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Sixty-six million years ago, an asteroid wiped out the dinosaurs in a fiery global catastrophe. But we know little about how their successors, the mammals, recovered and took over the world. Now, hidden inside ordinary-looking rocks, an astonishing trove of fossils reveals a dramatic new picture of how rat-sized creatures ballooned in size and began to evolve into the vast array of species—from cheetahs to bats to whales to humans—that rule our planet today.

Amazing fossils reveal how mammals took over after an asteroid wiped out the dinosaurs.

Rise of the Mammals

NOVA Wonders What Are Animals Saying? Hero

From singing whales and squeaking bats to thumping spiders and clicking dolphins, the world is filled with the exotic sounds of our fellow creatures. What are they saying? While we believe language sets us apart, some animals demonstrate they can learn our language—like Chaser the dog, who recognizes hundreds of words, and Kanzi the bonobo, who appears to have a sophisticated understanding of spoken English. But can we decode their own communications? NOVA Wonders follows researchers around the globe who are deciphering an amazing array of clues that reveal how animals share information critical to their survival. Will we one day be able to write the bat dictionary or decode the hidden sign language of chimps? And what can these findings tell us about the roots of our own language?

Can we crack the code of animal communication?

What Are Animals Saying?

(This program is no longer available for online streaming.) A seven-mile-wide asteroid collided with Earth 66 million years ago, triggering a chain of events that coincide with the end of the dinosaurs. But experts have long debated exactly what happened when the asteroid struck and how the giant beasts met their end. Now, scientists have uncovered compelling new clues about the catastrophe—from New Jersey to the wilds of Patagonia—and an international expedition of scientists has drilled into the impact crater off the coast of Mexico, recovering crucial direct evidence of the searing energy and giant tsunami unleashed by the asteroid. Join NOVA as scientists piece together a chillingly precise unfolding of the Earth’s biggest cataclysm, moment by moment, and discover how our early mammalian ancestors managed to survive and repopulate the Earth. (Premiered December 27, 2017)

Experts drill into the impact crater of an asteroid that created a worldwide cataclysm.

Day the Dinosaurs Died

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Draper

Join NOVA producer Arlo Pérez as he unlearns a “fact” he was taught as a child.
Discover a piece of false information about monarch butterflies and Mexico’s Indigenous Purépecha community, and why tourism may be partly to blame.
The Big Lie about Monarch ButterfliesPublished: March 16, 2021Arlo Pérez: The problem with misinformation is that you don&#x27;t realize it&#x27;s wrong until you&#x27;ve made a complete fool of yourself. That&#x27;s what happened to me. I&#x27;ve been making a video about the monarch butterflies, the iconic insect that migrates from parts of Canada all the way to Michoacán in Western Mexico, where I grew up. To do so, I&#x27;m on my way to meet Teresa Madrigal, a prominent member of the Purépecha, an Indigenous community in the area.(Spanish Translation): Hello! Miss Teresa?I&#x27;m interested in speaking with Teresa because I&#x27;d always heard that monarchs were incredibly important for the Purépecha.Maria Teresa Madrigal Martínez: (Spanish Translation) There are only a few Purépecha kitchens left.And that the butterfly&#x27;s yearly return to Michoacán signifies the reincarnation of the Purépechas&#x27; ancestors&#x27; souls. Unfortunately, Teresa is about to inform me that the story that I&#x27;ve been working on for four months is wrong.Madrigal Martínez: (Spanish Translation) I&#x27;ve never seen them. I don&#x27;t even know them.Pérez: (Spanish Translation) And you haven&#x27;t seen one?Madrigal Martínez: (Spanish Translation) No, I don&#x27;t even know them. Maybe on a painting.Carlos García Mora: (Spanish Translation) No, no, no, no, no, no.Pérez: And she is not the only one.García Mora: (Spanish Translation) No. Of course, it is not the monarchs.Benjamín Lucas Juárez: (Spanish Translation) The butterflies are not within the Purépecha territory.García Mora: (Spanish Translation) Eh, just no.Pérez: Turns out, this belief belongs to completely different Indigenous communities, including at least two that are closer to the forest where the monarchs winter. But here&#x27;s the thing: I remember learning about the Purépecha and the monarchs in school only 45 minutes away from here. And I have seen this incorrect piece of information pop up in a bunch of different publications, both from the U.S. and from Mexico.And that got me thinking, how did this weirdly specific bit of misinformation get propagated?Juárez: (Spanish Translation) After the Revolution, Mexico had to rebuild itself as a country.Pérez: This is Benjamin Lucas Juarez, historian of Purépecha descent, who dedicated his life to studying the Purépecha culture. And he&#x27;s talking about the 1910 Mexican Revolution.Juárez: (Spanish Translation) While trying to build itself as a country, it was important to use symbols that unified the Mexican identity. I&#x27;m talking about the pyramids, the Aztecs, the Mayas, as a way to reclaim their past. But also to unify the country&#x27;s cultural identity into one or two cultures. In other words, one where there are no differences, no Indigenous languages, no different clothing, no different celebrations/Pérez: Just one unifying Mexican identity. But in a country with over 65 Indigenous communities, and more than 360 languages, this unification would come at the cost of placing few cultures center-stage while pushing everyone else into obscurity.Madrigal Martínez: (Spanish Translation) &quot;Don&#x27;t speak any Purépecha so you can speak Spanish.&quot; That&#x27;s what our teachers would say.Pérez: And as a result, those cultures become more difficult for historians to study.David Carballo: We don&#x27;t have the detail for Purépecha culture, that same level as, say, we do Mayans and the Aztecs.Pérez: On top of the relative anonymity...Madrigal Martínez: (Spanish Translation) Look at my uncle&#x27;s beautiful mask!Pérez: and the sparse study of these Indigenous communities...Madrigal Martínez: (Spanish Translation) He would dance a lot.Pérez: many of them pass down their ideas through symbols and unwritten traditions. The problem is, these can end up being misinterpreted by outsiders.Archival footage #1: Lake Patzcuaro is about 250 miles west of Mexico City.Pérez: More often than not...Archival footage #1:The island fishermen live in primitive adobe buildings centuries old.Pérez: people on the outside have failed to understand the complexity of these traditions, and how they might differ among multiple Indigenous cultures.Archival footage #1: Most primitive people all over the world stopped using the throwing stick when the bow and arrow was discovered. But here on this beautiful lake in Mexico, it is still used every day.Pérez: And it is from this outside and uninformed perspective that the misinformation about monarch butterflies might have originated.Archival footage #2: And so, these are the creations of the magic hands of Mexico.Carballo: I mean, I think it starts with tourism.Juárez: (Spanish Translation) These are the types of mistakes that are made in promoting tourism.Archival footage #2: These hands are not limited by age or gender. They know only one thing: how to create beauty.Carlos García Mora: (Spanish Translation) Often the people who create tourist information are not familiar with the regions they write about. And their touristic propaganda spreads misinformation.Archival footage #2: Centuries ago, the ancient Maya realized the mesmerizing power of silver.Carballo: A tourist-focused process, it doesn&#x27;t care so much about authenticity. It cares about just aggregating imagined realities of those people.Juárez: (Spanish Translation) The institutions in charge of promoting tourism take the elements as something they can sell, something that can be exploited.Archival footage #2: The magic hands of Mexico find beauty in everything. Most of all, in sharing that beauty with you.Juárez: (Spanish Translation) And that is what they have promoted. &quot;Come and see the spectacle.&quot;Madrigal Martínez: (Spanish Translation) Over here, look. My sister, the oldest. She is the one that passed away.Pérez: This is still happening today. Take the Day of the Dead, &quot;el Dia de los Muertos,&quot; as an example. Traditionally, it&#x27;s a day when family and friends gather to remember those who have died. But over time, it&#x27;s become a huge spectacle.And in 2016, Mexico City adopted a yearly Day of the Dead parade, copying a fictitious parade featured in the James Bond film &quot;Spectre&quot;. A completely new tradition created by the imagination of foreigners.Juárez: (Spanish Translation) This phenomenon of &quot;touristification&quot; is risky because it brings an economic activity that is more profitable than their own tradition, eroding their own cultural elements.Pérez: Which is why understanding, and ultimately respecting, unique traditions is so important.So let&#x27;s get the facts right. The Purépecha do use butterflies as a way to think about the afterlife. But not the monarchs. Theirs are butterflies that are small and white.Madrigal Martínez: (Spanish Translation) What I would play with when I was a little girl were little white butterflies. And that they would say was the soul of the children.Pérez: But it&#x27;s not just swapping monarchs for white butterflies. It is a completely different and more nuanced way of viewing the dead.Juárez: (Spanish Translation) The view the Purépecha have is that people die. But they also believe that their soul, their essence, keeps on living. But not like an abstract entity. But rather their presence can be felt within the fire, within the air...Pérez: or as butterflies.Juárez: (Spanish Translation) These butterflies flutter near where the kids play. The grandparents tell them not to scare them away because they are souls. But this is a communication, a very didactic way of familiarizing children with taking care of nature. For them to understand that souls can be understood this way, as subtle, but as present as though they were butterflies.Pérez: For the Purépecha, the dead remain constantly present, encountered in nature all around us. To explain this belief, the Purépecha turn to these small white butterflies and other natural phenomena.Now, misunderstandings aren&#x27;t exclusive to Mexico. Many would argue that lots of modern communities all around the world have their own misconceptions about Indigenous cultures. But that in itself just raises the question. How many more of these cultural misconceptions are out there and what can we do to prevent them?Carballo: By including indigenous voices today in understanding the deep history of the Americas, we get not only a more accurate understanding but one that reflects all of the diversity and the different perspectives of native peoples who&#x27;ve inhabited this hemisphere for thousands of years.Madrigal Martínez: (Spanish Translation) Without our customs, our community would be dead. We have many beautiful things in our little communities. Many, many beautiful things. It&#x27;s an honor being Purépecha.

The Big Lie about Monarch Butterflies Hero

Join NOVA producer Arlo Pérez as he unlearns a “fact” he was taught as a child.

The Big Lie about Monarch Butterflies

Image Credit: Gallinago_media, Shutterstock

In the past year, millions of the animals have been culled to stop the spread of COVID-19 on mink farms across Europe. But this is more than just a fur coat crisis.

What’s the deal with mink Covid?

Hear from two scientists trying to hack photosynthesis.
RUBISCO, which helps make photosynthesis happen, is the most plentiful enzyme on the planet. But it&#x27;s not the most efficient. Can a team of researchers give it a boost?
Meet the Enzyme Driving PhotosynthesisPublished: February 22, 2021David Pogue: Usually you hear about efficiency, like of a gas engine, measured in terms of percentage, how much fuel is ultimately converted to energy. What’s the percentage efficiency for a plant?Lisa Ainsworth: Well, in terms of how much of the light energy it turns into sugar, it’s pretty low maybe around three percent%.David Pogue: Three percent? That’s terrible. .Lisa Ainsworth: That’s the plan.David Pogue: To improve photosynthesis, two researchers, Amanda Cavanagh and Paul South, have focused on one of its key molecules. It has a very catchy name.Amanda Cavanagh: So the molecule is what we biologists call an enzyme. And so it does the work. Enzymes are like biological workers. And the enzyme’s called RUBISCO.Paul South: It’s RUBP, or ribulose bisphosphate carboxylase oxygenase.Amanda Cavanagh: And it’s, for most plant biologists, one of our favorite enzymes on the planet.Paul South: Yeah RUBISCO is our shortened term for it.David Pogue: Mainly because it’s fun to say.Amanda Cavanagh: Well it’s super fun to say.David Pogue: RUBISCO.Amanda Cavanagh: Of course. RUBISCO. But, it is also a really cool enzyme because it makes life on Earth possible.David Pogue: RUBISCO may not look so special but it is arguably the most important enzyme on the planet because of its critical role in photosynthesis. RUBISCO’s job is to grab a molecule of carbon dioxide and feed it into a molecular machine that’s building carbon chains. That means, any carbon atom, that’s part of any plant anywhere got there thanks to RUBISCO, or one of its close variants. And because we eat plants or animals that ate plants that also includes just about every carbon atom in your body—all approximately eight hundred, million, billion, billion of them. That’s 26 zeroes. Not bad RUBISCO, not bad.Paul South: Yeah so if it’s ever come from a plant, it had to have gone through that enzyme of RUBISCO.David Pogue: That’s wild. How come there’s not a memorial to RUBISCO in Washington? It seems like, sort of important.RUBISCO is important and that’s why it’s the most plentiful protein on Earth. But just because you’re important, doesn’t mean you’re entirely competent.Paul South: It’s, in this case, not the best enzyme in the world.Amanda Cavanagh: It’s got a hard job, so it’s doing its best, but at the same time it exists in an atmosphere that’s not predominantly carbon dioxide, it’s mostly oxygen.Paul South: And about one in every four or five reactions it grabs oxygen instead of carbon dioxide.David Pogue: That’s right. RUBISCO screws up about a fifth of the time. Instead of attaching a carbon dioxide, it attaches an oxygen molecule. And that’s trouble.You’re saying nature has created a screwed-up little worker enzyme?Paul South: Yeah so 400 million years ago, when this enzyme evolved, there wasn’t very much oxygen in the air.David Pogue: All right. So I’m the little RUBISCO enzyme and like on the conveyor belt here. And like carbon dioxide, carbon dioxide, carbon dioxide, carbon dioxide, oxygen and I- I don’t notice I accidentally grabbed oxygen out of the box.Paul South: And it produces compounds that are inhibitory to photosynthesis, so it kind of starts to shut things down.David Pogue: I mean it’s been going on for billions of years and nobody has cared.Amanda Cavanagh: Yeah, well..David Pogue: I mean, it all basically works.Amanda Cavanagh: Photosynthesis right now is sort of a victim of its own success, RUBISCO certainly is. So by oxygenating the atmosphere via photosynthesis, you now have a huge amount of oxygen in the atmosphere but you need a carbon dioxide to make the reaction work.David Pogue: So what happens when RUBISCO screws up? The result gets shipped out through a couple other parts of the cell to where the mess is taken apart and recycled, all of which consumes a lot of energy.So, if you could fix this inefficiency problem, the plant might make more soybeans, corn, whatever it is?Amanda Cavanagh: That’s exactly it. Then they will have that energy to put towards something that we will consider useful like making more food for us to eat.David Pogue: Is this just a crazy theory or is this some indication that this could actually work.Amanda Cavanagh: There is quite a bit of evidence that this is working. So right now, we have this tested in a couple of model species.David Pogue: It is tropical in here.Amanda and Paul take me to the greenhouse to see one example. Using two genes one from algae and the other from a pumpkin, they’ve modified tobacco plants to address RUBISCO’s “sloppy work.”And why are we using tobacco plants?Amanda Cavanagh: Yeah tobacco’s a really useful model crop for us.David Pogue: Why tobacco? Turns out it’s one of the easiest plants to genetically manipulate which makes it a common test subject.Paul South: They have definitely shown improvements in plant growth and total biomass, and we’ve been studying the rates of photosynthesis, and we are pretty confident now that our model crop is successful in this pathway, and now we’re really interested in moving these into something we like to eat.David Pogue: Reducing the energy penalty crops pay for RUBISCO’s mistakes could be huge. In soybeans, a 25% reduction could result in plants that produce more than 60 million more bushels a year.Amanda Cavanagh: This to a lot of people is an idea that might be out there, but if we can get it, if we can get this moonshot approach to work, then we’re going to have more food. And so that’s really what drives what I do.

Meet the Enzyme Driving Photosynthesis Hero

Hear from two scientists trying to hack photosynthesis.

Meet the Enzyme Driving Photosynthesis

A few months after competing in the 2008 Summer Olympics in Beijing, Norweigian horseback rider Tony André Hansen was stripped of his bronze medal. His horse Camiro had failed a drug test during the Games, testing positive for capsaicin. The International Equestrian Federation <a href="https://www.nytimes.com/2008/08/22/sports/olympics/22doping.html">dismissed the pair</a>, along with three other showjumping riders and horses, from the competition. Hansen has not competed in the show ring since.Capsaicin is the chemical responsible for the “heat” in chile peppers. Like many over-the-counter muscle rubs—think “IcyHot”—capsaicin can bring on both tingling sensitivity and numbness.
 

 
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 When applied as a <a href="https://www.reuters.com/article/us-olympics-equestrian-doping/norway-bronze-medalist-suspended-idUSPEK303420080821">paste or lotion to horses’ forelegs</a>, capsaicin can cause a burning sensation that would be exacerbated by knocking against the rails of a jump. If a showjumping horse lifts its legs higher, it avoids the potentially irritating touch of a fence—and its rider avoids incurring penalties. But capsaicin can also soothe aches and pains by temporarily <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6006555/">deactivating the nerve endings</a> where it’s applied. An exhausted horse with numbed nerves will perform better than an equally tired one that can feel the full pain of its aching muscles, according to the <a href="https://aaep.org/horsehealth/lameness-and-poor-performance-sport-horse-eventing">American Association of Equine Practitioners</a>, which is why capsaicin is banned from equestrian competitions to this day. “Capsaicin binds to the TRPV-1 receptor—a pain receptor present all over our bodies,” says Ivette Guzmán, a horticulturist and member of the Chile Pepper Institute of New Mexico State University. If a horse is sore, “applying capsaicin binds up those pain receptors,” she says. A horse may feel a little bit of heat from topical capsaicin, but “they won’t feel the pain,” Guzmán explains. “It works on us, too.”Just as horses experience a numbing feeling from a topical application of capsaicin, your tongue will tingle when you chew a hot pepper. This numbing sensation is often coupled with a burning one that’s enjoyed by spicy food-lovers around the world: Whether eating centuries-old cuisines like <a href="https://www.theatlantic.com/health/archive/2019/04/why-we-call-indian-dishes-curry-colonial-history/586828/">Indian curry</a> or saucy chicken wings on the popular YouTube series “Hot Ones,” human beings have subjected themselves to the uncomfortable chemistry of capsaicin <a href="http://sitn.hms.harvard.edu/flash/2012/issue131b/">for millennia</a>.<h3>The need for heat</h3>Pepper species native to the Americas fall within the genus Capsicum. Some Capsicum peppers, like the mild bell pepper, have no capsaicin at all. Others, like the jalapeño and habanero pepper—popular additions to dishes requiring some extra “heat”—do have the chemical. (A few Capsicum peppers, including the incredibly-hot ghost pepper, were developed in South Asia by hybridizing varieties from the Americas.)“A lot of people mistakenly think the seeds are what hold the spice,” Guzmán says. But “capsaicin is found in the part of the fruit called the placenta: the membrane that holds onto the seeds.”But spicy food doesn’t have to be hot to convey heat. In fact, capsaicin doesn’t physically burn your tongue and innards at all. When your body processes capsaicin, your nervous system sends out a response that activates your senses for touch and temperature. The same receptors responsible for blocking topical pain send signals to your brain that you’re being burned when you eat something spicy. And here’s the kick: Capsaicin alters the sensitivity of the pain receptors in your mouth, effectively lowering the temperature at which you feel burning pain. This is why jalapeño sauce feels burning hot even after being refrigerated.“These [receptors] work really well when they detect the correct stimulus,” says Joanna Buckley, a chemist at the University of Sheffield in England. “They respond to anything over 43 C (109 F). So if you have a hot cup of tea, this receptor will work correctly and tell you, ‘Oh, your tea’s a bit hot.’” The problem is, Buckley adds, these heat-sensing receptors are also triggered by a class of compounds called vanilloids. Capsaicin is one of them.
 

 
 

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 Chemically, capsaicin is corrosive (like hydrogen peroxide), acutely toxic (like chlorine), and irritating (like ammonia). And its irritant qualities won’t just fire up your mouth: Capsaicin can have a similar effect on other mucous membranes. If you’ve ever chopped peppers and then accidentally touched your eye, you understand how irritating this compound can be. So why do some people enjoy—and even get a thrill out of—eating a fruit with such a kick?“We get interviewed often by chiliheads,” Guzmán says. “I’m Mexican. I grew up eating jalapeños, I grew up eating really spicy food, and I understand that there are other chemicals in [peppers] that are medicinal. But when it comes to chiliheads, I think they’re fascinated by the chemistry of capsaicin and how it makes you feel something you’ve never felt before. It gives you a euphoria.” Measuring that euphoria depends on the Scoville scale.<h3>Let’s talk Scovilles</h3>Named for American pharmacist Wilbur Scoville, <a href="https://www.vox.com/2016/1/22/10810564/wilbur-scoville-google-doodle">the Scoville scale</a> ranks the pungency of chile peppers based on the concentration of capsaicin in the pepper. It’s this concentration that determines how our bodies will react to peppers; while small amounts of capsaicin fall within the “spicy chicken dinner” category, stronger concentrations spell out “weapon-grade pepper spray.” In the early 1900s, Scoville, who was working as a chemist at the time, attempted to test out people’s relative capsaicin tolerance. He recruited five human subjects to taste-test mixtures of dried pepper and sugar water and had them report how hot they found each mixture to be. The basis of his heat scale is the amount of sugar water needed to dilute the mixture enough for the majority of his subjects to no longer feel the heat. These days, a technique called high-performance liquid chromatography is used to determine exactly how much capsaicin a pepper contains in parts per million, and multiplying the result by 16 converts it to <a href="https://www.smithsonianmag.com/arts-culture/how-hot-is-that-pepper-how-scientists-measure-spiciness-884380/">Scoville Heat Units (SHUs)</a>.
 

 
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 The highest level of naturally occuring capsaicin is in the Carolina Reaper, the hottest pepper in the world. Its creator, chile pepper grower Ed Currie, bred the pepper by taking one uniquely spicy <a href="https://www.palmettobluff.com/discover/fear-the-reaper">habanero</a> grown on the La Soufrière volcano on Saint Vincent in the Caribbean and crossing it with a Naga Viper pepper, which was developed in the United Kingdom from peppers hailing from the Caribbean and South Asia. The hottest single Carolina Reaper ever to be harvested rang in at 2.2 million SHU, meaning that more than a tenth of the pepper was pure capsaicin.High amounts of capsaicin, like those found in the Carolina Reaper, can cause injury. “Capsaicin is a really potent chemical. If you have too much of it, it can be toxic,” Buckley says. “It’s the thing that’s used in pepper spray. We’ve all seen images of people who have been pepper sprayed. Their eyes are swollen up, they’re crying, they can’t see…so it’s incredibly important to know how to handle capsaicin” safely, she says.<h3>Your body’s battle against spice</h3>If you don’t welcome spicy burns, there’s a way to neutralize the compound’s effects: dairy. “Capsaicin is an oil and it is insoluble in cold water,” Buckley says. Though it’s somewhat soluble in alcohol, like beer, Buckley explains, capsaicin is best dissolved by another oil. “You need to find something that’s fatty to dissolve the capsaicin,” she says. “That’s why the best thing to drink is milk.” Although spicy food is sometimes associated with stomach problems—Currie, who not only created the Carolina Reaper but also eats one every day, still <a href="https://www.latimes.com/nation/la-na-reaper-pepper-20141127-story.html#">experiences severe stomach cramps</a>—there is no direct evidence that spicy food causes belly cramps or nausea. The perceived pain, Guzmán explains, may just be a side effect of your gut membranes being irritated. While a 2016 study showed capsaicin can cause those with abdominal disorders to experience <a href="https://pubmed.ncbi.nlm.nih.gov/27094759/">flare-ups in their symptoms,</a> the same can be said for <a href="https://www.pbs.org/wgbh/nova/article/unless-you-have-celiac-disease-gluten-sensitivity-is-probably-just-in-your-head/">too much bread</a>, a famously unspicy food.But there are always worst-case scenarios.
 <figure class="richtext-image full-width"><img alt="Trinidad scorpion pepper" class="richtext-image full-width" height="450" width="800"
 src="https://www.pbs.org/wgbh/nova/media/images/Trinidad_Scorpion_Pepper.width-800.jpg"/><figcaption>A Trinidad moruga scorpion pepper, which is currently the second hottest pepper in the world to the Carolina reaper. Image credit: John Vonderlin, Flickr<div class="credit"></div></figcaption>
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 More than 150 different varieties of chile grow in a garden at New Mexico State University’s Chile Pepper Institute. “One year we had a group of students we were doing a tour with in the garden. And one student thought it would be funny if he bit a tiny piece off a Trinidad Scorpion pepper,” Guzmán says. “He did that, and he threw up in the garden, and he passed out, and we had to carry him to a shaded area under some trees.” Because capsaicin is a toxin, Guzmán explains, the human body’s first response to an excess of it is to flush it out. (In the student’s case, by vomiting.) In 2018, the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5893965/">National Institutes of Health reported</a> that a previously healthy 34-year-old man was admitted to the hospital with “thunderclap headaches”—sudden, severe head pain accompanied by fever, blurred vision, and even seizures—after eating a Carolina Reaper whole. Doctors treated him by flushing the capsaicin out of his body, which, like many chemical compounds in large amounts, can be dangerous. Of course, Olympic equestrian Tony André Hansen’s story shows that even a small amount of this complex compound can be damaging (and in some cases, even career-ruining). It just depends on where—or upon whom—the capsaicin ends up.
 

 
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Red hot chili peppers, and other hot peppers within the Capsicum genus, get their heat from the chemical capsaicin. Image credit: Austin Kirk, Flickr

Discover capsaicin, the active ingredient in chile peppers. (If you can take the heat.)

From jumping horses to jalapeños: the science of spicy peppers

What’s in this snail’s paralyzing venom?
Scientists explore how the powerful peptides found in marine cone snail venom can be used for medicinal and therapeutic purposes.
How Killer Snail Venom Plays a Key Role in Drug DevelopmentPublished: February 11, 2021David Pogue: Time to meet my first Professor of Venoms, Mandë Holford, of Hunter College. Now, I couldn’t help noticing, there’s a huge, terrifying tarantula on me. Is she poisonous?Mandë Holford: No, no, she’s not poisonous.Pogue: Oh, whew!Holford: She is, however, venomous and could still be lethal.Pogue: Thanks for bringing that up. Poisonous and venomous don’t mean the same thing?Holford: No, no, no, not at all.Pogue: Poisonous versus venomous: it all comes down to the delivery system. If you bite it and get sick, it’s poisonous, but if it bites you and you get sick, it’s venomous. In general, the source of their toxins is different, as well.This poison dart frog becomes poisonous from its diet. If raised in captivity, on different foods, it can become non-toxic, whereas this rattlesnake generates its own venom. It’s built into its D.N.A. So, snakes, scorpions, spiders: which fearsome creature is the focus of Mandë’s work?Killer snails? Is it accurate to say that you study killer snails?Holford: Killer snails are actually my affectionate term for venomous marine snails. And so, these are snails that live in the sea, and they have a venom, like snakes or scorpions or spiders, and the venom can be very lethal to humans.Pogue: It’s true that the snail can kill you, but usually it’s just looking for dinner, a worm or a fish.So, I’m a fish. What happens to me?Holford: Well, what happens is this guy will smell that you’re in the water, right? He puts out something called a siphon, and it’s a chemosensory organ, smells that, “Hmm, tasty meal in the water,” then it sticks out something like a tongue. It’s called a “false” tongue, “proboscis.” And, on the tip of the tongue, it has a little tooth, filled with venom that then will get injected into the fish. The fish instantly will become paralyzed, depending on what cocktail of venom gets injected into it. The snail will then open its mouth really wide, swallow the fish whole and have a really nice, tasty meal.Pogue: The whole thing sounds so improbable.Holford: I love it. Just when you think you’ve heard of everything, nature will surprise you with something new.Pogue: So, what’s in that paralyzing venom? To find out, Mandë and her team collect specimens from around the world. Back at the lab, they analyze tissue samples from the snail’s muscular foot and its venom gland.Juliette Gorson: So, we’re eventually going to look at the D.N.A., so we can make a species identification. That, we can use the foot tissue for. And then the venom gland tissue we can use to look for the individual venom toxins within the venom duct.Pogue: Turns out, the cone snail’s venom isn’t one thing but a cocktail of as many as 250 short “mini” proteins, also called peptides.Holford: So, if you think of venom, think of it not as like a single bullet, right? It’s more like, I like to describe it as a cluster bomb. It’s a series of bullets coming at you, and each individual bullet has a target in the physiological system.Pogue: Each venom peptide has evolved to mount a very specific attack, often acting as keys that fit a cell’s lock-like receptors. In the case of the nervous system, that can prevent a specific neuron from transmitting an impulse or, conversely, jam the neuron open, generating a flood of signals.In the wild, all those targeted attacks paralyze the snail’s prey, but the precision with which the venom peptides act also means that they may have another role as medicines.Holford: And so, we study these venoms to try to figure out novel medicines for treating things in pain and cancer. Actually, they make great drugs because they’re highly specific, very fast-acting and very potent.Pogue: A venom curing instead of killing? Wouldn’t be the first time.There are currently at least seven drugs on the market developed out of the study of venoms. They include an anticoagulant derived from medicinal leeches and a diabetes medicine from Gila monsters. There’s even one already from cone snails, an analgesic to treat severe chronic pain.Holford: And it’s the exact peptide that you would find in the venom. It’s not a derivative of it, it’s not a small molecule, it’s exactly as nature expressed it in the animal.Gorson: And I’ll just run a simple D.N.A. extraction.Pogue: Mandë’s team has already made some major breakthroughs.Tanya Napolitano: So, I could do a nano-LC-MS and see what’s inside of here.Pogue: In 2014, they identified a peptide from another venomous snail that attacks liver tumor cells, inhibiting their growth. It’s cutting-edge work that’s reaping the rewards to be found at the intersection of chemistry and biology.Holford: Learning how the venom is used more in ecological settings helps to further us in terms of how we understand how it can be applied for medicinal or therapeutic applications. And so, right now, it’s a fun time to be a venom scientist, because those worlds are colliding.

How Killer Snail Venom Plays a Key Role in Drug Development Hero

What’s in this snail’s paralyzing venom?

How Killer Snail Venom Plays a Key Role in Drug Development

Lions and African wild dogs hunt their prey very differently.
Gorongosa National Park&#x27;s top feline predator—the lion—hunts by ambush. Discover how gregarious wild dogs use an entirely different strategy to take down prey.
The Anatomy of an African Wild Dog HuntPublished: January 26, 2021Narrator: In an African wilderness like Mozambique&#x27;s Gorongosa National Park, each animal faces a fundamental task—day in, day out—finding something to eat. Herbivores have an additional challenge: they must also avoid being eaten. As for carnivores, to survive, they must kill. And to kill, they must hunt. Paola Bouley: There&#x27;s some dance that happens between those two groups of species. One doesn&#x27;t want to be eaten, the other needs to eat. So, they each fulfill a unique niche in the ecology of the system.Narrator: Two top carnivore species roam the forests and floodplains of Gorongosa: African wild dogs and lions. Each has their own particular style of hunting, and their own unique effect on the prey species around them. Bouley: A lion is an ambush predator and our lions in Gorongosa tend to hang out in the tall grass and they almost literally wait for something to walk into their mouths. They’re not out running on the flood plains chasing down prey. They don’t have to spend that energy. There’s a stray waterbuck or a warthog that’s just walking through the grass… and all of a sudden, a lion is there. And it takes a split second for a lion to take it down.Narrator: Prey are so plentiful in Gorongosa, lion rarely roam from their favorite grasslands, limiting their impact on the ecosystem. Wide-ranging wild dogs provide an essential contrast. Bouley: Compared to an ambush predator like a lion, a wild dog is a coursing predator. And that means that it chases down its prey. It’s not sitting, lying in wait for something to walk up to its area. It’s going to chase down what it wants to consume.Narrator: Weighing less than eighty pounds, African wild dogs are built for speed and endurance. Their long, thin legs can carry them over a mile during a hunt and propel them at speeds approaching 40 miles an hour. Bouley: Now, a lion is going to think twice about running after something, especially if they can just pick it out of the grass. But dogs are not stealthy in that sense. They’re gregarious. They’re playing together. They’re noisy. Animals see them coming from far. They’re not stealthy at all. So, they have to rely on the chasing. Chasing, clearing, very different strategy to a lion.Narrator: And there&#x27;s much more to that strategy than simply out-running prey. The pack&#x27;s meals emerge from an extraordinary routine. Bouley: A typical day for the dogs right now is they tend to rest during the heat of the day but in the early mornings and late afternoons they begin to play, socialize more together and they hunt. António &quot;Tonecas&quot; Paulo: (Translated from Portuguese) About thirty minutes before the hunt, they start playing, and you can see at that stage that they start to lower their heads and prick up their ears a bit and they make a calling sound between them.Bouley: So, we&#x27;re looking at some of the best wild dog habit here. It&#x27;s a wide-open expanse, really flat, hard substrate—and they&#x27;ll course through here.They start moving across the landscape and then fractions of the pack break off and begin to select prey. Those dogs out in front who want to start hunting are out there already sussing everyone out.Here we go.Here in Gorongosa, we have palm thickets, and termite mounds and little patches of forest. Animals like a bushbuck or an oribi would be hunkered in the shade and what we have is a pack of dogs and a wave of teeth that are just sweeping through the landscape, sifting animals out of their refuges, and looking for that one weak moment.Narrator: Once a victim is flushed out, the wild dogs kick into high gear. Paulo: (Translated from Portuguese) They chase their prey at a very high speed. When this wave arrives, the prey has little chance to survive the attack.Bouley: The beauty of a pack is that they function as a whole. Everybody needs to do well together. The sum is greater than the parts with a wild dog pack. There&#x27;s no fighting at kills. There&#x27;s no outward aggression like you&#x27;ll see with the lion. Everybody gets to eat, nothing is wasted. So, vultures will hang around, but there&#x27;s very little scraps to be taken. They consume everything.So, they’re having an impact on how animals are distributing themselves because herbivores understand: that’s a predator. They are fulfilling a unique role as a coursing predator in this system. And that’s a good thing.

The Anatomy of an African Wild Dog Hunt Hero

Lions and African wild dogs hunt their prey very differently.

The Anatomy of an African Wild Dog Hunt

Gorongosa National Park in Mozambique was once one of the most species-rich places in Africa.
By protecting lions from traps and snares, veterinarians, park rangers, and ecologists are working together to restore this feline&#x27;s population in Gorongosa National Park.
Lions Return to Mozambique&#x27;s Gorongosa National ParkPublished: November 2, 2020Onscreen: Gorongosa National Park in Mozambique was once one of the most species-rich places in Africa. But like the rest of the country, the park was decimated by a long and bloody war.Antonio &quot;Tonecas&quot; Paulo: (Translated from Portuguese) The war brought misery and unemployment. Many people died of hunger, because they were unable to grow crops. They were always on the move trying to escape the fighting.Paola Bouley: Armies had to eat, elephants were killed, tusks were sold to buy guns. So, everything just pretty much got wiped out.Onscreen: After the fighting ended, some herbivore species quickly rebounded. But the only top predators to survive were a handful of lions. By the time Paola Bouley arrived in 2012, the war had been over nearly 20 years. Bouley: When I got here, nothing was known about lions. There had never been any formal research on carnivores. So, people had, you know, casual observations about how many lions and where, but we really had no data.I thought I saw something back there.The first thing you want to do is count. You want to know how many and where.Where is everybody?But we had a hell of a time in the beginning, actually finding lions in this wilderness. It&#x27;s mostly roadless, it&#x27;s long-grass habitats, so we worked in the beginning just to be able to see lions.He’s a beautiful lion…And then, we took it a step further and began to put GPS collars on prides and coalitions – so, groups of females, groups of males – and those, in turn, took us deeper into the story. And what we quickly found is that lions were still being killed.People were setting wire snares in the landscape to catch warthogs and waterbuck and buffalo, but they were also, they were catching lions. Lions are by-catch in those traps.Jinga lost his foot in a gin trap in February.And the numbers were showing 1 in 3 were either maimed – like losing actual limbs – or killed in these snares. I came here as an ecologist, as a scientist…Start the timer....but quickly had to switch gears, because when we saw the trends for lions here and other species we had to intervene.That was the leap that we made as a team. We went from being scientists – purely scientists just collecting data – to intervening and really trying to get the population jumpstarted.So, we’ll collar him so we can monitor his progress and keep treating him.So, we had to stop the illegal hunting. We had to create a refuge for these species to naturally recover.Paulo: (Translated from Portuguese) When I started working here, the situation with traps was traumatic. It was a very serious problem. The area was full of traps and snares. That’s when we started training our rangers to clean up and remove wire snares and traps from places where the lions roamed.Bouley: The rangers are the ones on the ground, and we put technology in their hands – high resolution satellite imagery – and we paired their patrols with GPS data we were getting from the collars. So, those satellite collars at our lions send us positions every few hours, so we know where lions are, we know where the core habitats are, and so we know where to focus strategic patrols. In the first two years we saw a complete turnaround in the situation. Lion poaching declined by 95%. We haven&#x27;t had a lion snared in over a year already and believe me, I look.Paulo: (Translated from Portuguese) Now, it is possible to go through a whole year without any animals getting caught in a trap. And for us that’s a fantastic result. Now, we have to preserve what we have.Onscreen: The current estimated Gorongosa lion population is around 150. Bouley: In the past three years, we&#x27;ve had 13 cubs and seven of those have been female. And that&#x27;s the beauty of lions. If you give them the opportunity, they grow. They breed almost every two years, the survival is very high in Gorongosa, there&#x27;s a lot of food, there&#x27;s a lot of space. So, they&#x27;ve done very well. We understand from the science and the data that we’ve collected that we could have three times as many lions in this park than we currently have and so that’s a target. That’s a goal. And so, we use the science and the data to really guide us towards those. What we&#x27;re trying to do here is heal the ecosystem. Put the pieces back together.Onscreen: In 2017, Gorongosa was considered safe enough to reintroduce African wild dogs to the park. Bouley: Lions took us straight to the heart of a problem, and once we solved their problem, it laid the ground for all these other species to come back too. It really was just a matter of letting nature do what it does best, and we did that by just taking the human factor out of the situation. So, where before humans were having a negative impact on populations – by setting snares, by shooting animals – you remove that, and you just step back and you let nature take its course. And in a system as robust and resilient as Gorongosa, you can let that happen.

Lions Return to Mozambique's Gorongosa National Park Hero

Gorongosa National Park in Mozambique was once one of the most species-rich places in Africa.

Topic: Nature

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