Have you ever felt really, really old? This author just recently changed the first number of his age to three, and I can certainly say that on some mornings I really feel like a geezer.

Of course, age is relative. For example, the oldest known living person – thought at the time of writing to be the 117-year-old Japanese lady Kane Tanaka – is nothing but a baby compared to some other species on the planet.

But then there are those forms of life that make the passing of decades, centuries, or even millennia seem insignificant. Just recently, scientists discovered microbes that were still alive after spending 100 million years buried on the bottom of the Pacific Ocean.

Let’s put that into perspective, shall we? Tyrannosaurus Rex, one of the most famous dinosaurs, wouldn’t come into being for another 30 million years or so when these single-cell organisms were young.

Nothing even resembling the earliest lineage that eventually became humans existed at the time. That’s how old they are.

And they pulled their feat of survival deep beneath ocean sediments, with practically no food or oxygen. Tough little troopers, they are.

Searching for Sediments

The research team that found the microbes comes from a variety of Japanese and American universities and science institutes. Ten years ago, the scientists gathered sediment samples from the South Pacific Gyre.

This part of the Pacific Ocean – at the depth 20,000 feet – is one its harshest and most inhospitable to all life. There are so little nutrients available that practically nothing lives there, wrote LiveScience.

Not only that, the team harvested the samples from 328 feet beneath the ocean floor. Meaning that they were drilled up from underground.

Safe to say, that’s not a place you would expect to find life in. The scientists weren’t exactly holding their breath either.

“Our main question was whether life could exist in such a nutrient-limited environment or if this was a lifeless zone,” the study’s lead author Yuki Morono, senior scientist at the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), told Phys.org.

Unlikely as it might be, the team found some oxygen in the sediment. Apparently oxygen can become trapped between the layers of sediment that slowly sink down from the ocean surface.

So, if there’s oxygen, there could be life, right? Well, the scientists did find a bunch of microbes, but they seemed pretty lifeless to the research team.

Nonetheless, they took the microbes to the laboratory to run some tests with them. Seems like a thing for scientists to do.

Hungry, Hungry Microbes

Once in the lab, Morono’s research team took great efforts to make sure that the ancient microbes weren’t contaminated with modern ones. They sterilized the entire room and used completely sealed feeding tubes and equipment.

Then, they took a closer look at the microbes. The little things indeed seemed to have given up the ghost and showed no sign of activity whatsoever.

Still, out of scientific persistence – or maybe just for the heck of it – the team decided to give the microbes something they might like to eat, like carbon and nitrogen.

Imagine their surprise when the cells slurped up the food and popped right back to life.

“At first, I was skeptical, but we found that up to 99.1% of the microbes in sediment deposited 101.5 million years ago were still alive and were ready to eat,” said the astonished Morono.

Not only were they ready to eat, they were ready to breed – or, well, divide since they’re just microbes. Within 68 days, the original 6,986 microbes had quadrupled in number.

Basically, they were only taking a 100-million-year power nap.
‘No Limits to Life’

While there might not be many practical applications for ancient cells, the scientific implications of the study are astounding.

“We knew that there was life in deep sediment near the continents where there’s a lot of buried organic matter,” said Steven D’Hondt, professor from the URI Graduate School of Oceanography and the study’s co-author.

“But what we found was that life extends in the deep ocean from the seafloor all the way to the underlying rocky basement.”

Morono says that life in the sub-seafloor is much slower to that on the surface. As such, evolutionary speed of the organisms dwelling there is slower, which opens up a whole new branch for research.

“We want to understand how or if these ancient microbes evolved. This study shows that the sub-seafloor is an excellent location to explore the limits of life on Earth,” Morono said.

D’Hondt seems even more optimistic about the possibilities Morono’s discovery has opened up. If these microbes could survive in the oldest seafloor sediments, who knows what else is lurking down there.

“What’s most exciting about this study is that it shows that there are no limits to life in the old sediment of the world’s ocean,” he said.