A diverse lot of creatures sprawl over our planet. Plants, wildlife, humans, microorganisms- there is an abundance of it all. But what happens when one discovers that there is a place on earth that doesn’t support any such life form? As a result of Africa and Asia’s split up, Ethiopia became home to Danakil, a geological depression. Danakil, in turn, houses the Dallol sulphur springs that spread across a volcanic crater that consists of extremely hypersaline and hyperacid pools. It is here that European scientists have found an absolute lack of life form, including microorganisms!
This is a startling discovery, as any landscape with water content has been considered to be capable of supporting life. This hypothesis has been one of the major points while scientists attempt to explore habitable environments in space. While Dallol’s lakes obviously show the existence of liquid water, no life form is incapable of residing in them. These pools also reflect a negative pH level. For reference, the pH level scale goes from 0 to 14, with 0 being extremely acidic and 14 being extremely alkaline. Additionally, the area experiences stifling weather, with even winter temperatures rising higher than 45 degrees celsius.
The research was conducted by the French National Centre for Scientific Research (CNRS) who claim to have used various methods in order to ensure the legitimacy of the conclusion. This included a detailed sequencing of genetic markers to detect and classify microorganisms, fluorescent flow cytometry to identify individual cells, microbial culture attempts, chemical analysis of brines and scanning electron microscopy with X-ray spectroscopy. Biologist Purificacion Lopez Garcia comments “After analysing many more samples than in previous works, with adequate controls so as not to contaminate them and a well-calibrated methodology, we have verified that there's no microbial life in these salty, hot and hyperacid pools or in the adjacent magnesium-rich brine lakes”.
According to the article published in the journal Nature Ecology & Evolution by the team, there are two elements that prevent the existence of life forms. One, the abundant presence of chaotropic magnesium salts that breaks hydrogen bridges and denatures biomolecules and the deadly combination of the hypersaline and hyperacid conditions along with the high temperature.
Despite the absolute-sounding claim, the authors have also mentioned that the presence of halophilic archaea has been found in the desert and the saline canyons near the hydrothermal site, but not in the pools. The researchers further added that any conclusions in astrobiology will require an analysis of all types of alternatives and prudence with the interpretations.
The evidence also brings to light the fact that there may be more such places on the planet that are completely sterile despite the presence of liquid water.
With inputs from IANS