Biology

Bacteria found living in polar ice prompts rethink on climate and alien life

Bacteria have been discovered living in polar ice and snow, which was previously thought to be too harsh for them to thrive
Bacteria have been discovered living in polar ice and snow, which was previously thought to be too harsh for them to thrive
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Although the researchers took great care to ensure that the testing sites remained uncontaminated, curious wildlife meant some samples had to be disregarded
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Although the researchers took great care to ensure that the testing sites remained uncontaminated, curious wildlife meant some samples had to be disregarded
Bacteria have been discovered living in polar ice and snow, which was previously thought to be too harsh for them to thrive
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Bacteria have been discovered living in polar ice and snow, which was previously thought to be too harsh for them to thrive

Bacteria are hardy little creatures, but even they have their limits. One of those was previously thought to be polar ice and snow, but a new study from the University of York has now directly observed bacteria living in those conditions in both the Arctic and Antarctic regions. That discovery has implications for our understanding of the planet's past climate, as well as where we might hope to find life elsewhere in the universe.

In areas like Greenland and the poles, permafrost is thought to do a great job of preserving a detailed time capsule of the climate from Earth's deep history, by locking gases from the atmosphere into snow as it compresses into ice. Ice cores have been used to measure things like air pollution and carbon levels in the atmosphere at different points in time. They usually stretch back hundreds of thousands of years, but have been sampled as far back as 2.7 million years.

These calculations are usually based on the fact that bacteria can't survive in those conditions, so their biological processes won't mess up the readings. But that assumption might not hold true, as scientists have now seen bacteria alive and well in that hostile environment.

Working at carefully quarantined sites in both the Arctic and Antarctic, the York researchers sterilized samples of snow with UV light, and compared them to untreated samples. In doing so, they found that the natural snow contained traces of methyl iodide, a by-product of certain bacteria. Their presence could affect the CO2 levels detected in ice cores, altering our understanding of the Earth's past climate.

Although the researchers took great care to ensure that the testing sites remained uncontaminated, curious wildlife meant some samples had to be disregarded
Although the researchers took great care to ensure that the testing sites remained uncontaminated, curious wildlife meant some samples had to be disregarded

"As microbial activity and its influence on its local environment has never been taken into account when looking at ice-core gas samples it could provide a moderate source of error in climate history interpretations," says Kelly Redeker, lead author of the new study. "Respiration by bacteria may have slightly increased levels of CO2 in pockets of air trapped within polar ice caps meaning that before human activity CO2 levels may have been even lower than previously thought."

The implications of that aren't good news. If the pre-Industrial era CO2 levels were lower than earlier estimates, that means human activity is having an even bigger impact on the climate now than we thought.

On the other hand, there is some potential good news to the find as well. The fact that bacteria can survive in this harsh environment bodes well for life on other planets, which we might have previously dismissed as too cold. Liquid water might not be a necessity for a planet to be deemed habitable after all – water ice could suffice.

"The fact that we have observed metabolically active bacteria in the most pristine ice and snow is a sign of life proliferating in environments where you wouldn't expect it to exist," says Redeker. "This suggests we may be able to broaden our horizons when it comes to thinking about which planets are capable of sustaining life."

In future, the researchers plan to look deeper into the ice caps to see if they can find signs of active bacteria further down.

The research was published in the Journal of the Royal Society Interface.

Source: University of York

4 comments
kevan
definitely interested in how this find plays out, i guess it could be possible that the Bactria found may be somewhat new, only recently having adapted to living in that kind of environment, in that case i'd assume its probably not going to impact things like old ice core research too much, but on the other hand, maybe these little guys have been living out there in the snow and ice for millions of years.
NatureTV
Amazing all these "scientists" get it wrong again with their group think that everything in the universe is like Earth. The more we study Earth the more they find life where life 'can't exist': Too hot (Yellowstone), too deep (the trenches), too cold - north and south poles. Stop trusting the so called 'scientists" and have an open mind to new life forms outside the Earth and our solar system.... Can't wait till we find life on Mars, Jupiter and it's moons... much like life discovered on Earth that proved the so called experts wrong once again. Don't trust computer models for weather short or long term as they are based on the same false premises... so called Science Fail once again....
Gregg Eshelman
Air bubbles in ice are not hermetically sealed little time capsules. The ice will absorb gasses from the air trapped in the bubbles, thus altering the mixture. Just place an unwrapped fish along with some already frozen trays of ice cubes in a freezer to discover how well ice absorbs stuff. Examining the bubbles in old ice is pretty well useless for determining the composition of ancient air. I recall reading an article years ago about how byproducts from jet fuel had been found in ice brought up from a depth that should have pre-dated air travel.
JimFox
NatureTV Scientists don' t "get it wrong" - well they do but continue investigation until they find ever more accurate answers. If you don't trust scientists, then you must immediately stop using ALL modern devices, electricity, gas, cars- the list is endless. Otherwise you are nothing but an hypocrite- true?