The secret mission to unearth part of a 142-year-old experiment

It was 4 o'clock in the morning, well before sunrise, and cold. A light wintry mix of rain and snow was falling. The lousy weather was a relief, as it meant even less of a chance that someone might randomly pass by. The small group of scientists didn't want anyone to see what they were about to do.

They'd brought flashlights, a shovel, a trowel, a tape measure and an old map. The map looked more like a blueprint than a pirate's guide to buried treasure. Still, it did show the secret location of something precious stashed away underground.

The researchers had gathered together to dig up part of an experiment: an unusual long-term experiment that started in 1879 on the campus of what is now Michigan State University.

A botanist named William Beal wondered how long seeds could remain viable underground. So he designed an audacious study to find out, knowing full well that the answer might not come in his lifetime.

Frank Telewski, a professor of plant biology at the university, explains that Beal got 20 glass bottles. "Those 20 bottles, he filled up with a sandy seed mixture," says Telewski. "And the sandy seed mixture contained 21 species of plants, with 50 seeds per plant."

The plants were just common weeds. The idea was to find out, if farmers faithfully weeded their plots, how long these annoying plants could keep coming up from seeds already in the dirt.

Beal buried the bottles in the ground, keeping the location private so it wouldn't get disturbed. Every five years, he dug up one bottle and checked to see if the seeds inside would germinate. In 1910, when Beal retired, he passed on the experiment to a colleague, who later passed it on to a colleague and so on.

The study has lasted far longer than Beal intended because its caretakers decided to stretch it out. Instead of every five years, they switched to digging up a bottle every 10 years. Then, every 20 years. Telewski helped unearth a bottle in 2000, when he took over the experiment from a colleague. That year, only a couple of different weeds were still able to sprout.

As Telewski thought about digging up his second bottle, which was supposed to happen in 2020 (the excavation got delayed until this month, because of the coronavirus pandemic), he thought about the future. "I decided we needed to pass this on to the next generation, as I turned 65 last year," says Telewski. He picked three relatively young colleagues at the university to be the new caretakers and join him as he dug up a bottle.

One of them was David Lowry, who recalls first hearing about this famous experiment 20 years ago, when he was an undergraduate student in California. "I was blown away by the length and time at which it was occurring," he says. "I never imagined I'd be involved as well."

Telewski went to Lowry's office a couple of years ago and handed him the map. "And [Telewski] said, you know, in case something happens to me, you have the map. And a couple of months later, he had a stroke," recalls Lowry. "Fortunately, he mostly recovered from that. But there was a moment where it was like, 'Wow, I'm really glad that that handoff had occurred.' "

Even with the map and with Telewski healthy enough to lead the way, it was actually hard to find the right spot to dig in the dark. At first the team got slightly off track, then figured out its mistake and started digging again. Birds began waking up and chirping, and the team worried that it wouldn't be done before sunrise.

Lars Brudvig, another one of the new caretakers, said the whole experience of working on this felt different from the research he has done in the past.

"Almost like more pressure … than normal," says Brudvig. "Because I'm part of this bigger process, it's bigger than me, and I really want to make sure that it's done right and carried forward properly — both for the generations of plant biologists in the past who have been involved, but also for those generations that are still to come who will be involved in the future."

He and Lowry watched as Marjorie Weber, the third new caretaker, got down onto the ground and stuck her head into the hole. She groped around in the dirt, feeling tree roots and then something smooth.

"I think I found it," she exclaimed, and everyone cheered. Then a moment later, she reported, "Wait — maybe not. ... Oh. It was a rock." Everyone groaned.

A microbiologist named Richard Lenski looked on. "The others were digging and trying to figure everything out, and I sort of held the map and held it under my jacket to keep it dry at one point. That was my hard work," says Lenski. "I was wondering if cops might show up at some point."

Lenski wasn't part of the Beal experiment; he'd asked to come along as an observer. He has a special interest in long-term studies because he has his own going on just across campus. He started it in 1988, to study bacterial evolution, and recently picked a younger successor to carry it on.

"I like to think of our experiment as long term, both in the past and going forward," says Lenski, but the Beal seed-viability experiment "puts our experiment to shame in that respect. This is a pretty amazing, unique aspect of science."

Finally, Weber said, "OK, I — for real — found it!" Telewski greeted the bottles as if they were old friends. "Wow!" he said. "Oh, wow! Hello, bottles!"

Weber says it was really cool to pull a bottle out of the ground, knowing that "the last person to touch it was professor Beal, 140 years ago, you know, this person who was writing letters to Darwin."

The researchers immediately took the bottle to a lab. They spread out almost all of the contents onto potting soil.

A molecular biologist named Margaret Fleming removed a couple of seeds, ones from a species that hasn't germinated in about 100 years. The plan is to analyze those seeds to see if any of the cellular machinery is still active inside, even if the seeds can't germinate, using genetic tools that were unimaginable in Beal's day. What's more, Fleming and Weber are the first females to work on this project in its long history, showing that it's more than technology that changes.

The researchers waited and waited for about a week. Then, on the afternoon of Friday, April 23, Lowry checked the tray of seeds and saw one tiny green seedling. That means at least one old seed could still germinate, and more could sprout in the days to come.

"We know that seeds can last a really long time in perfect conditions, like in seed storage vaults or the permafrost," says Weber, who notes that Beal's original question is still relevant. "We don't really know how long seeds can last in the soil. And that's where most of the seeds are."

She and the other new caretakers are all in their 30s and 40s now, but they'll eventually have to choose their successors to carry the study forward. Telewski thinks they should do it before the next excavation, in 2040.

"If I'm fortunate, I'll be 85," says Telewski, "and I sure hope I can be there as a spectator and can watch the team dig it up with their new colleagues."

But, like Beal, no one on the current team is going to see the end of this experiment. With four bottles left in the ground, the study should go on for another 80 years.

Copyright 2021 NPR. To see more, visit https://www.npr.org.

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