Learn why periodical cicadas come out every 13 or 17 years; why people with high cognitive abilities tend to choke under pressure; and how DNA analysis could solve the mystery of the Dead Sea Scrolls.
Learn why periodical cicadas come out every 13 or 17 years; why people with high cognitive abilities tend to choke under pressure; and how DNA analysis could solve the mystery of the Dead Sea Scrolls.
Why periodical cicadas come out every 13 or 17 years by Cameron Duke
People with high cognitive ability tend to choke under pressure by Kelsey Donk
The mystery of the Dead Sea Scrolls might be solved with DNA analysis by Grant Currin
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Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/periodical-cicadas-101-why-smarter-people-choke-under-pressure-and-analyzing-dna-to-solve-the-dead-sea-scrolls-mystery
CODY: Hi! You’re about to get smarter in just a few minutes with Curiosity Daily from curiosity-dot-com. I’m Cody Gough.
ASHLEY: And I’m Ashley Hamer. Today, you’ll learn why periodical cicadas come out every 13 or 17 years; why people with high cognitive abilities tend to choke under pressure; and how DNA analysis could solve the mystery of the Dead Sea Scrolls.
CODY: Let’s satisfy some curiosity.
Shhhh...do you hear that rhythmic buzzing? For many parts of the United States, that’s the sound of summer. It’s the sound of cicadas.
CODY: Yes, I’ve noticed it, and I haven’t had to be quiet to do it. They were DEAFENING [ad lib about cicadas]
ASHLEY: This summer, billions of these buzzy bugs are scheduled to emerge in the eastern half of the US, seemingly out of nowhere. But why do they all come out at once? Turns out it’s a survival strategy — one of the strangest survival strategies in the animal kingdom.
Here’s the deal with cicadas. They spend most of their lives underground feeding on plant roots. They’d probably be perfectly content to do that their whole lives if it wasn’t for one tiny problem: living alone in a hole underground makes it tough to find a mate. [Boy, do I KNOW.] So once the soil reaches the right temperature, all of these loners come out of the ground at once. According to one Virginia Tech researcher, their emergence can be as dense as 1.5 million insects per acre. The grand finale of their quiet existence is a metamorphosis to an adult stage, when their all-white exoskeleton hardens and darkens to a sleek black, brown, or green.
There are more than 3,000 species of cicada, and most emerge every year in late June through August. Only seven species are what you call periodical cicadas, which only emerge every 13 or 17 years. These cicada species each live in geographically distinct broods, each of which emerges at its own specific interval. This year, it’s Brood 9’s turn: a group of periodical cicadas that have been biding their time beneath southwestern Virginia, southern West Virginia, and the tip of North Carolina for 17 long years. Such a lengthy lifespan isn’t just weird for cicadas, it’s weird for insects in general. Scientists don’t know of any other insect that takes this long to reach adulthood.
Once they emerge above ground, they have one goal: Survive just long enough to mate. That’s no simple feat; cicadas are easy targets for birds and other predators. They’re loud enough to cause hearing damage, they don’t bite, and they aren’t poisonous. So how do they defend themselves?
Well... they don’t. And that’s the point. They don’t really need to. They actually double down on being helpless and tasty to survive.
This is called the predator satiation strategy, and it is one of the strangest anti-predator adaptations there is. They emerge in such great numbers infrequently enough and with good enough timing that predators can eat as many as they want and they still won’t dent the cicada population. It’s weird, but it works.
The smarter a person is, the better they’ll be at their job, right? That’s what a lot of hiring managers think, and it’s why sometimes you have to take a test as part of a job application. But new research shows that’s not necessarily true. Instead, people with high cognitive abilities might be more likely to break when the pressure is on.
To come to this conclusion, Iowa State University management professor Dr. Mike Howe looked at a measure of intelligence called general mental ability, or GMA. That’s a measure that many companies use to judge how well a potential hire will perform. Generally, the higher your GMA, the better you are at learning, understanding, and solving problems.
Dr. Howe found that this isn't always true. If the rules of the task are always changing or if there's a lot of pressure to succeed, people with high GMA tend to choke under pressure. In those conditions, people with high GMA end up performing at the same level as people with low GMA.
Here’s why this happens: when people with high GMA are put under pressure, the stress consumes a lot of their mental resources — the same super-sized mental resources they rely on to perform better than people with low GMA. As a result, they’re left using less effective strategies, which brings their performance right in line with everybody else. It’s like if they had the best car in a race but got a flat tire at the start line.
The good news? The study found a fix: if the high-GMA person thinks about the task as a learning exercise or if they strive to "just do their best," it takes the pressure off and they perform a whole lot better.
To figure that out, Dr. Howe recruited 261 college students studying business. They took a test to measure their GMA, and then they did a stock-market task. Some of them were told they’d be judged on their performance, some were told to practice developing the best system, and others were told to do their best.
Next, the tasks were made less predictable to mimic how things might happen in the real world. And the high-GMA people who were being judged on their performance? Totally choked. But the high-GMA people in the do-your-best condition adapted really well.
The important takeaway here: to paraphrase Dune, pressure is the mind-killer. Whatever you can do to remove or reframe that pressure will help you in the long run. So focus on doing your best! That’s all anyone can do, after all.
The Dead Sea Scrolls are the ultimate jigsaw puzzle. These ancient Jewish texts were one of the most important discoveries in the history of archaeology, but they were found in thousands of tiny fragments that experts have struggled to put together. That’s why it’s big news that researchers have turned to a new source of evidence to help piece these fragments together: DNA.
The Dead Sea scrolls were written on animal skins about 2,000 years ago, and their first discovery happened accidentally when Bedouin [BED-uh-win] teenagers stumbled on the cave they were stored in in the late 1940s. We now know that the whole corpus contains nearly a thousand manuscripts, including the earliest known versions of some books of the Hebrew Bible. Unfortunately, the years weren’t kind to the animal skins the texts were written on, and they’re now reduced to some 25,000 fragments. And those fragments weren’t always kept together: many of the scrolls were acquired and sold by antiquities dealers, so researchers have to guess which pieces go where. They’ve spent decades carefully re-assembling the documents by relying on visible clues, like color and edge shapes. Like I said, it’s the ultimate jigsaw puzzle.
That’s where the DNA comes in. Researchers focusing on scrolls traced to Qumran [kum-RON] in the West Bank have extracted a lot of useful information from genetic material taken from the fragments themselves.
One of the most helpful clues they turned up was actually pretty simple. Remember, these texts were written on animal hide, and animals have DNA. The team was able to use that DNA to determine the species of animal that a particular fragment came from. It turns out that most of the scrolls were written on sheepskin, but others were written on hides from cows and goats. That information helped them determine that some fragments they thought were written near Qumran probably weren’t. Those fragments were cowhide, which probably wasn’t super available in the Judean desert.
But that’s not all. The DNA evidence also let the researchers identify which fragments came from the same sheep and even which ones came from closely related animals.
There’s still a lot of work to be done, but that kind of information will make it a lot easier to determine which fragments belong to the same manuscript or at least whether they came from similar locations. It’ll get us a lot closer to finishing this ancient jigsaw puzzle once and for all.
Let’s recap what we learned today to wrap up. Starting with
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CODY: Today’s stories were written by Cameron Duke, Kelsey Donk, and Grant Currin, and edited by Ashley Hamer, who’s the managing editor for Curiosity Daily.
ASHLEY: Today’s episode was produced and edited by Cody Gough.
CODY: Join us again tomorrow to learn something new in just a few minutes.
ASHLEY: And until then, stay curious!