Researchers have found bacteria beneath the Pacific floor that may be thousands or millions of years old, their metabolism so slow that they’re basically in a state of suspended animation.
Call it survival of the slowest: Extraordinarily old, bizarrely low-key bacteria have been found in sediments 100 feet below the sea floor of the Pacific Ocean, far removed from sunlight, fresh nutrients and what humans would consider anything interesting to do.
Some of these organisms, scientists say, could be at least 1,000 years old. Or maybe millions of years. Their strategy for staying alive is to be barely alive at all. Their metabolism is dialed down to almost nothing, an adaptive advantage in a place with so few resources. The bacteria that survive are the ones that can satisfy themselves with minute traces of oxygen and a parsimonious diet of organic material laid down millions of years ago.
Such buried bacteria have been found before, but a new study, published Thursdayonline by the journal Science, has provided the clearest look at their glacial pace of existence. The conclusion, in short, is that microbes can putter along at extremely low rates of oxygen respiration, their numbers limited only by the paucity of energy available in the buried sediment.
“These organisms live so slowly that when we look at it at our own time scale, it’s like suspended animation,” said Danish scientist Hans Roy, a biologist at Aarhus University and the lead author of the study. “The main lesson here is that we need to stop looking at life at our own time scale.”
An ancillary message is that human beings should not be too chauvinistic about what constitutes, or characterizes, a living thing.
There are a lot more nuances to nature than scientists realized just a few decades ago.
The ingenuity of life gives hope to researchers looking for evidence of life beyond Earth. Extraterrestrial life could conceivably be detected by robotic probes, for example, in the Martian subsurface, or in an ice-
covered ocean on a cold moon farther out in the solar system.