The fascinating experiment underway for 145 years – 03/21/2024 – Science

On a freezing April morning in 2021, American scientists took an old map, flashlights, a shovel and a flexometer to search for a precious treasure buried 145 years ago.

In command of the small group was Professor Frank Telewski, biologist and leader of this small society of researchers at Michigan State University and guardian of the map that was inherited for several generations.

The area indicated on the map was located and a hole began to be dug with a shovel. Scientist Marjorie Weber —the first woman to join the group— began to dig carefully with her hands, to prevent a blow from the shovel from damaging the treasure.

She felt something hard beneath the ground, which caused everyone to cheer. But they soon discovered that it was the root of a tree. She continued a little longer, until she found something else: a stone. Something was wrong.

They checked the map and realized they had missed their initial calculations by about two feet. So they went back to digging some more.

And there it was: a half-liter glass bottle filled with sand and seeds. Weber says it was like “bringing a baby into the world.”

The treasure had been buried in 1879 and after 15 decades it was removed from the ground by this group of scientists working on one of the longest experiments in the history of biological sciences.

It was started by botanist William J. Beal in the past to determine how long a seed remains viable for germination.

The mission was passed between several guardians, many of whom did not see — and perhaps will not see — its end. Completion is scheduled for 2100. Although even that could be extended.

“Being part of the Beal buried seed experiment was, without a doubt, one of the highlights of my career,” says Professor Lars Brudvig, one of the group’s selected scientists, to BBC News Mundo, the BBC’s Spanish-language service.

“Unearthing and holding the bottle of 2021, last touched by Beal himself 141 years earlier, and then watching plant after plant germinate from those seeds… wow. It was a joy and an honor to be part of this team.”

The weed

William J. Beal was a botanical scientist at Michigan State University’s College of Agriculture. He wanted to help local farmers increase agricultural production by eliminating weeds.

This type of weed seemed to grow out of control and at that time, in the late 19th century, farmers had to use hoes and spend a lot of time trying to keep it at bay.

Therefore, Beal wanted to understand their behavior and decided to investigate how long weed seeds could persist underground, being viable for germination.

To find an answer, he decided to fill 20 glass bottles with 50 seeds from 23 weed species. He buried them face down — to prevent water from entering — on the grounds of Michigan State University. And so as not to forget the exact location, he made a map.

The initial plan was to dig up a bottle every five years to see if the seeds still worked.

He was responsible for monitoring the experiment in the first decades, a time when some seeds continued to germinate.

At the age of 77, he retired and left the experiment in the hands of his colleague Henry T. Darlington, a 31-year-old professor of botany who had many years ahead of him.

Beal’s ‘Spartans’

Seeing that the viability of the seeds was maintained in the first five years, in 1920 the period increased to ten years. And as they continued to germinate, in 1980 the wait was extended to 20 years.

Over the decades, the experiment had seven guardians. The “Spartans”, as they call themselves, want these bottles to remain stored in a place away from curious people.

“It’s not marked or guarded, but it’s quite safe and no one would come across it by chance. If you walked past it, the place would look like any other part of our 2,000-plus acre campus,” says Brudvig.

“We used a map to triangulate the location by key landmarks.”

Since 2016, the leader of the experiment has been Frank Telewski, who appointed a guardian of a copy of the map in case something happened to it.

In 2021, they unearthed bottle number 14 of the 20 that Beal placed underground.

The sleeping beauties

After almost 150 years, some seeds continue to germinate, which has given scientists more information about their dormancy or longevity.

Unlike decades ago, experts are now able to carry out studies that they could not have imagined in Beal’s time, such as DNA research.

A recent molecular genetic test confirmed the presence of a hybrid Verbascum blattaria It is Verbascum thapsusor mullein, which was accidentally included among the seeds in jar number 14.

Apparently, Verbascum They are the plants with the greatest dormancy, as others have lost their germination capacity in the first 60 years.

While Beal’s initial goal was to help farmers eliminate weeds by determining seed longevity, after 144 years there is still no answer.

Brudvig says the seeds they have are like Princess Aurora from “Sleeping Beauty.”

“The latent seeds are alive, but ‘sleeping’ and waiting for the right stimulus before waking up (germinating). But while Princess Aurora waits for her true love’s kiss, the seeds in the soil seed bank await stimuli like sunlight , adequate temperature or adequate humidity conditions that will make them germinate and begin to grow”, he explains.

“A fundamental issue is that seeds from different plant species can survive in a dormant state for various periods of time,” continues Brudvig.

“At some point it’s too late, even when given the right stimulus. For the plant species tested in the Beal seed experiment, we learned that this time frame ranges from 5 to 140 years.”

Do weeds never die?

The group takes great care with seed management to achieve consistent results. They dig up the seeds at night to prevent sunlight from influencing them in any way. And in laboratories they are able to generate conditions from the natural environment.

“We used a growth chamber with carefully controlled temperature, light and humidity when germinating the plants for this experiment,” says Brudvig.

In addition to the questions that Beal originally posed, the experience remains relevant to answering additional questions that the botanist set out to resolve.

“The relevance of the experiment has also grown over time, in ways that I’m not sure Beal could have imagined nearly 150 years ago,” says the scientist.

For example, both rare native plant species and problematic invasives can remain dormant in the soil, sometimes for many years, increasing potential benefits and challenges for managing native ecosystems.

Knowing more about this could help efforts to restore native ecosystems, such as grasslands and forests, from areas of ancient cultures.

“Our findings help document which plant species, such as Verbascumwhich may be problematic weeds for a restoration project like this, and which other species may not be, depending on how long a field was cultivated before being restored,” explains Brudvig.

It will still take several generations of Spartans to reach bottle number 20, which should be unearthed in the year 2100. But scientists have not ruled out the possibility of extending the period between each excavation.

Will they germinate more than 220 years later? Do weeds never die, as the saying goes?

These discoveries will be the responsibility of other generations.