To celebrate Shark Week, learn about why people are afraid of sharks; how scientists discovered four new species of “walking” sharks (also called epaulette sharks); and how enhanced rock weathering might help us fight climate change with rocks.
To celebrate Shark Week, learn about why people are afraid of sharks; how scientists discovered four new species of “walking” sharks (also called epaulette sharks); and how enhanced rock weathering might help us fight climate change with rocks.
People are afraid of sharks for 3 psychological reasons by Kelsey Donk
Four new species of "walking" sharks were discovered this year by Grant Currin
We may be able to fight climate change with rocks by Cameron Duke
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Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/why-people-are-afraid-of-sharks-discovery-of-4-walking-shark-species-and-fighting-climate-change-with-rocks
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. And it’s SHARK WEEK!
[OPTION: Where’s our Shark Week music?? [cue music] That’s better!]
Today, you’ll learn about why people are afraid of sharks; how scientists discovered four new species of “walking” sharks; and how we might be able to fight climate change with rocks.
CODY: Let’s satisfy some curiosity.
You probably know that shark attacks are rare. You have a greater chance of being struck dead by lightning than being killed by a shark. Sure, fine. But even though we know the odds, the majority of people still admit to a fear of sharks. Why? Well, it’s not irrational. People are afraid of sharks for three big psychological reasons, and they all have to do with the way our brains perceive risk.
Reason number one: We worry more about risks that involve a lot of pain and suffering.
Basically, even though you’re way more likely to die of a heart attack than a shark attack, the idea of being torn limb from limb by a shark is terrifying. Heart attacks seem a lot less painful in comparison.
Reason number two: We worry more about risks that involve uncertainty. Swimming in dark, murky water where anything could be lurking beneath you is scary. Plus, sharks are unfamiliar — most of us don’t know much about what makes a shark attack or how to protect ourselves if it does.
And reason number three: We worry more about the risks that easily come to mind — something experts call availability bias. When the media covers shark attacks, they’re top-of-mind and we worry about them more. It’s hard to sell newspapers with a headline like “Local man diagnosed with skin cancer.”
As reasonable as those fears are, though, the fact remains that shark attacks are super unlikely. So how can we fight those fears?
Well, the first step is remembering the weird ways your brain assesses risk. When you feel yourself getting nervous about a shark attack, remind yourself why you’re afraid. The death seems grisly, the uncertainty is hard to cope with, and we’ve seen shark attacks in the news.
Then, take steps to reduce some of these factors. You can reduce your uncertainty by giving yourself a sense of control: swim in clear water where you can see the bottom. Research which shark species live where you’ll be swimming, since there’s a good chance they’ve never attacked humans.
And just to be on the safe side, brush up on what to do if you are attacked. Hint: do not punch it in the nose. Instead, try to put a solid object between you and the shark, and as a last resort, claw at its eyes and gills.
But it’s worth repeating that shark attacks are very, very rare. Give yourself a little more control, and just enjoy your swim. And hey, sharks could be a lot MORE scary — it’s not like they can walk on land, right?
Researchers working in the Pacific have discovered four new species of sharks with a special skill you won’t believe: they use their fins to walk. And when the tide goes low, these sharks go high, sometimes walking on top of coral reefs above the water. [CODY: NOOOOOO] But there’s nothing for humans to worry about. These sharks only grow to about three feet (that’s one meter) and they basically just prey on small fish and invertebrates. [CODY: Phew]
Scientists found these four new species as part of a 12-year investigation into the evolutionary history of walking sharks, also called epaulette sharks [EP-uh-let]. Nine species in total have been identified, and scientists are trying to figure out how these unusual creatures came to exist.
Sharks have been around for a very, very long time. About 400 million years, to be exact. To put that in context, the oldest dinosaur fossil ever found was only two-hundred-forty million years old. But despite having all that time for evolution, sharks don’t seem to have done all that much evolving. Scientists have only found evidence that about 1200 species of sharks and rays have ever existed. Fossilized teeth from sharks living one-hundred-eighty million years ago are about the same as the teeth the same species have today.
One exception to that trend is — you guessed it — the epaulette shark. One reason for this probably has to do with their native region. The coral reef ecosystems of New Guinea and Northern Australia are changing all the time. Sea levels rise and fall, currents are constantly shifting, and the reefs themselves rise and die. These factors reward fast evolution, which leads to diversity.
The researchers analyzed the sharks’ DNA for clues about their evolutionary history. It turns out this group of sharks split off about nine million years ago. The researchers think that rising sea levels and cooler ocean temperatures forced the sharks’ ancestors to migrate to warmer waters. They also think some of the sharks took a very slow ride on a tectonic plate as it drifted all the way from the Australian coast to New Guinea. When the plate settled, it cut these sharks off from each other — and that may be why they turned into so many separate species.
It’s hard to say what the future holds for these sharks because we know so little about them. Are they threatened? Endangered? Scientists need to do more research before they can say for sure.
But fish that can walk? Ariel would be so jealous.
If we’re going to fight climate change, emitting less CO2 may not be enough. We may also have to start taking CO2 out of the atmosphere. But that doesn’t necessarily mean using giant vacuums to take bad stuff out of the air. According to new research, the solution could be as simple as sprinkling rock dust in farm fields.
Seriously. Researchers recently proposed that farmers should spread crushed volcanic rock dust on their fields. They suggest that if it becomes common practice in China, the U.S., and India — which are the countries that emit the most CO2 — agricultural fields in those countries could absorb nearly 1 billion metric tons of CO2. That could potentially play a huge role in keeping the climate from warming more than 2 degrees Celsius, which is the limit set by the Paris Climate Accord.
The method is called enhanced rock weathering, and it works by taking advantage of some really cool chemistry. When you dissolve volcanic, silicate rock in rainwater, its atoms rearrange into an ion called bicarbonate. But to do this, it needs some carbon. Where does it get the carbon for bicarbonate? The atmosphere, of course. These bicarbonate ions then find their way into streams, and eventually the ocean to be stored as solid, carbon-based minerals.
This might even do more than curb climate change. The researchers say that nutrients in silicate rock fields might also increase soil quality, leading to better crop yields while potentially lessening the need for fertilizers.
The best part is that it won’t require the farmers to do anything different than they already do. Many farmers spread crushed limestone in their fields to help regulate soil nutrients and acidity, so for them, it would only be a matter of switching out agricultural lime for a different kind of rock dust.
So why aren’t we doing this already? Well, this is all theoretical at the moment. It’s based on some complex environmental modeling, which, while useful, will need to be verified through long-term trials. Also, we don’t know what kinds of harmful environmental effects it might have.
But still, it’s pretty cool. It shows that the solutions to climate change don't have to be complicated.
Let’s recap what we learned today to wrap up. Starting with
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CODY: Today’s stories were written by Kelsey Donk, Grant Currin, and Cameron Duke, 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!