Earth's Ultimate Survivors

Joe: Hey, smart people! Joe here. Animals are great. So smart, so weird. I love 'em. I mean, I am one. But some of them have some explaining to do. Like scorpions. They just look like they're built to fight. Angry in the front, angry in the back. So aggressive! Seems a little over the top if you ask me. But maybe they're just misunderstood. I am willing to change my mind. So let's go to California and meet a scorpion biologist.

(record scratching) Yes, there are people who hang out with them voluntarily. Maybe instead of scaring us to death, scorpions might actually be able to save our lives? (playful mysterious music)

(quiet playful music)

[Lauren] I'm Lauren Esposito and I'm the curator of arachnology, which means that I study spiders and scorpions.

Joe: I'm friends with one of those things. Maybe I'll be friends with both of 'em by the time we walk out of here. My first question is, can they in fact rock you like a hurricane? ("Rock You Like A Hurricane") ♪ Rock you like a hurricane ♪

Lauren: Yeah, I mean, most definitely. At least in the case of scorpions, they can definitely rock you like a hurricane, because they can sting and it really hurts.

Joe: They are not subtle at all. Like, they're delivering a very aggressive energy with their entire body. Every time you look at them it's just pokey, kind of angry.

Lauren: I mean, is it, though? I feel like you're looking at it through the wrong lens.

Joe: You need to help me view this through a different lens. I'm not sure I am. These guys have been wreaking havoc since prehistoric times. They've been around for 450 million years. I mean, that's longer than trees. And 450 million years ago, there weren't even animals on land yet. You know what scorpions were doing? They were terrorizing anything edible living in the water.

Lauren: Most things were living in the ocean in, like, sort of early eras of life on Earth, and scorpions were no different. Their ancestors were these things called eurypterids, or sea scorpions, and they were huge.

Joe: How big are we talking?

Lauren: I mean, in the case of the marine ancestors, we're talking like five meters, like really big, big animals, like massive.

Joe: Did they have to be that big? That's a little too big.

Lauren: Did they? I mean, I don't know. I feel like that was unnecessary, but I guess, like, evolution did some really crazy things back then, and there was all kinds of weird experiments.

Joe: Just trying all kinds of weird stuff.

Lauren: Yeah, like crazy experiments. So they left the ocean, became amphibious. So they were both using the ocean for part of their life, but also coming up on the land for part of their life. And some of the earliest evidence we have for that is there's these trackways, so scorpion footprints alongside ancient riverbeds. So they left their tracks in the mud of these rivers, and they were coming up on land to hunt spawning fish. So they were sort of like the version of grizzlies today eating the ancestors of salmon back then, so kind of doing what grizzlies do.

Joe: Thankfully, evolution took scorpions down a notch. 450 million years later, most scorpions can now fit in the palm of your hand. Not that I recommend necessarily doing that. (cat screeching) (glass smashing) (cheerful jazzy music) Which I definitely prefer over a scorpion half the length of a school bus. (school kids screaming) But the crazy thing is that scorpions' basic body plan really hasn't changed. They still look like bizarro lobsters with claws up front, stinger in the back. They even still breathe the same way they did back when they lived in water. They use these organs called book lungs that are essentially gills, they've just moved inside the body. And it turns out this is a pretty solid body plan, because scorpions just keep existing. 443 million years ago, they survived a mass extinction that wiped out around 85% of life on Earth. Then they rode out multiple ice ages, new predators, and that asteroid that killed the dinosaurs. Nothing phases them. And now there are nearly 3,000 scorpion species on Earth and counting. And not just in the desert. They live in tropical rainforests, savannas, the Himalayas, basically every part of Earth that's not frozen for most of the year.

Lauren: So they've been really, really successful both in terms of, like, long-scale, deep evolutionary time, but also in terms of where they live on the world, because they live basically everywhere. And so if you wanna know about ecology and evolution, scorpions are a pretty good place to start.

Joe: And so, like, what we do as scorpion scientists is we go out at night, usually on a moonless night, because that's when scorpion activity is the highest. Their activity is reversely correlated with the moon.

Lauren: Because the moon's just a sun mirror, so they're just like- - It's a sun mirror, and they, like, don't want to be seen, 'cause they want to be, like, secretive and hunting like stealthy predators, and also mostly not getting eaten is the main thing. So they come out on moonless nights and they're usually just out in their habitat doing their scorpion things, like looking for mates, looking for food, hanging out, drinking water, you know, whatever.

Joe: It's actually easier than it sounds to look for scorpions on a moonless night because they have these fluorescent compounds in their exoskeletons and they glow under UV light. No one's quite sure why. It might be because seeing their own glow tells them when they're out exposed and they can get into hiding. - Run!

Lauren: But scientists still really haven't figured this out. Either way, it's how scientists like Lauren can easily find them.

Joe: And yeah, you just kinda, like, stumble around looking with the blacklight. And when you spot a scorpion, it's usually from pretty far away because they fluoresce really bright and it looks like toxic sludge green.

Joe: It's just like a totally unnatural color in the environment. - Yeah, totally unnatural.

Joe: It's like, bingo! So after Lauren catches a scorpion, she sticks it in a container and takes it back to the lab. Now, chances are if you know one thing about scorpions it's that they have a giant tail full of venom. But the vast majority of scorpions are not gonna kill a human. Like, what would they even do with you, like eat you? Come on. But they will hurt you.

Lauren: Does a super good job, yeah. It feels like, you know, getting stung by scorpion, it's like the tiniest of pricks