“What good is half a wing?” That’s the rhetorical question often asked by people who have trouble accepting Darwin’s theory of evolution by natural selection. Of course it’s a very answerable question, but figuring out what exactly the answer is leads us to some fascinating biology. Neil Shubin should know: he is the co-discoverer of Tiktaalik Roseae, an ancient species of fish that was in the process of learning to walk and breathe on land. We talk about how these major transitions happen — typically when evolution finds a way to re-purpose existing organs into new roles — and how we can learn about them by studying living creatures and the information contained in their genomes.Support Mindscape on Patreon.Neil Shubin received his Ph.D. in organismic and evolutionary biology from Harvard University. He is currently the the Robert Bensley Distinguished Service Professor and Associate Dean of Biological Sciences at the University of Chicago. He is a member of the National Academy of Sciences and the American Philosophical society. His first book, Your Inner Fish, was chosen by the National Academy of Sciences as the best science book of 2009, and was subsequently made into a TV special. His new book is Some Assembly Required: Decoding Four Billion Years of Life, from Ancient Fossils to DNA.Web siteUniversity of Chicago web pageGoogle Scholar publicationsWikipediaAmazon author pageYour Inner Fish on PBSTwitterSee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

If you tell me that one of the world’s leading neuroscientists has developed a theory of how the brain works that also has implications for the origin and nature of life more broadly, and uses concepts of entropy and information in a central way — well, you know I’m going to be all over that. So it’s my great pleasure to present this conversation with Karl Friston, who has done exactly that. One of the most highly-cited neuroscientists now living, Friston has proposed that we understand the brain in terms of a free energy principle, according to which our brains are attempting to model the world in such a way as to minimize the amount of surprise we experience. It’s a bit more complicate than that, but I think we made great headway in explicating some very profound ideas in a way that should be generally understandable.Support Mindscape on Patreon.Karl Friston received his medical degree from King’s College Hospital, London. He is currently Professor at the Institute of Neurology, University College London, and Wellcome Principal Research Fellow and Scientific Director of the Wellcome Trust Centre for Neuroimaging. Among his major contributions are statistical parametric mapping, voxel-based morphometry, and dynamical causal modeling. He is a Fellow of the Royal Society, of the Academy of Medical Science, and of the Royal Society of Biology. Among his awards are the Young Investigators Award in Human Brain Mapping, the Minerva Golden Brain Award, the Weldon Memorial Prize, the Charles Branch Award, and the Glass Brain Award for human brain mapping.Web pageGoogle Scholar publicationsTalk on “I Am, Therefore I Think”Article on “The Free-Energy Principle: A Unified Brain Theory?”WikipediaSee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

Anyone who has read histories of the Cold War, including the Cuban Missile Crisis and the 1983 nuclear false alarm, must be struck by how incredibly close humanity has come to wreaking incredible destruction on itself. Nuclear war was the first technology humans created that was truly capable of causing such harm, but the list of potential threats is growing, from artificial pandemics to runaway super-powerful artificial intelligence. In response, today’s guest Martin Rees and others founded the Cambridge Centre for the Study of Existential Risk. We talk about what the major risks are, and how we can best reason about very tiny probabilities multiplied by truly awful consequences. In the second part of the episode we start talking about what humanity might become, as well as the prospect of life elsewhere in the universe, and that was so much fun that we just kept going.Support Mindscape on Patreon.Lord Martin Rees, Baron of Ludlow, received his Ph.D. in physics from University of Cambridge. He is currently Emeritus Professor of Cosmology and Astrophysics at the University of Cambridge, as well as Astronomer Royal of the United Kingdom. He was formerly Master of Trinity College and President of the Royal Society. Among his many awards are the Heineman Prize for Astrophysics, the Gruber Prize in Cosmology, the Crafoord Prize, the Michael Faraday Prize, the Templeton Prize, the Isaac Newton Medal, the Dirac Medal, and the British Order of Merit. He is a co-founder of the Centre for the Study of Existential Risk.Web pageInstitute for Astronomy, Cambridge, web pageGoogle Scholar publicationsAmazon.com author pageWikipediaCentre for the Study of Existential RiskSee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

It’s hard to make decisions that will change your life. It’s even harder to make a decision if you know that the outcome could change who you are. Our preferences are determined by who we are, and they might be quite different after a decision is made — and there’s no rational way of taking that into account. Philosopher L.A. Paul has been investigating these transformative experiences — from getting married, to having a child, to going to graduate school — with an eye to deciding how to live in the face of such choices. Of course we can ask people who have made such a choice what they think, but that doesn’t tell us whether the choice is a good one from the standpoint of our current selves, those who haven’t taken the plunge. We talk about what this philosophical conundrum means for real-world decisions, attitudes towards religious faith, and the tricky issue of what it means to be authentic to yourself when your “self” keeps changing over time.Support Mindscape on Patreon.L.A. (Laurie) Paul received her Ph.D. in philosophy from Princeton University. She is currently professor of philosophy and cognitive science at Yale University. She has worked extensively on causation, the philosophy of time, mereology, and transformative experience. She has won fellowships from the Guggenheim Foundation, the National Humanities Center, and the Australian National University. Among her books are the monograph Transformative Experience; she is currently working on a popular-level book on this theme.Web siteYale web pagePhilPeople profileGoogle Scholar publicationsAmazon.com author pageWikipediaTwitterSee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

Nations generally want their economies to be rich, robust, and growing. But it’s also important to person to ensure that wealth doesn’t flow only to a few people, but rather that as many people as possible can enjoy the benefits of a healthy economy. As is well known, the best way to balance these interests is a contentious subject. On one side we might find free-market fundamentalists who want to let supply and demand set prices and keep government interference to a minimum, while on the other we might find enthusiasts for very strong government control over all aspects of the economy. Suresh Naidu is an economist who has delved deeply into how economic performance affects and is affected by other notable social factors, from democracy to revolution to slavery. We talk about these, as well as how concentrations of economic power in just a few hands — monopoly and its cousin, monopsony — can distort the best intentions of the free market.Support Mindscape on Patreon.Suresh Naidu received his Ph.D. in economics from the University of California, Berkeley. He is currently professor of economics and international affairs at Columbia University as well as a fellow at Roosevelt Institute, external faculty at the Santa Fe Institute, and a research fellow at National Bureau of Economic Research. His awards include a Sloan Research Fellowship and the “Best Ph.D. Advisor Award” from the Columbia Association of Graduate Economics Students.Columbia School of International and Public Affairs pageSanta Fe Institute pageEquitable Growth pageGoogle Scholar publicationsThe Economy online textbookTwitterSee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

The Greek statesman Demosthenes is credited with saying “I am a citizen of the world,” and the idea that we should take a cosmopolitan view of our common humanity is a compelling one. Not everyone agrees, however; in the words of former British Prime Minister Theresa May, “If you are a citizen of the world, you are a citizen of nowhere.” On the other side of the political spectrum, groups who share a feature of identity — race, ethnicity, gender, sexuality, and others — find it useful to band together to make political progress. Kwame Anthony Appiah is a leading philosopher and cultural theorist who has thought carefully about the tricky issues of cosmopolitanism and identity. We talk about how identities form, why they matter, and how to negotiate the difficult balance between being human and being your particular self.Support Mindscape on Patreon.Kwame Anthony Appiah received his Ph.D. in philosophy from Cambridge University. He is currently Professor of Philosophy and of Law at New York University. He is the author of numerous academic books as well as several novels. He is a fellow of the American Academy of Arts and Sciences, and is the recipient of a number of major awards, including the National Humanities Medal of the United States. He currently writes the New York Times Magazine column “The Ethicist“, and frequently writes for The New York Review of Books. (Note that in the podcast intro I mistakenly said he was “born and raised” in Ghana; he was actually born in London, moving to Ghana when he was six months old.)Web siteNYU web pageGoogle Scholar publicationsAmazon.com author pageTalk on “Beyond Identity”WikipediaTwitterSee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

The Convention on Psychotropic Substances was a 1971 United Nations treaty that placed strong restrictions on the use of psychedelic drugs — not only on personal use, but medical and scientific research as well. Along with restrictions placed by individual nations, it has been very difficult for scientists to study the effects of psychedelics on the brain, despite indications that they might have significant therapeutic potential. But this has gradually been changing, and researchers like Robin Carhart-Harris have begun to perform controlled experiments to see how psychedelics affect the brain, and what positive uses they might have. Robin and I talk about how psychedelics work, how they can help with conditions from addiction to depression, and how they can help people discover things about themselves.Support Mindscape on Patreon.Robin Carhart-Harris received his Ph.D. in psychopharmacology from the University of Bristol. He is currently the Director of the Centre for Psychedelic Research in the Department of Brain Sciences at Imperial College London, and holds an honorary position at the University of Oxford. His research involves functional brain imaging studies with psilocybin (magic mushrooms), LSD, MDMA (ecstasy) and DMT (ayahuasca), plus a clinical trial of psilocybin for treatment-resistant depression.Web siteCentre for Psychedelic ResearchGoogle Scholar pageTalk on Psychedelics: Lifting the VeilTwitterSee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

People have always disagreed about politics, passionately and sometimes even violently. But in certain historical moments these disagreements were distributed without strong correlations, so that any one political party would contain a variety of views. In a representative democracy, that kind of distribution makes it easier to accomplish things. In contrast, today we see strong political polarization: members of any one party tend to line up with each other on a range of issues, and correspondingly view the other party with deep distrust. Political commentator Ezra Klein has seen this shift in action, and has studied it carefully in his new book Why We’re Polarized. We talk about the extent to which the apparent polarization is real, how we can trace its causes, and whether there’s anything we can do about it.Support Mindscape on Patreon.Ezra Klein received a B.A. in political science from the University of California, Los Angeles. He is currently the editor-at-large and founder of Vox. As a writer and editor his work has appeared in/on The Washington Post, MSNBC, Bloomberg, The New York Review of Books, and The New Yorker. Among his awards are Blogger of the Year (The Week), 50 Most Powerful People in Washington DC (GQ), Best Online Commentary (Online News Association), and the Carey McWilliams Award (American Political Science Association).Vox profileThe Ezra Klein Show podcastWhy We’re PolarizedWikipediaTwitterSee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

Physics is simple; people are complicated. But even people are ultimately physical systems, made of particles and forces that follow the rules of the Core Theory. How do we bridge the gap from one kind of description to another, explaining how someone we know and care about can also be “just” a set of quantum fields obeying impersonal laws? This is a hard question that comes up in a variety of forms — What is the “self”? Do we have free will, the ability to make choices? What are the moral and ethical ramifications of these considerations? Jenann Ismael is a philosopher at the leading edge of connecting human life to the fundamental laws of nature, for example in her recent book How Physics Makes Us Free. We talk about free will, consciousness, values, and other topics about which I’m sure everyone will simply agree.Support Mindscape on Patreon.Jenann Ismael received her Ph.D. in philosophy from Princeton University. She is currently Professor of Philosophy at Columbia University. Her work includes both the foundations of physics (spacetime, quantum mechanics, symmetry) and the philosophy of mind and cognition. She has been awarded fellowships from Stanford University, the Australian Research Council, the Scots Philosophical Association, and the Center for Advanced Study in Social and Behavioral Sciences, as well as an Essay Prize from the British Society for the Philosophy of Science.Web siteColumbia web pagePhilPeople profileAmazon author pageCloser to Truth interviewWikipedia“Well-Being and Time,” David Velleman (mentioned in the episode)See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

We are all alive, but “life” is something we struggle to understand. How do we distinguish a “living organism” from an emergent dynamical system like a hurricane, or a resource-consuming chemical reaction like a forest fire, or an information-processing system like a laptop computer? There is probably no one crisp set of criteria that delineates life from non-life, but it’s worth the exercise to think about what we really mean, especially as the quest to find life outside the confines of the Earth picks up steam. Sara Imari Walker planned to become a cosmologist before shifting her focus to astrobiology, and is now a leading researcher on the origin and nature of life. We talk about what life is and how to find it, with a special focus on the role played by information and computation in living beings.Support Mindscape on Patreon.Sara Imari Walker received her Ph.D. in physics from Dartmouth college. She is currently Associate Professor in the School of Earth and Space Exploration at Arizona State University, Deputy Director of the Beyond Center for Fundamental Concepts in Science, and Associate Director of the ASU-Santa Fe Institute Center for Biosocial Complex Systems. She is the co-founder of the astrobiology social network SAGANet, and serves on the Board of Directors for Blue Marble Space.Web siteGoogle Scholar pageAsk an Astrobiologist interviewTalk on A Theory of LifeWikipediaTwitterSee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.