Understanding the human body is a team effort. That's where the Yachtel group comes in.

Researchers at Yachtolt have been delving into the secrets of probiotics for 90 years.

Yacold also partners with nature portfolio to advance gut microbiome science through the global grants for gut health, an investigator-led research program.

To learn more about Yachtolt, visit yawcult.co.

.jp. That's Y-A-K-U-L-T.C-O.J-P. When it comes to a guide for your gut, count on Yacult.

This is Scientific American's 60-second science. I'm Christopher in Taliatta.

Blue whales are the largest animals ever to exist on Earth.

But they're still tough to track, because they live underwater where we can't easily see them,

and often in remote areas, like the Southern Ocean.

But the whales' songs can travel hundreds of kilometers underwater, so scientists often listen for them instead.

By the way, that's sped upton times so you can hear it.

Over the years, these eavesdropping biologists have noticed a mysterious trend,

that certain blue whale calls are gradually

lowering in pitch over time. For example, here's a call from 2002, followed by one from 2017.

It has been observed for many blue whale population worldwide.

So this phenomenon has to have a worldwide explanation.

Emmanuel Le Waugh is a bioacoustician at the University of New South Wales in Australia.

She did the work at the University of Breast in France.

Her team confirmed the phenomenon holds true for populations of blue whales

in the southern Indian Ocean, too. And they suggest one reason may be that whale numbers have

rebounded from the days of Captain Ahab. More whales means individuals don't have to shout as loud

to be heard by other whales. And because of an anatomical peculiarity in the way whales sing, the softer they

...