Particles of Thought

Fame can hijack the brain like a drug—activating the same reward circuits that fuel a relentless chase for dopamine highs. Neuroscientist Heather Berlin reveals the antidote—and why even social media fame can trigger this cycle.For more, check out the extended interview with Heather Berlin.Learn more about NOVA and subscribe to our YouTube channel.

Fossilization isn’t luck - it’s geology. Paleobotanist Kirk Johnson explains how fossils only form in certain conditions, the tricks to finding them, and why one fossil leaf can lead to thousands more. For more, check out the extended interview with Kirk Johnson.Learn more about NOVA and subscribe to our YouTube channel.

Speech is rare in the animal kingdom because it requires a very specific brain architecture. Neuroscientist Erich Jarvis explains how duplicating neural pathways for movement unlocked language, dancing, and even advanced problem-solving in more than just humans.For more, check out the extended interview with Erich Jarvis. Learn more about NOVA and subscribe to our YouTube channel.

How does evolution invent entirely new things, like limbs, wings, and venom? Evolutionary biologist Sean B. Carroll joins us to reveal the hidden rules behind nature’s creativity and the genetic toolkit that makes it possible. Carroll explains how the same set of genes can build wildly different creatures — from fruit flies to lobsters — simply by rewiring their genetic circuits. Discover why developmental biology holds the key to understanding evolution, how snake venom evolved, and why medicines like GLP-1 drugs and statins trace their origins to nature’s own innovations. Plus, what the emergence of new species tells us about life’s future and the surprising power of evolution to repurpose old parts in new ways. Learn more about NOVA and subscribe to our YouTube channel. —————————Guest Bio: Sean B. Carroll is a renowned evolutionary biologist and author whose work has inspired a deeper public understanding of evolution and the natural world. He is an Investigator at Howard Hughes Medical Institute (HHMI), where he was formerly Head of HHMI Tangled Bank Studios, and led the Department of Science Education from 2010-2023. He is also a Professor of Biology at the University of Maryland. His research focuses on genes that influence the evolution of animal diversity.

From legs on heads to missing eyes, fruit fly mutations exposed the genetic toolkit that builds all animals. Evolutionary Biologist Sean B. Carroll shows how these discoveries rewrote our understanding of evolution.Learn more about NOVA and subscribe to our YouTube channel.

From snakes to jellyfish, venom is one of evolution’s most lethal inventions. Evolutionary Biologist Sean B. Carroll reveals how this deadly innovation emerged—and the new science behind antivenom inspired by nature’s own defenses.Learn more about NOVA and subscribe to our YouTube channel.

The edge of a black hole isn’t what you think. Astrophysicist Janna Levin dives into the event horizon, the one-way transition where space and time warp so much that escape becomes as impossible as reversing the clock.For more, check out the extended interview with Janna Levin.Learn more about NOVA and subscribe to our YouTube channel.

There’s no single ‘smoking gun’ for life beyond Earth. Microbiologist Peter Girguis explains the subtle fingerprints scientists hunt for—and why finding them on Mars could change everything.For more, check out the extended interview with Peter Girguis.Learn more about NOVA and subscribe to our YouTube channel.

Scientists are editing genes for human speech into mice to see if they can learn vocal patterns. Neuroscientist Erich Jarvis explains how this could unlock not just speech—but entirely new ways of thinking.For more, check out the extended interview with Erich Jarvis. Learn more about NOVA and subscribe to our YouTube channel.

Can we bring extinct species back to life? Evolutionary biologist Beth Shapiro claims we just did. As Chief Science Officer at Colossal, her team made headlines in spring 2025 with the announcement of the de-extinction of the dire wolf. She takes us behind the headlines to explain how this is no “Jurassic Park” fantasy. She breaks down exactly how her team used ancient DNA, CRISPR genome editing, and the genomes of modern relatives to bring back lost traits and create animals capable of thriving in today’s ecosystems. Along the way, she dives into the surprising challenges of this work — from the quest for artificial wombs to the ethics of genetic engineering — and reveals how the same tools powering de-extinction are already helping endangered species survive. Learn more about NOVA and subscribe to our YouTube channel. —————————Guest Bio: Beth Shapiro is an evolutionary biologist and Chief Science Officer at Colossal, a company notably responsible for the de-extinction of the dire wolf. She is also a professor of Ecology and Evolutionary Biology at UC Santa Cruz. Her research focuses on species evolution and the continued impact of human activities, considering questions about domestication, speciation and pathogen evolution. She is also exploring techniques to recover trace amounts of DNA from samples and the possible role of genomic technologies in the fields of conservation and medicine.Timestamps(00:00) What is De-Extinction? Reviving the Dire Wolf(29:45) Ethics and Backlash for Cloning (38:10) Modifying DNA to Bring Species Back to Life(45:31) The Future of De-Extinction(54:30) Credits