Chocolate may fill grocery store shelves around the world, but the raw product that powers chocolate is far more selective. The majority of chocolate farms are found in West Africa and South America – just 20 degrees north or south of the equator. Each farm produces chocolate of a different flavor. Some cocoa tastes fruitier; others, more floral. Nutty. Earthy. Spicy. But what drives these different flavor profiles? And can it be recreated in a lab? A team led by scientists at the University of Nottingham in the UK sought to find out and published their results in the journal Nature Microbiology this week. Curious about other ways science intersects with food? Email us at shortwave@npr.org . Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave . Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy…

Thirty years ago, park rangers reintroduced grey wolves into Yellowstone National Park. They wanted to restore the ecosystem and get the elk population, which had decimated the plant community, in check. And it worked – or so the popular narrative suggests. But is it really so simple? Today on the show, we explore how the Yellowstone ecosystem has changed since wolves returned and whether those changes can really be pinned solely on wolves. Plus, how the narrative of the Yellowstone wolf legacy could affect wolf reintroduction elsewhere. Curious about other science controversies? Email us at shortwave@npr.org . Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave . Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy…

Imagine, you’re a toxic toad hanging around South America. No other animals are gonna mess with you, right? After all, you’re ~toxic~! So if anyone tries to eat you, they’ll be exposed to something called a cardiotonic steroid — and may die of a heart attack. Well, unfortunately, for you, some animals have developed adaptations to these toxic steroids. Evolutionary biologist Shabnam Mohammadi has spent her career studying how these adaptations work — and says even humans have used these toxins to their advantage since ancient Egypt. So today on Short Wave, we get a little… toxic (cue Brittney Spears). Host Regina G. Barber talks to Shabnam about how some predators can get away with eating toxic prey. Curious about biology? Email us at shortwave@npr.org. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave . Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy…

Scientists have mapped less than 30% of the world's seafloor. Experts say that getting that number up to 100% would improve everything from tsunami warnings to the Internet and renewable energy. That's why there's currently a global effort to create a full, detailed map of the seabed by 2030. On today's Sea Camp episode, we talk to Dawn Wright , a marine geographer and chief scientist at the Environmental Systems Research Institute (Esri) about this effort. We have a newsletter that lets you go even deeper with the marine research each week of Sea Camp . You can sign up here! Curious about ocean science? Email us at shortwave@npr.org . Listen to Short Wave on Spotify and Apple Podcasts . Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy…

In this Back To School episode we consider the "List of Life": the criteria that define what it is to be a living thing. Some are easy calls: A kitten is alive. A grain of salt is not. But what about the tricky cases, like a virus? Or, more importantly, what about futuristic android robots? As part of our Black History Month celebration, developmental biologist Crystal Rogers and Short Wave co-host Regina G. Barber dig into what makes something alive, and wade into a Star-Trek-themed debate. Listen to Short Wave on Spotify and Apple Podcasts . Is there something you'd like us to cover? Email us at shortwave@npr.org. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy…

Neurotic, anxious robots like C-3P0 from Star Wars' C-3P0 and Marvin from The Hitchhiker's Guide to the Galaxy are a staple of science fiction — but they're not as common in the real world. Most of the time, the chatbots and artificial intelligence "robots" we encounter are programmed to be extraverted, confident and cheerful. But what if that changed? NPR science correspondent Nell Greenfieldboyce dives into the world of robot personality research and talks to a team of researchers that are experimenting with a very different kind of robot temperament. Read more of Nell's reporting on the topic here . Interested in more science news? Let us know at shortwave@npr.org. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave . Love podcasts? For handpicked recommendations every Friday, subscribe to NPR's Pod Club . Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy…

A Chinese scientist, He Jiankui, made a shocking announcement to the world in 2018: He had secretly engineered the birth of the first gene-edited babies. The birth of the twins was seen as reckless and unethical by the scientific community. That’s because, among other things, the CRISPR gene-editing technique Jiankui used was so new. NPR science correspondent Rob Stein has been following the controversial world of gene-editing and human reproduction, including some companies’ recent quests to push gene-editing technology forward. Read more of Rob Stein’s reporting on the topic here . Interested in more science news? Let us know at shortwave@npr.org. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave . Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy…

How did life start on Earth? The answer is a big scientific mystery scientists are actively investigating. After talking with many scientists, host Regina G. Barber found that an abundance of water on Earth is most likely key, in some way, to the origin of life — specifically, in either deep sea hydrothermal vents or in tide pools. It's for this reason some scientists are also exploring the potential for life in so-called "water worlds" elsewhere in the solar system, like some of the moons of Jupiter and Saturn. This episode, Regina digs into two water-related hypotheses for the origin on life on Earth — and what that might mean for possible alien life. Have another scientific mystery you want us to cover on a future episode? Email us at shortwave@npr.org . Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave . Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy…

The human brain tends to slow down as we age — even healthy brains shrink. That can make learning and memory harder as people age. But some people’s brains shrink more slowly than their peers. This lucky group is called “SuperAgers.” They’re people aged 80 or older. But they have the memory abilities of someone 50-to-60 years old. This week in the journal Alzheimer's & Dementia, researchers from Northwestern University’s SuperAging Program summarized some of the secrets they’ve learned in the last 2.5 decades. Want to hear about more stories about human health and aging? Email us and let us know at shortwave@npr.org . Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave . Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy…

Every September, the small town of La Junta, Colorado puts on a whole festival to celebrate a beloved local animal: the tarantula! Around this time of year, thousands of mature male tarantulas start to migrate en masse – but until recently, scientists didn’t know what triggered them to move out of their cozy burrows. On today’s show, biologist Dallas Haselhuhn explains how they solved the mystery, and how climate change could affect future treks. Want to hear about more critter mysteries? Email us and let us know at shortwave@npr.org . Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave . Listen to Short Wave on Spotify and Apple Podcasts. This episode was produced by Berly McCoy and edited by Rebecca Ramirez. Tyler Jones checked the facts. Robert Rodriguez was the audio engineer. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy…

It’s no secret that stress isn’t good for you. But just how bad is it? Well, in the last few decades, scientists have linked psychological stress to changes in our DNA that look a lot like what happens on the molecular level as we age. Today on the show, host Regina G. Barber talks to freelance science journalist Diana Kwon about the latest research on stress and aging, including a new hypothesis for how your brain handles aging — and what science could do about all of it. Interested in more aging science? Let us know at shortwave@npr.org . Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave . Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy…

The bathypelagic zone of the ocean is 1,000 to 4,000 meters below the surface. Sometimes it's called the midnight zone because it's too deep for sunlight to reach. Most animals here are much smaller than their shallow-water counterparts. But occasionally, researchers find the rare deep sea giant: giant isopods, giant squids, colossal squids, sea spiders. While these giants sound like the subjects of some people's nightmares, deep sea biologist Craig McClain dreams about them. And today on the show, he helps unravel the mystery and research behind these creatures. SIGN UP FOR OUR SEA CAMP NEWSLETTER! WE WORKED SO HARD ON IT! Interested in more ocean mysteries? Let us know at shortwave@npr.org . Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave . Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy…

Last year, we reported how extreme weather events may be dwindling the future of chocolate. Just last week, we saw an inkling of that: The Hershey Company announced it would significantly raise the cost of its candy in the face of historically high cocoa prices. So, we're revisiting host Emily Kwong 's conversation with Yasmin Tayag , a food, health and science writer at The Atlantic. They get into the cocoa shortage: What's causing it, how it's linked to weather and poor farming conditions and what potential solutions exist. Plus, they enjoy a chocolate alternative taste test. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy…

A grayscale ballerina who appears to be moving. A human who can fit in a doll box. A black-and-white prism that appears to change shape when viewed from three different directions. Those are the top winners of the 2024 Best Illusion of the Year Contest , open to illusion makers around the world and co-created by neuroscientist Susana Martinez-Conde . Today on the show, we get lost in the magic and science of visual illusions. Have a neuroscience question? Email us at shortwave@npr.org . Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave . Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy…

Much of the country is deep in the middle of a heat wave right now. And every summer, Duane Stilwell's town in Arizona seems to get hotter. It has him worried — and he's not the only one. Since 1980, the average number of heat waves in the U.S has doubled and the average length of a heat wave season has increased from 40 days to 70 . Future summers, experts say, will be even hotter . But why exactly is that happening, and what can people do to protect themselves from the heat? This episode is part of Nature Quest , a monthly segment that answers listeners' questions about their local environment. If you have a question, send a voice memo to shortwave@npr.org that includes it, your name and where you live. We might make it into our next Nature Quest episode! Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave . Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy…