One of the things that we had learned a long time ago is that you can do things in a laboratory

that mean exactly nothing in the world.

Rusty Rodriguez has seen some pretty cool things in the laboratory.

He's a microbiologist who studies the relationship between plants and microbes.

In the late 1990s, he and his team collected samples of grass from Yellowstone National Park,

where the geothermal soils can get really hot.

And so what we found was that all of the plants in these hottest zones all had one dominant

fungus that we could isolate from them.

And when they heated up the grass in the lab without the fungus, the grass would wilt

and die.

So it seemed, at least in the lab, that the grass needed the fungus to stay alive in the

hot soil.

But to know for sure, they needed to get out of the lab.

So they went back to Yellowstone to set up an experiment.

On one side of a box, they planted the native grass with the fungus that lives inside it.

And on the other side, they planted the grass without the fungus.

And then they left for a year.

And when they came back, Rusty didn't know what they would find.

The anticipation just during the hike, I think it's only like a mile or two in.

It's not that far.

But we were talking about, well, gosh, I wonder what it's going to look like.

Do you think they survived?

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