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

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

During the last ice age, the northern half of North America was blanketed by ice.

But along the Pacific coast of Canada, some land remained bare. It was a place where animals and plants could thrive.

And humans, too. Archaeologists have found stone tools and cave sites 12 to 13,000 years old in the coastal Pacific Northwest.

One find was a mastodon rib with a bony weapon in it,

and now scientists at the Hukai Institute and the University of Victoria have made a spectacular discovery,

clay soil trampled by human feet, the oldest footprints uncovered in North America.

Researchers were digging several feet below a modern-day beach on British Columbia's

Calvert Island, about 250 miles northwest of Vancouver when they discovered the tracks.

They found 29 in all. Some had toes, arches, and heel prints, indicating the people

who left them were probably barefoot, and using a shoe size measurement chart, similar to the kind

you find in a shoe store, they determined that the footprints likely belong to a child and two adults,

who lived and walked the area some 13,000 years ago. The results are in the journal, Plus One.

The tracks are not in a line, like the famous Latoli footprints in Tanzania.

Instead, they're facing different directions, suggestive of people gathering.

Or perhaps the authors write, they could be the footprints of people getting out of a boat,

headed towards higher and drier land, still on the move.

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