WEBVTT - Could Some Microbes Live on Air Alone?

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<v Speaker 1>Welcome to brain stuff from how stuff works, pay their

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<v Speaker 1>brain stuff luring Vogelbon. Here, life's resilience keeps astounding us.

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<v Speaker 1>Unimaginable as it may seem, there's a thriving population of

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<v Speaker 1>microorganisms in the cold, dry, nutrient poor soils of Antarctica.

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<v Speaker 1>A study may have just revealed the secret to their survival,

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<v Speaker 1>and that revelation could transform our quest to find life

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<v Speaker 1>on other planets. Antarctica is a continent which famously goes

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<v Speaker 1>dark for months on end during the winter season, a

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<v Speaker 1>period in which it sees no sunlight. This presents a

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<v Speaker 1>big challenge to organisms who need to photosynthesize, that is,

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<v Speaker 1>convert solar light into food. Intense dryness is another hurdle.

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<v Speaker 1>Certain parts of the continent receive no precipitation whatsoever, and

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<v Speaker 1>even though Antarctica is covered in ice, drinkable water is scarce.

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<v Speaker 1>And then we have the issue of carbon. All known

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<v Speaker 1>life is based on this element, and yet very little

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<v Speaker 1>of it can be found in Antarctic dirt. But life

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<v Speaker 1>uh finds a way. For years now, biologists have known

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<v Speaker 1>about the existence of diverse bacteria communities in Antarctic as soils.

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<v Speaker 1>How could anything survive under such extreme conditions. To gain

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<v Speaker 1>some insight, a team of Australian and New Zealander scientists

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<v Speaker 1>took a hard look at micro filled dirt samples from

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<v Speaker 1>two ice free sites in eastern Antarctica. Both areas are

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<v Speaker 1>deserts where no plants can grow. The McMurdo Dry Valley's

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<v Speaker 1>region has even been compared to the surface of Mars.

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<v Speaker 1>The place has received no rainfall in almost two million years,

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<v Speaker 1>its humidity levels are staggeringly low, and ice, snow, and

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<v Speaker 1>liquid water are all practically non existent there. On December six,

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<v Speaker 1>the team published their findings in the journal Nature. They

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<v Speaker 1>reported seeing DNA traces from twenty three microbial organisms inside

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<v Speaker 1>those soil samples. By reconstructing the microbes genomes, the scientists

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<v Speaker 1>learned that many of these life forms had genes that

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<v Speaker 1>made them exceptionally good at processing carbon monoxide and hydrogen.

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<v Speaker 1>The researchers theorized that the organisms are able to meet

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<v Speaker 1>their energy requirements by pulling both of these gases, along

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<v Speaker 1>with carbon dioxide, straight out of the atmosphere. In other words,

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<v Speaker 1>because of Antarctica's shortage of sunlight and suitable water, as

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<v Speaker 1>well as nutrient poor soil, these microbes could be surviving

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<v Speaker 1>off of air alone. Should this be true, planets and

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<v Speaker 1>moons that were once written off as completely uninhabitable might

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<v Speaker 1>be able to sustain life after all. Maybe alien organisms

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<v Speaker 1>don't need drinking water or abundant sunlight on their homeworlds. Instead,

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<v Speaker 1>it could be that the only thing they require is

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<v Speaker 1>the right combination of atmospheric gases. But the study scientists

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<v Speaker 1>say more research is needed to see if this phenomenon

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<v Speaker 1>exists in other parts of the world as well as

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<v Speaker 1>outside of it. Today's episode was written by Mark Mancini

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<v Speaker 1>and produced by Tristan McNeil. For more on this and

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<v Speaker 1>lots of other lively topics, visit our home planet, how

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<v Speaker 1>Stuff Works dot com.