PNAS Science Sessions

Using AI to predict the weather Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scientific community. Learn the behind-the-scenes story of work published in the Proceedings of the National Academy of Sciences (PNAS), plus a broad range of scientific news about discoveries that affect the world around us. In this episode, researchers discuss advances in AI-enabled weather forecasting. In this episode, we cover: •[00:00] Introduction •[01:12] Jeffrey Shrader explains what 48 expert forecasters had to say about how weather predictions might further improve through 2100, including the potential role of AI. •[03:43] Ignacio Lopez-Gomez explains how he used generative AI to downscale large-scale earth system models into finer-scale regional climate projections. •[05:35] Xiaofeng Li explains how he used a machine learning model to forecast whether tropical cyclones will rapidly intensify. •[07:40] Hui Su explains what nowcasting is and how her deep diffusion model works. •[09:52] Pedram Hassanzadeh explains what grey swans are and why they may be challenging for AI to predict. •[10:47] Qiang Sun explains how he and his colleagues tested the ability of AI to predict gray swans. •[12:28] Final thoughts and conclusion. About Our Guests: Jeffrey Shrader Associate Professor of International and Public Affairs Columbia University Ignacio Lopez-Gomez Research Scientist Google Xiaofeng Li Research Scientist Institute of Oceanology, Chinese Academy of Sciences Hui Su Chair Professor Hong Kong University of Science and Technology Pedram Hassanzadeh Associate Professor University of Chicago Qiang Sun Research Scientist University of Chicago View related content here: https://www.pnas.org/doi/full/10.1073/pnas.2523372123 https://www.pnas.org/doi/full/10.1073/pnas.2420288122 https://www.pnas.org/doi/full/10.1073/pnas.2415501122 https://www.pnas.org/doi/full/10.1073/pnas.2517520122 https://www.pnas.org/doi/full/10.1073/pnas.2420914122 Follow us on Spotify, Apple Podcasts, or wherever you get your podcasts for more captivating discussions on scientific breakthroughs! Visit Science Sessions on PNAS.org: https://www.pnas.org/about/science-sessions-podcast Follow PNAS: Twitter/X Facebook LinkedIn YouTube Sign up the PNAS Highlights newsletter

The lost forests of Doggerland Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scientific community. Learn the behind-the-scenes story of work published in the Proceedings of the National Academy of Sciences (PNAS), plus a broad range of scientific news about discoveries that affect the world around us. In this episode, Robin Allaby explores the paleoecology of the submerged area known as Doggerland. In this episode, we cover: •[00:00] Introduction. •[01:10] Evolutionary biologist Robin Allaby introduces the location of Doggerland and history of its exploration. •[02:58] He introduces sedimentary DNA, including how it can be used to reconstruct paleoecology. •[03:43] Allaby describes the methods of the study. •[05:18] He introduces the primary findings about the plant and animal life of Doggerland. •[06:14] He describes the surprising find of Pterocarya in Doggerland. •[08:07] Allaby discusses the habitability of Doggerland for Mesolithic societies. •[09:38] He lists the caveats and limitations of the study. •[10:13] Conclusion. About Our Guest: Robin Allaby Professor University of Warwick View related content here: https://www.pnas.org/doi/full/10.1073/pnas.2508402123 Follow us on Spotify, Apple Podcasts, or wherever you get your podcasts for more captivating discussions on scientific breakthroughs! Visit Science Sessions on PNAS.org: https://www.pnas.org/about/science-sessions-podcast Follow PNAS: Twitter/X Facebook LinkedIn YouTube Sign up for the PNAS Highlights newsletter

A giant virus associated with oyster aquaculture mortality Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scientific community. Learn the behind-the-scenes story of work published in the Proceedings of the National Academy of Sciences (PNAS), plus a broad range of scientific news about discoveries that affect the world around us. In this episode, Curtis Suttle and Kevin Xu Zhong explain how a previously unidentified virus may be connected to mass die-offs of farmed Pacific oysters. In this episode, we cover: • [00:00] Introduction • [01:03] Environmental virologist Curtis Suttle introduces the importance of the Pacific oyster to aquaculture. • [01:42] Suttle describes mass mortality events, including one he witnessed. • [02:42] Environmental microbiologist Kevin Xu Zhong talks about the methods used to identify the Pacific Oyster Nidovirus 1. • [03:53] Zhong describes the notable features of the nidovirus. • [05:19] Zhong and Suttle explain how the nidovirus merits designation of a nidovirus family. • [06:25] Suttle explores the takeaways for oyster farmers and regulators. • [08:15] He lists the caveats and limitations of the study. • [09:40] Conclusion. About Our Guests: Kevin Xu Zhong Research Associate University of British Columbia Curtis Suttle Professor University of British Columbia View related content here: https://www.pnas.org/doi/10.1073/pnas.2426923122 Follow us on Spotify, Apple Podcasts, or wherever you get your podcasts for more captivating discussions on scientific breakthroughs! Visit Science Sessions on PNAS.org: https://www.pnas.org/about/science-sessions-podcast Follow PNAS: Twitter/X Facebook LinkedIn YouTube Sign up for the PNAS Highlights newsletter

Implications of a mutation in modern humans Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scientific community. Learn the behind-the-scenes story of work published in the Proceedings of the National Academy of Sciences (PNAS), plus a broad range of scientific news about discoveries that affect the world around us. In this episode, Xiangchun Ju and Svante Pääbo explore the evolutionary implications of a mutation that separates modern humans from ancestral hominins. In this episode, we cover: •[00:00] •[01:22] Neurobiologist Xiangchun Ju introduces the enzyme adenylosuccinate lyase, or ADSL, and its role in the synthesis of purine. •[02:09] Evolutionary anthropologist Svante Pääbo talks about the discovery of the A429V mutation, which is present in modern humans but not Neanderthals or Denisovans. •[03:38] Ju and Pääbo talk about the methods to humanize mice in order to study the evolutionary importance of the A429V mutation. •[05:04] They explain the results of the behavioral studies of the humanized mice. •[06:27] Pääbo explores the takeaways from the study. •[08:05] He contextualizes the study alongside other studies of modern human development. •[09:17] Pääbo and Ju list the caveats and limitations of the study. •[10:14] Conclusion. About Our Guests: Xiangchun Ju Postdoctoral scholar Okinawa Institute of Science and Technology Svante Pääbo Director Max Planck Institute for Evolutionary Anthropology View related content here: https://www.pnas.org/doi/10.1073/pnas.2508540122 Follow us on Spotify, Apple Podcasts, or wherever you get your podcasts for more captivating discussions on scientific breakthroughs! Visit Science Sessions on PNAS.org: https://www.pnas.org/about/science-sessions-podcast Follow PNAS: Twitter/X Facebook LinkedIn YouTube Sign up for the PNAS Highlights newsletter

Climate change and lake oxygenation Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scientific community. Learn the behind-the-scenes story of work published in the Proceedings of the National Academy of Sciences (PNAS), plus a broad range of scientific news about discoveries that affect the world around us. In this episode, Joachim Jansen explains how climate change altered cycles of oxygenation in lakes. In this episode, we cover: •[00:00] Introduction. •[00:56] Limnologist Joachim Jansen introduces us to the cycles of oxygenation in lakes throughout the seasons. •[02:35] He describes previous hypothesis about climate change and lake oxygenation and introduces the methods and datasets of the study. •[04:59] Jansen introduces the results of the study, including key differences between large and small lakes. •[06:54] He talks about the consequences of deoxygenation. •[09:03] Jansen explains the caveats and limitations of the study. •[09:37] Conclusion. About Our Guest: Joachim Jansen Postdoctoral Researcher University of Helsinki View related content here: https://www.pnas.org/doi/10.1073/pnas.2426140122 Follow us on Spotify, Apple Podcasts, or wherever you get your podcasts for more captivating discussions on scientific breakthroughs! Visit Science Sessions on PNAS.org: https://www.pnas.org/about/science-sessions-podcast Follow PNAS: Twitter/X Facebook LinkedIn YouTube Sign up for the PNAS Highlights newsletter

A pterosaur and its ecosystem at the end of the Triassic Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scientific community. Learn the behind-the-scenes story of work published in the Proceedings of the National Academy of Sciences (PNAS), plus a broad range of scientific news about discoveries that affect the world around us. In this episode, Kay Behrensmeyer and Ben Kligman describe what a fossil bone bed in Arizona reveals about a 209-million-year-old pterosaur and its ecosystem. In this episode, we cover: •[00:00] Introduction •[01:01] Paleoecologist Kay Behrensmeyer and paleontologist Ben Kligman describe the discovery of this fossil bone bed. •[03:10] Kligman and Behrensmeyer introduce a previously undescribed pterosaur. •[05:00] They talk about what this specimen says about the ecology and evolution of pterosaurs. •[06:15] Kligman and Behrensmeyer talk about the importance of studying this fossil community. •[07:52] They explain how their methods can improve paleontology and discovery of small fossils. •[09:08] Behrensmeyer and Kligman talk about the study's caveats and limitations. •[10:10] Conclusion. About Our Guests: Kay Behrensmeyer Curator of Paleobiology National Museum of Natural History, Smithsonian Institution Ben Kligman Postdoctoral Fellow National Museum of Natural History, Smithsonian Institution View related content here: https://www.pnas.org/doi/10.1073/pnas.2505513122 Follow us on Spotify, Apple Podcasts, or wherever you get your podcasts for more captivating discussions on scientific breakthroughs! Visit Science Sessions on PNAS.org: https://www.pnas.org/about/science-sessions-podcast Follow PNAS: Twitter/X Facebook LinkedIn YouTube Sign up for the PNAS Highlights newsletter

Managing eastern black rhinoceros populations with genetic studies Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scientific community. Learn the behind-the-scenes story of work published in the Proceedings of the National Academy of Sciences (PNAS), plus a broad range of scientific news about discoveries that affect the world around us. In this episode, Barbara Mable and Ronald Mellya show how allowing endangered rhinos to move between populations enhances genetic diversity. In this episode, we cover: •[00:00] Introduction •[01:00] Evolutionary geneticist Barbara Mable explains why is genetic diversity important in managing small, isolated populations of rhinos. •[02:59] Park warden Ronald Mellya describes how his firsthand experience with rhino management led to this study. •[04:52] Mable explains the methods of the study and the contributions of co-author Anubhab Khan. •[06:20] Mable talks about the results. •[07:24] Mellya tells how the study has changed rhino management in Tanzania. •[08:37] Mable and Mellya enumerate the caveats and limitations of the study. •[10:20] Conclusion. About Our Guests: Barbara Mable Professor University of Glasgow Ronald Mellya Park Warden Tanzania National Parks View related content here: https://www.pnas.org/doi/abs/10.1073/pnas.2414412122 Follow us on Spotify, Apple Podcasts, or wherever you get your podcasts for more captivating discussions on scientific breakthroughs! Visit Science Sessions on PNAS.org: https://www.pnas.org/about/science-sessions-podcast Follow PNAS: Twitter/X Facebook LinkedIn YouTube Sign up for the PNAS Highlights newsletter

Water and the possibility of life on Mars Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scientific community. Learn the behind-the-scenes story of work published in the Proceedings of the National Academy of Sciences (PNAS), plus a broad range of scientific news about discoveries that affect the world around us. In this episode, researchers explain what we know about the potential for water and life on Mars and what we might learn from analysis of returned samples. In this episode, we cover: •[00:00] Introduction •[01:04] Mark Thiemens explains the importance of bringing samples from Mars back to Earth. •[02:37] Arya Udry explains the current gaps and limitations in the geological record provided by Martian meteorites. •[03:55] Bruce Jakosky explains what we currently know about the presence and history of water on Mars. •[05:26] Monica Grady explains how analyzing volatile species in Martian samples could provide insight into the planet's past climate. •[06:58] Rachel Slank describes the potential presence of liquid brines on Mars. •[08:27] Vashan Wright used recordings from a seismometer onboard NASA's InSight lander to estimate the volumes of liquid water that might be contained in the Martian mid-crust. •[10:14] Mark Sephton explains what biomarkers are and what kinds we might expect to find in Martian samples. •[11:34] Caroline Freissinet describes the discovery of long-chain organic molecules on Mars and the difficulties of conclusively identifying organic molecules as biomarkers. •[13:32] Thiemens explains the potentially far-reaching value of continuing to support the Mars Sample Return mission. •[14:37] Final thoughts and conclusion. About Our Guest: Mark Thiemens Distinguished Professor of Chemistry and Biochemistry University of California at San Diego Arya Udry Associate Professor – Graduate coordinator University of Nevada, Las Vegas Bruce Jakosky Professor Emeritus University of Colorado Boulder Monica Grady Professor Emirita Open University Rachel Slank Postdoctoral Fellow Lunar and Planetary Institute Vashan Wright Assistant Professor University of California, San Diego Mark Sephton Professor Imperial College London Caroline Freissinet Researcher Laboratory for Atmospheres, Observations, and Space French National Centre for Scientific Research View related content here: https://www.pnas.org/doi/10.1073/pnas.2421996121 https://www.pnas.org/doi/10.1073/pnas.2415280121 https://www.pnas.org/doi/full/10.1073/pnas.2404254121 https://www.pnas.org/doi/full/10.1073/pnas.2321080121 https://www.pnas.org/doi/full/10.1073/pnas.2404260121 https://www.pnas.org/doi/full/10.1073/pnas.2321067121 https://www.pnas.org/doi/full/10.1073/pnas.2409983121 https://www.pnas.org/doi/full/10.1073/pnas.2404256121 https://www.pnas.org/doi/full/10.1073/pnas.2420580122 Follow us on Spotify, Apple Podcasts, or wherever you get your podcasts for more captivating discussions on scientific breakthroughs! Visit Science Sessions on PNAS.org: https://www.pnas.org/about/science-sessions-podcast Follow PNAS: Twitter/X Facebook LinkedIn YouTube Sign up for the PNAS Highlights newsletter