{"id":3841,"date":"2022-03-09T22:00:00","date_gmt":"2022-03-09T22:00:00","guid":{"rendered":"https:\/\/modernsciences.org\/staging\/4414\/?p=3841"},"modified":"2022-02-23T09:14:23","modified_gmt":"2022-02-23T09:14:23","slug":"this-costa-rican-lake-may-reveal-how-mars-could-have-hosted-life","status":"publish","type":"post","link":"https:\/\/modernsciences.org\/staging\/4414\/this-costa-rican-lake-may-reveal-how-mars-could-have-hosted-life\/","title":{"rendered":"This Costa Rican Lake May Reveal How Mars Could Have Hosted Life"},"content":{"rendered":"\n

Near the center of Costa Rica is its famous volcano called Volc\u00e1n Po\u00e1s<\/em>, whose peaks house two crater lakes: the inactive southern Lake Botos and the active northern Laguna Caliente<\/em>. A team of scientists took samples from the northern volcanic lake, known for being one of the most acidic in the world and for having liquid sulfur (S) floating near its bottom, and found that the organisms there employed a wide gamut of genes to allow them to survive such harsh conditions\u2014a fact that the research team believes might hold clues as to how organisms, if any, might survive on our neighbor planet Mars.<\/p>\n\n\n\n

Published in the journal Frontiers in Astronomy and Space Sciences<\/em><\/a>, the study encompassed a genetic study of the microbes that lived in the lake water; this included the single microbial genus Acidiphilium<\/em>, which was described in a study published in the journal Astrobiology<\/em><\/a> back in 2018.<\/p>\n\n\n\n

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Volc\u00e1n Po\u00e1s sita near the center of Costa Rica; this volcano rises to some 2,700 m (8,850 ft) above sea level. The volcano possesses two crater lakes: the active Laguna Caliente to the north, and the inactive Lake Botos (pictured) to the south. (Ortiz, 2009)<\/figcaption><\/figure><\/div>\n\n\n\n

The current research team, led by the University of Colorado Boulder<\/a> astrobiologist Justin Wang, returned to the volcanic lake after Volc\u00e1n Po\u00e1s erupted back in 2017<\/a>; their goal was to examine what effect the recent eruptions had on the biodiversity present in the lake water.<\/p>\n\n\n\n

Sweeping genetic analyses revealed that while Acidiphilium<\/em> was still the predominant genus present in the water, a couple of other microorganisms were also present in the mix. Additionally, these microorganisms possessed genes that conferred to these microbes both acid and heat resistance\u2014no doubt necessary adaptations that helped them survive post-eruption.<\/p>\n\n\n\n

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Laguna Caliente (pictured) is known as one of the most acidic lakes in the world, and is perhaps one of the harshest environments where life has been found. (Hernandez, 2018)<\/figcaption><\/figure><\/div>\n\n\n\n

Alongside these survival genes, the team also found additional genes that allowed these microbes to metabolize substances that other organisms might consider toxic, like sulfur (S) and arsenic (As). This was paired with genes for carbon fixation<\/em>\u2014genes that are commonly found in plants, which allow them to convert carbon into organic compounds, among other functions.<\/p>\n\n\n\n

Said Wang: “We expected a lot of the genes that we found, but we didn’t expect this many given the lake’s low biodiversity. This was quite a surprise, but it is absolutely elegant. It makes sense that this is how life would adapt to living in an active volcanic crater lake.”<\/p>\n\n\n\n

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Barnacles now take root near the vicinity of hydrothermal vents, which regularly blast the surrounding water with nutrients necessary for life\u2019s processes at these depths. (NOAA, 2013)<\/figcaption><\/figure><\/div>\n\n\n\n

What\u2019s important to Wang and the team is that these organisms found ways to harness energy from chemical reactions, other than the Sun, to power their biological processes; this, in turn, gave scientists insights into how organisms may evolve in worlds beyond Earth, whose surfaces won\u2019t receive as much sunlight as Earth does.<\/p>\n\n\n\n

Experts also think that life on early Earth may have started in environments similar to those in Laguna Caliente\u2014hydrothermal <\/em>environments deep underwater, where organisms would have been shielded from the then-harsher effects of ultraviolet radiation from the Sun<\/a>, given that Earth wouldn\u2019t develop a distinct ozone layer until the onset of the Great Oxidation Event<\/em> (GOE) some 2.4 to 2 billion years ago<\/a>.<\/p>\n\n\n\n

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Ancient Mars may have been covered with oceans of water, much like how Earth is now; to scientists, this may mean that the Red Planet may have (or may still) host life. (Wikimedia Commons, 2009)<\/figcaption><\/figure><\/div>\n\n\n\n

To Wang and team, early Mars may have been a similarly wet and volcanically-active world<\/a>, same as early Earth; thus, organisms that may have existed (or perhaps may still exist) on the Martian surface did so using similar processes that sustained Earth\u2019s microorganisms until the onset of our current oxygen-rich atmosphere.<\/p>\n\n\n\n

“Our research provides a framework for how ‘Earth life’ could have existed in hydrothermal environments on Mars,” Wang followed. \u201cBut whether life ever existed on Mars and whether or not it resembles the microorganisms we have here is still a big question. We hope that our research steers the conversation to prioritize searching for signs of life in these environments.”<\/p>\n\n\n\n

References<\/h2>\n\n\n\n