Science (Audio)

Genetic data is transforming the understanding of our own species and refining historical chapters at different scales around the globe. However, despite the globalization of biotechnologies to analyze the human genome, indigenous populations from the Americas and Oceania remain underrepresented in large-scale genomic studies. Andrés Moreno-Estrada, Cinvestav, discusses recent efforts to characterize the genetic profile of Indigenous Americans throughout the analysis of ancient and modern DNA, as well as their relationship within and beyond the continent, including the possibility of prehistoric contacts with Pacific Islanders. This topic poses challenges and opportunities to adequately study human diversity not only for the benefit of genetic research and science, but also for the benefit of the local communities, which are bearers of a unique evolutionary history that has been recorded in their DNA. This rapidly evolving field also raises questions about the best practices when studying the DNA of underrepresented ancestries while conducting cutting-edge science in a more equitable way. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Science] [Show ID: 41201]

Large-scale optimization and machine learning shape modern data science, and Courtney Paquette, Ph.D., McGill University, studies how to design and analyze algorithms for large-scale optimization problems motivated by applications and data science. Paquette draws on probability, complexity theory, and convex and non-smooth optimization, and examines scaling limits of stochastic algorithms. Speaking with Saura Naderi, UC San Diego, Paquette describes an unconventional path from finance to pure mathematics and explains how persistence and comfort with uncertainty support long-term research. She highlights the challenge of building missing foundations while advancing through graduate training, and she connects that experience to the realities of doing original work. Paquette also reflects on rapid progress in machine learning and frames AI systems as tools that can be used thoughtfully. Series: "Science Like Me" [Science] [Show ID: 41119]

The human genetic history of South Asia has been shaped by its pivotal location at the crossroads of East and West Eurasia, dramatic landscapes such as the Himalayas, and longstanding socio-cultural practices like endogamy. A consequence is the diversity of East and West Eurasian genetic ancestral lineages found in South Asians today. Maanasa Raghavan, professor at the University of Chicago, explains that the increasing genome-wide data from ancient and present-day humans are providing emerging insights into the demographic processes that underlie present-day genetic diversity of South Asians and how they interface with evidence from archaeology, anthropology, linguistics, and oral histories. Human history in South Asia is also closely intertwined with the animals that humans domesticated, traded, and moved with them, offering yet another window into the dynamics of human mobility and connectivity in the past. Raghavanon's talk focuses on ancient and modern DNA insights into the origins of present-day human genetic diversity in South Asia, evolutionary history of domesticates, and broader implications for our understanding of human movements and interactions across Eurasia. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Science] [Show ID: 41200]

Stem cell science is reshaping treatment for complex disorders of the brain and spinal cord. Researchers develop cell based therapies to replace lost dopaminergic neurons in Parkinson’s disease, fill gaps across spinal cord injuries, and calm seizure networks in refractory epilepsy by restoring the balance of inhibition and excitation. Teams test immune cell therapies against Epstein Barr virus infected B cells in multiple sclerosis and collaborate to move treatments across the blood brain barrier to reach diseased cells. Clinicians combine imaging in the operating room, surgical tools, and research on biological age and the pace of aging to understand disease and guide treatment. Patient advocates describe challenges and hopes for better options, and contemporary art reflects on perception in digital and physical worlds. Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 40992]

Ancient DNA has revolutionized the study of the human past, providing unprecedented insights into ancient migrations and interactions among populations. Central Asia, due to its geographic location between Europe and Asia, has seen experienced diverse human and hominin migrations, which have been a focus of genetic, archaeological, linguistic, and historical research. Ainash Childebayeva, professor at the University of Texas at Austin, discusses recent advances in population genetics which have revealed the complex ancestry of Central Asian groups, both modern and ancient. Significant progress has also been made in understanding the role of natural selection in shaping genetic variation across the region. Childebayeva presents recent developments in our knowledge of Central Asia’s genetic history, integrating findings from both modern and ancient genomic studies. Additionally, she highlights the selective pressures that have influenced the genomes of Central Asians through time, shedding light on the dynamic interplay between admixture, adaptation, and cultural change. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Science] [Show ID: 41199]

We’re surrounded by digital devices — from phones and tablets to streaming platforms and social media. In this excerpt, Kristy Hamilton, Assistant Professor in the Department of Communication at UCSB, shares findings on how cognitive self-esteem can change if a person is using a personal mobile device. Series: "GRIT Talks" [Science] [Show ID: 41214]

Over the past decade, archaeogenetics has analyzed more than 15,000 ancient genomes spanning 45,000 years of western Eurasian prehistory, uncovering dozens of migrations that reshaped Europe. Johannes Krause, Max Planck Institute, traces the earliest, unsuccessful attempts of modern humans to settle Europe after leaving Africa around 50,000 years ago, when they also interbred with Neandertals. Krause examines two major genetic turnovers of the Neolithic: the spread of early farmers from Anatolia about 8,000 years ago, who brought agriculture and domesticated animals and later mixed with indigenous hunter-gatherers; and the arrival of mobile herders from the Pontic steppe around 5,000 years ago, who introduced pastoralism and possibly Indo-European languages. Finally, he considers migrations triggered by the collapse of the Roman Empire, showing how large-scale mobility created the multiple ancestral strands found in modern Europeans. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Science] [Show ID: 41198]

Dramatic advances in ancient DNA technologies have revolutionized our understanding of the human past. Since the publication of the first ancient human genomes in 2010, the field of archaeogenomics has grown at an astonishing pace, and today the genomes of more than 10,000 ancient humans have been sequenced. Kicking off this symposium are CARTA Co-Director and Salk Institute President Jerry Joyce and event co-chair Johannes Krause. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Science] [Show ID: 41194]

How do most organisms in the natural world communicate? It's through the language of chemistry. Scripps Institution of Oceanography marine biologists Bradley Moore and Natalie Grayson explore how ocean life uses molecules as a language. Examples include a pigment that lets squid and octopus change color for camouflage, a coral and its microbial partners that produce biologically active compounds, and a chemical now in phase three human clinical trials to treat glioblastoma, an aggressive cancer of the brain. Their research has applications for new materials in biotech, and improving the food supply and human health. Series: "Jeffrey B. Graham Perspectives on Ocean Science Lecture Series" [Science] [Show ID: 41190]

How do you navigate a nonlinear, “squiggly line” career in science and public health? Dr. Katelyn Jetelina, an epidemiologist and scientific communicator, explores challenges of science communication within academia—from cultural resistance to misaligned incentives—and why so much vital research never reaches the public. Joined by Dr. John Schwartzberg, Professor Emeritus, School of Public Health, they discuss the growing opportunities for scientists both within and beyond academia, and what needs to change to better support public impact across all career paths. Series: "UC Berkeley Graduate Lectures" [Health and Medicine] [Science] [Education] [Show ID: 41067]

We’re surrounded by digital devices — from phones and tablets to streaming platforms and social media. In this excerpt, Kristy Hamilton, Assistant Professor in the Department of Communication at UCSB, shares research on how digital media shapes the way we see ourselves and the way we behave. Series: "GRIT Talks" [Science] [Show ID: 41215]

The Kazakh and Mongolian Steppes span 5,000 kilometers west to east along the northern latitude of Asia. This unique ecozone allowed rapid movements of people, animals, goods, and ideas across Eurasia since prehistory and harbored numerous polities of pastoralists that made tremendous impacts on human history. However, the region’s dynamic genetic history has been emerging only recently from archaeogenomic studies. Choongwon Jeong of Seoul National University discusses the current understanding of the region’s genetic history, including the divergent genetic history of the Kazakh and Mongolian Steppe populations, the genetic interaction between the steppe pastoralists and their neighbors, and a comparison between the genetic history of human and domesticated animal populations. The emerging genetic view illuminates the poorly recorded history of the Kazakh and Mongolian Steppes and provides an interconnected perspective on the history of Eurasia. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Science] [Show ID: 41197]

Humans have a deep and complex relationship with microbes. Beyond disease, microbes also profoundly shape human health and behavior through their activity in the microbiome and their diverse roles in food and cuisine. And yet we know very little about the origin, evolution, or ecology of the trillions of microorganisms that call us home. Christina Warinner of Harvard University discusses recent advances in genomic and proteomic technologies that are opening up dramatic new opportunities to investigate the complex and diverse microbial communities that have long inhabited our human bodies and our food systems - both in sickness and in health. From infectious disease to the microbiome, microbes are the invisible and often overlooked figures that have profoundly shaped human culture and influenced the course of human history. Warinner focuses on the long arc of human-microbial relationships preserved by ancient DNA over the past 100,000 years, and explores how emerging research on pathogen evolution and the recent loss of commensal microbes is changing how we understand human health – both today and in the past. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Science] [Show ID: 41196]

David Gokhman of the Weizmann Institute of Science explores how changes in gene regulation shaped recent human evolution. His team used massively parallel reporter assays in skeletal and neural cells to test 71,443 genetic variants that distinguish Neanderthals and Denisovans from modern humans, building a catalog that reveals hundreds of noncoding variants that alter gene expression. The work uncovers evolutionary trends and examples of convergent evolution, including an enhancer of KDM8, a gene involved in tumor progression, that was completely silenced in both archaic and modern human lineages through different mechanisms: motif disruption in Neanderthals and Denisovans, and hypermethylation in modern humans. Gokhman also introduces a way to reconstruct anatomical profiles from DNA sequence and methylation, using it to model Denisovan anatomy and scan the fossil record. The results suggest that the Harbin and Dali fossils were likely Denisovans, while Kabwe may have been related to the ancestor of Neanderthals and Denisovans, helping to clarify the regulatory changes underlying human evolution. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Science] [Show ID: 41195]

Peter Godfrey-Smith, Professor of History and Philosophy of Science at the University of Sydney, explores the evolutionary roots of consciousness by surveying animal evolution and the emergence of felt experience in several lineages. He examines two central philosophical questions: how such experience might arise gradually, existing in partial forms, and whether it represents a single unified feature with variations or instead a cluster of distinct traits. Author of "Darwinian Populations and Natural Selection," and "Living on Earth: Forests, Corals, Consciousness and the Making of the World," Godfrey-Smith brings his expertise in philosophy of biology and mind to illuminate how consciousness may have emerged and why its origins remain a profound puzzle. Series: "UC Berkeley Graduate Lectures" [Humanities] [Science] [Show ID: 41065]

The sequencing of genomes from archaic humans, such as Neanderthals and Denisovans, has transformed our understanding of human evolutionary history. These ancient genomes reveal that modern humans did not evolve in isolation but interbred with now-extinct groups, leaving lasting genetic legacies. To date, genomic sequences from 31 archaic human individuals, including four sequenced to high coverage, have provided unprecedented insights into the population structure, social organization, and adaptation of this now-extinct lineages, allowing us to reconstruct our own evolutionary history and the mechanisms that led to modern human success. Diyendo Massilani of Yale University School of Medicine reviews nearly three decades of research on archaic human DNA and what we have learned about how these groups lived, as well as how admixture between different lineages may have contributed both to the extinction of archaic humans and the thriving of modern humans. Ultimately, ancient genomes show that the success of our species was not predetermined but forged through encounters, exchanges, and adaptations, and that the legacies of archaic humans live on in our biology today, continuing to influence what it means to be human. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Science] [Show ID: 41193]

Alejandro Sánchez Alvarado, Ph.D., argues that real progress in understanding regeneration comes from studying whole organisms rather than cells grown under artificial conditions. Sánchez Alvarado shows how observations from intact animals reveal organizing rules that narrow laboratory systems can miss. He presents evidence that stem cells in a studied animal lack detectable junctions with neighboring cells and instead respond to signals that travel across tissues. Sánchez Alvarado links this communication to extracellular vesicles that carry RNA and to metabolic support involving creatine, highlighting how distant tissues influence repair. Using imaging and molecular analyses, he tracks how signals move through the body and how specific cell populations change state during recovery. Sánchez Alvarado concludes that broad, comparative research is essential for uncovering general principles that govern how adult tissues restore form and function. Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 40454]

Climate investor and philanthropist Tom Steyer, recipient of the 2025 Charles David Keeling Memorial Lecture, talks about the current and future state of energy. In a conversation with Scott Lewis of Voice of San Diego, Steyer argues that capitalism and policy must work together at scale, and highlights the marketplace rise of renewables like solar and EVs alongside challenges like slow fossil-plant retirement, grid constraints, and the need for longer-duration storage. He also discusses emerging options such as advanced geothermal and nuclear. The Keeling Memorial Lecure is given by a prominent member of the global change community able to speak on topics that reflect the legacy of Keeling's work. [Science] [Business] [Show ID: 41034]

The genome sequences of Neandertals and Denisovans have provided a wealth of new information about the origins, migrations, and interactions of ancient humans. These genomes have revealed that mixture between hominin groups was common: all modern humans outside Africa carry around 2% Neandertal DNA from a single major episode of Neandertal gene flow, while the ancestors of present-day Asians and Oceanians also met and mixed with multiple, genetically distinct Denisovan populations. Archaeological evidence suggests multiple dispersals of modern humans out of Africa, with early fossils identified in East and Southeast Asia over 50 thousand years ago. In contrast, genomic studies indicate that all present-day non-African populations descend primarily from a single dispersal after ~50 ka, though the migration routes of ancestral populations across Eurasia and Oceania remain unclear. Janet Kelso, professor at Max Planck Institute for Evolutionary Anthropology, shows how using the distribution of Neandertal and Denisovan ancestry in ancient and present-day modern humans can determine when, where and how often modern and archaic humans met and mixed. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Science] [Show ID: 41192]

An in vivo brain organoid platform reveals how human neurons and glia interact across development, aging, and disease. Fred H. Gage, Ph.D., generates three dimensional organoids from induced pluripotent stem cells and examines their maturation, synapses, and network activity with two-photon imaging and single-cell profiling. Gage integrates human microglia and astrocytes to study immune signaling, injury responses, and support functions that shape circuit behavior. Transplantation enables vascularization, reduces cell death, and yields features consistent with a blood brain barrier. Analyses identify diverse astrocyte types and trajectories, while patterns of tau expression inform Alzheimer’s disease modeling. Gage also converts adult fibroblasts into age retaining neurons that assemble into 3D spheroids, creating complementary models to connect genes, cells, and circuits with pathology and to guide strategies for prevention and therapy. Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 41160]