepresented groups. Because of this many students may fail to see themselves in this field, potentially switching majors or leaving the geosciences entirely. This talk discusses the importance of accessible and inclusive field experiences, their design, and implementation through the NSF funded GeoSPACE Program (NSF Award #2023124). Here we will share how sites were selected, our hybrid model combining in-person and virtual student participation, collaboration between these groups, and lessons learned for next year’s field trip.
Matteo Fabbri
Field Museum of Natural History, United States
August 2, 2022
Diving behavior among dinosaurs
Based on anatomical features, dinosaurs have been considered ecologically restricted to terrestrial environments for centuries. The discovery of a new skeleton of Spinosaurus has challenged this paradigm: the presence of a crocodile-mimic snout, shortened hindlimbs, and a fin-like tail have been suggested to be adaptations to swimming behaviors in fresh water ecosystems. However, this hypothesis remains controversial. In one of my recent studies, I used bone density as a proxy for inferring ecological adaptations in extinct species. Based on the largest dataset ever assembled for this proxy, I was able to demonstrate that spinosaurids, a group of carnivorous giant predators, were capable of diving underwater.
Anjana Khatwa
Wessex Museums, UK
July 26, 2022
Black and Brown Faces in Green Spaces
For over 20 years I have been an anomaly. One of the very few BAME faces in working in the heritage and conservation sector. But why does this matter? Without diverse and equitable representation, we cannot hope to deliver an effective service within the natural heritage sector that speaks for all of our society. So how can we as scientists and champions of nature affect a change that could literally transform the face of the sector? Through championing role models, decolonising the curriculum and challenging the stereotypes and fear that exists in a space that isolates the ethnic minority community, together we can catalyse change.
Michael Kipp
CalTech, USA
July 19, 2022
The evolution of nitrogen-fixing symbiosis in cycads: An isotopic perspective
Cycads are an ancient group of gymnosperms (flowerless, seed-producing plants). Sometimes called “living fossils”, they were abundant and diverse in the Mesozoic but subsequently became scarce and ecologically restricted. Phylogenetic studies have inferred a recent origin of all extant cycad species, potentially hinting at widespread extinction in the clade between the late Mesozoic and present day. However, it remains unclear what process(es) might have driven that extinction. Here we sought to illuminate that issue by probing the antiquity of a hallmark of cycad physiology: symbiotic nitrogen fixation. All extant cycad species harbor symbiotic nitrogen-fixing cyanobacteria in their roots. We developed a novel nitrogen isotope approach to track symbiotic nitrogen fixation in fossil cycads. Our analyses reveal that despite its universal occurrence across extant cycads, nitrogen-fixing symbiosis is not ancestral, but rather arose independently in the lineages leading to modern cycads. This strongly points to a role of competition for essential nutrients in the evolutionary history of cycads (and perhaps other gymnosperms) from the Mesozoic to present.
Ian Castro
University of Cincinnati, USA
July 12, 2022
Disability Critical Race Theory (DisCrit) in Geoscience Field Research: A Call to Action for
new frameworks to Assess Accessibility and Inclusion for Field Settings
While field experiences can be valuable for prospective research practitioners, this is not always the case for those with identities commonly underrepresented in the geoscience disciplines. Assessing new methods for approaching field experiences is essential to gain a better understanding of how the needs of all geoscience field researchers can be supported. In this call to action, disability critical race theory (DisCrit) is proposed as a framework to explore the intersections of race and ability in the geosciences, and in particular for field experiences. Through an intersectional lens, opportunities to broaden participation and to develop a more accessible and inclusive field discipline can be developed to further expand geoscience field research.
Melissa Kemp
University of Texas at Austin, USA
July 5, 2022
Extinction, Colonization, and Conservation in a biodiversity hotspot: Lessons from the Caribbean fossil record
The Caribbean is one of the most well-studied biodiversity hotspots, regions that in total cover less than 3% of the Earth’s surface yet host the majority of the planet’s endemic species. But the diversity of today’s Caribbean is only a fraction of what once existed there, as climate, sea-level fluctuations, and multiple human colonization events have restricted the ranges of many species, or worse, contributed to
their extinction. Given this past history of environmental perturbations, paleobiology is
well-suited to inform ongoing conservation needs in this system. Such perspective from
the past is essential now more than ever before, as continued habitat degradation, non-
native species introductions, and ongoing range contraction, extirpation, and extinction
threaten to erode the remaining biodiversity. My research explores how one seemingly successful group of Caribbean vertebrates, the lizards, have been impacted by environmental perturbations throughout the Pleistocene, Holocene, and into the
Anthropocene. By utilizing historic museum specimens and fossils from paleontological
sites, as well as the entire breadth of modern Caribbean lizard diversity, I unveil extinction biases and colonization patterns within the Caribbean, and the ramifications of these dynamics on community structure and resilience. These observations have transformed how we understand lizard extinctions globally and have the potential to
shape conservation policy for this dynamic group of vertebrates.
Tianchen He
University of Leeds, UK
June 28, 2022
Marine redox dynamics across the end-Triassic mass extinction
The role of ocean deoxygenation as a cause of the end–Triassic marine mass extinction is widely debated. Here I present multi-proxy geochemical data to reconstruct the full water-column redox landscape across the shallow to deep-water marine realms of the western Tethys and eastern Panthalassa during the Triassic–Jurassic transition. Results show local dissolved oxygen decline in the near-surface ocean of low-latitude Tethys across the extinction, synchronous with the spread of deeper anoxic waters on the wider continental shelves and slopes. Further, more persistently euxinic conditions prevailed across the Triassic–Jurassic boundary in many semi-enclosed basins of the NW European epicontinental sea, coinciding precisely with the major phase of benthic faunal loss at the regional scale. Hence, the coincidence of extreme redox shifts with the extinction losses on a global scale implicates oxygen scarcity as an important factor in the crisis.
Sofía Barragán Montilla
MARUM, Germany
June 23, 2022
Climate change in the North Atlantic deep ocean: lessons from the recent past
Using benthic foraminifera, this research aims to understand how deep bottom water temperatures responded to the slowdown of the Atlantic Meridional Overturning Circulation during the last deglaciation. Our geochemical multi-proxy dataset, suggests that changes in heat uptake due to significant modifications of North Atlantic circulation (similar to those predicted for the 21st century) have the potential to enhance global warming in the future.
David Evans
Goethe-Universität Frankfurt am Main, Germany
June 14, 2022
The changing major ion chemistry of seawater is an important driver of long-term CO2
The cause of the observed ~1000 ppm decrease in the atmospheric concentration of CO2 through the Cenozoic remains elusive. Here, we couple a near-continuous record of the precise degree of seawater major ion chemistry change over this interval with a carbon cycle model in order to explore whether the changing chemistry of seawater is a previously underappreciated factor controlling CO2, and thus climate. Based on these results, we argue that the concentration of calcium in seawater is in itself a likely driver of the long-term carbon cycle and that the observed Cenozoic change can directly account for the bulk of the coincident CO2 decrease.
Jack Shaw
Sante Fe Institute
June 7, 2022
Exploring fundamental differences between the structures of Cambrian and modern communities
The Earth system has changed dramatically since animals first evolved, including the development of new biotic niches and the widespread oxygenation of oceans. Recently it has been hypothesized that the evolution of this system may have been driven by the relative longevity of communities with net-positive ecosystem effects. Compelling though this idea is, evidence for it in fossil data is lacking. In this talk I will show how analyses of ancient and modern food webs can elucidate the structure, function, and dynamics of communities through deep time to look for trends in such ecosystem effects. Comparisons of Cambrian and modern food webs reveal previously hypothesized changes in trophic structure across the history of animal life, including increased predation, ecological differentiation and, perhaps, greater stability. Taken in concert with our rapidly advancing understanding of environmental conditions across the Phanerozoic, this approach could be used to identify the mechanisms underlying ecological change and the regulation of the biosphere.
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