Shark Sounds, Molecules on Mars and Continued Federal Cuts
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Hi, I'm Clara Moskowitz, senior editor for space and physics at Scientific American. Like many kids, I once dreamed of becoming an astronaut. While I never made it to space, my work at Scientific American has given me the next best thing.

Exploring the cosmos through stories and sharing its wonders with science lovers like you. When I research a story, I immerse myself in the reporting to bring you an exciting and accurate account. Over the years, I've covered breathtaking rocket launches, visited one of the world's highest altitude telescopes in Chile, and even trained for suborbital spaceflight. I love interviewing scientists who are exploring the mysteries of space.

If you'd like to learn about the secrets of dark matter directly from an expert, join me on April 9th for a live conversation with theoretical physicist Catherine Zurich. Subscribe to Scientific American today at sciam.com slash get sciam to attend this event and explore our vast, beautiful cosmos.

Happy Monday, listeners. For Scientific American Science Quickly, I'm Rachel Feltman. Let's kick off the week and wrap up the month with a quick roundup of the latest science news. We're going to eliminate an entire alphabet soup of departments and agencies. We're going to eliminate an entire alphabet soup of departments and agencies.

Last Thursday, the U.S. Department of Health and Human Services announced plans to cut 10,000 full-time jobs across the department. And another 10,000 individuals have already accepted voluntary retirements and buyouts. The new layoffs will hit the Food and Drug Administration, the Centers for Disease Control and Prevention, the National Institutes of Health, and the Centers for Medicare and Medicaid Services.

28 great divisions will become 15. The entire federal workforce is downsizing now, so this will be a painful period for HHS as we downsize from 82,000 full-time employees to around 62,000.

HHS Secretary Robert F. Kennedy Jr. said in a statement that the aim of these cuts is to save money and boost efficiency. Meanwhile, last week, the Trump administration also moved to cancel more than $12 billion in federal grant funding to state and local health departments. Axios reports that the main targets are grants for COVID testing, initiatives aimed at tackling health disparities, and vaccinations.

As of last Thursday, those cuts had reportedly already led to layoffs at the Virginia Department of Health. We will, of course, be watching these developments and keep you posted. But for now, let's move on to some exciting news from Mars. According to a study published last week in the Proceedings of the National Academy of Sciences USA, NASA's Curiosity rover has found the biggest carbon-based molecules ever seen on the Red Planet.

These long-chain alkanes are thought to have come from fatty acids, which are the building blocks of cell membranes in living organisms on Earth. Now, these long molecules aren't necessarily a smoking gun for Martian life. We know that fatty acids can form by way of chemistry instead of biology.

In fact, some scientists think we first got fatty acids on Earth thanks to the interaction of water and minerals in hydrothermal vents. So while fatty acids are necessary for life as we know it, it's possible they formed on Mars without life ever finding a way. Still, this finding is another point for Mars in the quest to determine potential past habitability.

Plus, since these compounds were found preserved in a 3.7 billion year old rock, the discovery gives scientists hope that if microbial life once existed on Mars, we might still be able to find signs of it.

Speaking of size superlatives, paleontologists are showing off a really freaking big dinosaur claw in pristine condition. It belongs to a new species of therizinosaur, which was described in a study published in the journal iScience last Tuesday. Writing for National Geographic, Riley Black explained that therizinosaurus were, generally speaking, a pretty weird bunch. The dinosaurs were descended from carnivores but had come to eat plants.

They were apparently kind of sloth-like, down to their three giant claws, except that they were also giant and covered in feathers.

But a specimen found in Mongolia's Gobi Desert back in 2012 has revealed a new species that stands out even in its weird family for having just two fingers instead of three. One of those fingers still has a sheath of keratin that would have protected the actual bone of the claw. This protective covering also added length, creating a talon nearly a foot long.

Scientists think the new species likely lost its third digit as a result of evolution. While the creature's sharp claws look like something a raptor would use to tear at their prey, these oddballs probably use them to hook branches while foraging, which the authors of the new study think could have been done more efficiently with a two-fingered grasp than a three-fingered one.

We'll keep the creature feature theme rolling to wrap up with a couple of new papers on animal behavior under the sea. First, a new study on sharks. The predators are known for their stealth, but research published Wednesday in the journal Royal Society Open Science is absolutely blowing up their spot. While the study authors note that sharks are not historically viewed as active sound producers, the researchers managed to catch rigged sharks making little clicking noises.

The study's lead author reportedly heard some unusual sounds while working with sharks back in grad school, but wasn't able to investigate further until recently. In the new study, she and her colleagues observed 10 rigged sharks in tanks tricked out with underwater microphones. They caught the sharks making extremely short clicking noises, like shorter than a human blink short, so literally blink and you'll miss it stuff. And those noises reached a maximum of 156 decibels on average.

The sharks made a lot more noise when handlers first touched them, and the noises tended to subside as they got used to being held. That could mean these are deliberate sounds, like a "What's the big idea?" or "Guys, heads up, these humans are pretty handsy." But we'll need a lot more research to be sure about that one. And in case you're wondering, those clicks sound like this.

Sharks lack the swim bladder that most fish use to make noises, but researchers suspect the rigs make these clicks through the "forceful snapping" of their teeth. As a habitual tooth grinder, I can certainly sympathize. Since sharks are, generally speaking, a pretty toothy bunch, it stands to reason that other species could be producing sounds similar to these. And while sharks are potentially using sound to communicate, cuttlefish are apparently using visual tricks to mesmerize their prey.

Cuttlefish are known for having specialized skin cells that allow them to rapidly change color and create patterns for camouflage. Last month, a group of researchers published examples of different visual displays that one cuttlefish species might use to trick prey. The scientists recorded broad-clubbed cuttlefish seemingly mimicking floating leaves and branching pieces of coral, as well as generating some pulsing patterns. This created an effect that made it look like a dark stripe was moving down the cuttlefish's body.

That's kind of a surprising tactic, because to human eyes, it's like a flashing sign that says "cuttlefish incoming." But in a new study published last Wednesday in Science Advances, the same researchers argue that this passing stripe display helps a cuttlefish hunt by overwhelming a prey animal's senses. From the perspective of a crab, for example, these fast-moving stripes could distract from the actual movements of the approaching cuttlefish. So it was all very "pay no attention to the cuttlefish behind the striped curtains."

That's all for this week's News Roundup. We'll be back on Wednesday with special guest Wendy Zuckerman from Science Versus to talk about the science behind a big debate surrounding a certain sexual phenomenon.

Science Quickly is produced by me, Rachel Feltman, along with Fondam Wongi, Kelso Harper, Naima Marci, and Jeff Dalvisio. This episode was edited by Alex Sagiara. Shaina Posis and Aaron Shattuck fact-check our show. Our theme music was composed by Dominic Smith. Subscribe to Scientific American for more up-to-date and in-depth science news. For Scientific American, this is Rachel Feltman. Have a great week!