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 60-second science. I'm Aline Ogenbrun.

Fossil footprints help tell us how ancient people lived, but such physical impressions are hard to find.

You get all of these footprints from different species in the same time period interacting,

and you can't see them all the time. And some of them you can never see, with the

eye that is, but we can still detect them with geophysical sensors. Cornell University archaeologist

Thomas Urban. He and colleagues use ground penetrating radar, GPR, to detect invisible traces

of footsteps in White Sands National Monument in New Mexico.

Their GPR device goes back and forth over an area in a grid pattern, which ultimately creates a 2D

radar gram. The technique detects subtle differences in ground density.

Speaking about one set of otherwise imperceptible animals' footprints, he says,

these were caused by compression of sediment beneath the animal's track, and they relate to the

weight and momentum of the animal. Twelve thousand years ago, the White Sands area was a large,

muddy flat, which was covered with footprints from various species.

Urban is excited about the stories so many footsteps suggest.

For example, the researchers found no evidence of shoes or sandals.

They did find human and animal tracks crossing each other,

which suggests the prints were left during a hunt.

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