The Dallol hydrothermal pools are harsh environments. (Credit: Shutterstock)
Other-worldly, green, and yellow is the color of the scorching hot, the landscape of the Dallol volcano, in the northern part of Ethiopia. This alien-like world filled with hydrothermal swimming pools are some of the most extreme environments on the planet, and some of them seem to be completely devoid of life, according to a new study.
The various forms of life on our planet have adapted to survive under some pretty harsh conditions, in places which are superhot, superacidic or supersalty, just to name a few, said the study’s senior author, Purificación López-García, the director of research at the French National Centre for Scientific Research.
But life can survive in an environment that is a combination of all three of these terms and conditions, such as in the colorful water of the Dallol hydrothermal area?
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In order to figure out whether or not this extreme environment, to exceed the limits of life on our planet, researchers have sampled a number of brine swimming pool water with a high concentration of salt in the area. Some of them were very hot, salty and sour, while the others were still very, very hot and salty, but not too acidic or alkaline. The scientists analyzed all of the genetic material found in the samples, identifying organisms that live there.
Some of the smaller pools were filled with high sodium, chloride, a condition in which some organisms are able to withstand; in the more extreme environments of high concentrations of magnesium, salt-based, harmful for the life, because the magnesium will break down the cell membrane, Lopez-Garcia said.
In the most extreme environments, which were not very acid, spicy, and magnesium salts, the researchers found no DNA, and no trace of a living organism, according to the study. The scientists did detect a hint of the DNA of single-celled organisms, called archaea, as they are “forced conditions”, in which monsters, Lopez-Garcia said. This means that the sample has been taken and saved to the strengthening of the material — imagine zooming in on a picture to see if there is a very small amount she had missed. However, the researchers ‘ hypothesis is that this is a small amount of DNA, it is likely to be the result of an infection from a nearby salt flat, is brought to the attention of the people who are visiting the area, or the wind.
On the other hand, in the extreme, the ponds, the researchers found a high diversity of micro-organisms, and again, especially in archaea. “The diversity of the archaea, it is really great and very friendly,” Lopez-Garcia said. The researchers found that there is a number of archaea that are known to live in areas with a high concentration of salt, and a number of the scholars had no idea it would be able to survive, even in the less saline ponds.
The findings suggest that there is a gradient of the most extreme environments, some of which harbor life, and others don’t, and would be able to serve as a bit of a warning in the quest to find life elsewhere in the universe, she added. “The idea is … when a planet with liquid water on the surface, is habitable,” she said. However, if it is dead in pools of Ethiopia, as may be imagined, the water is probably a necessary condition, but it is far from enough.”
What’s more, with the help of electron microscopes, the researchers also found that the presence of a platform for distributed computing, or mineral precipitates, which can be similar to the small cells in the samples taken from both the concentrate and the pools, and the port-of-life, and Lopez-Garcia said. “If you go to Mars, or to fossil environments, and you will see a small round thing, you might be tempted to say that these microfossils, but they can’t do it.”
To prove that life does not exist
There were a number of weaknesses in the study, by John Hallsworth, a professor at The Institute for Global food security at Queen’s University, Belfast, Northern Ireland, wrote in an accompanying commentary, also published in the journal, Nature, Ecology, & Evolution. For example, the researchers ‘DNA analysis could not determine if the detected organisms were alive or active, and it is unclear if the measurements of the water factors such as pH, have been done accurately,” he wrote.
However, the team managed to characterise the geochemistry and microbial diversity of a large amount of the salt that is spread out on a wide range of physico-chemical conditions, revealing the extensive diversity of the archaeal communities present,” Hallsworth wrote.
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What’s more, a couple of months ago, another group of researchers came to the opposite conclusion after they sampled the water in the Dallol area. In the extreme lakes of the region, the researchers found that the archaea are thriving,” and a variety of types of evidence suggests that these micro-organisms do not come from any kind of contamination, said Felipe Gomez, a biochemist in Spain, in the Centre of Astrobiology and lead author of the study, which was published in May in the journal Scientific Reports.
“In view of the risk of detection of any type of contamination, microbiologists who work in extreme environments takes a lot of precautions in order to avoid it,” he said. “As part of our work, which we have included in the sample, in a completely sterile conditions, or which is free of the infection. It is not clear why there is a discrepancy between the studies, however, “it is true that they do not see what we have to report,” that this does not imply that the earlier findings are incorrect, ” he said. “There’s more work to be done.”
But the old paper is a “weak” because the researchers are only trace amounts of a species of archaea that are similar to those of the archaea live in the neighboring salt valley, and it is not enough to prevent infection, Lopez-Garcia said.
“The spread has been active in the area,” so this is the track of the archaea might have been the wind, or of the tourists, which is similar with the way her team also found traces of archaea, but the assumption is that they were contamination from the nearby salt flats, ” she said.
The new findings are published in the Oct. 28 in the journal Nature, Ecology, & Evolution.
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Originally published on Live Science.