Extremophiles: Life on the Edge

The possibility of life on Mars and other planets and moons has been debated for as long as we have known about those planets. Now that water has been found on the Mars, that possibility is more believable than ever. Sure, conditions are fierce on Mars, but research here on planet Earth reveals that life forms can be tough. In fact, wherever it was once thought that no life could exist, more and more organisms are being found that not only live, but thrive and evolve.

Hot Springs

The boiling waters of Yellowstone National Park and other extreme thermal environments have species of thermophiles, or organisms that thrive in temperatures that would kill most living things. These thermophiles have specialized enzymes that keep their DNA from unraveling the way other life forms would. Chemicals from various thermophile species are used for a range of biochemical applications, such as DNA fingerprinting technology. Image by Flickr user v1ctory_1s_m1ne.

The Dead Sea

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The Dead Sea has such a high saline content that pillars of salt form on its banks. Yet Halobacterium salinarum lives in its waters. Halobacterium is one of the most ancient of microbes, and depends more on light for survival than on oxygen. It adjusts its own needs according to the available light and oxygen. Image by Flickr user CharlesFred.

Toxic Sludge

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A copper mine in Montana was abandoned in 1983. As water filled the remaining hole known as the Berkeley Pit, minerals and metals leeched out and made it extremely acidic and poisonous. No fish or plants survived in the toxic water. It was thought to be completely dead until 1995 when a scientist recovered a slime that contained Euglena mutabilis, This protozoan manipulated its immediate environment to make it more livable! Researchers eventually found over 160 different species of microorganisms in the polluted water, some of which are being studied for use in cancer treatment. There is hope that Euglena mutabilis will eventually clean up the toxic water. Image by Linda Amaral Zettler and David Patterson.

Beneath the Great Lakes

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Sinkholes deep beneath the Great Lakes have a very different chemical makeup from the water above. These pockets are filled with salt, acid, and sulfur, but have purple cyanobacteria that use sulfur instead of oxygen for photosynthesis. Other species that live too deep for sunlight to penetrate live on sulfur without photosynthesis.

Sea Floor Volcanos

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In the depths of the Pacific ocean, volcanic vents support life too far down to take advantage of any sunlight at all. Tubeworms and giant clams thrive in volcanic environments by feeding on smaller species that survive only on chemicals without the advantage of photosynthesis. Image credit: NOAA.

High-altitude Volcanos

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The Socompa volcano is 20,000 feet high in the Andes mountains. Conditions there include little oxygen, lack of water, ultraviolet radiation, and methane. But scientists have found moss, algae, and over a hundred species of bacteria living in the shadow of Socompa. The area has been compared to Mars in its ability to sustain life.

In the Clouds

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Bacteria even live in the clouds! These microbes act as particles that ice form around and fall as snow or rain. They are called biological ice nucleators. Nucleators are found in plants and soil and are thought to ride on pollen as it is blown into the atmosphere. The part of the bacterial life cycle spent on vegetation may sustain an ice nucleator during its ride in the clouds, and the cloud seeding may be a mechanism for spreading it to distant parts of the earth.

Space

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No look at extremophiles would be complete without tardigrades, or water bears. These tiny animals are found in various extreme conditions on earth. They can survive hot and cold temperatures, radiation, lack of food and water, and even in a vacuum. The European Space Agency sent tardigrades into orbit in 2008, where they were exposed to cosmic radiation, solar radiation, and vacuum pressure. The space tardigrades were in a dormant state during the flight, which means their metabolism was slowed down considerably -a method they use to weather extreme conditions on earth. After returning from their adventure, they lived and even reproduced! Image by Flickr user Goldstein lab - tardigrades.

Beneath Antarctica?

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Two miles beneath the ice of Vostok Research Station in Antarctica, a huge freshwater lake has been isolated from the rest of the world for millions of years. The water is below freezing temperature, but stays liquid because of the pressure from the ice above. Researchers have not yet broken through to the water, but samples of ice just above the lake reveal the presence of microbe fossils. The lake is saturated with oxygen due to the temperature and pressure, and has been compared with the environments of Jupiter's moon Europa and Saturn's moon Enceladus. There are plans to send down a probe called a cryobot, but extreme care will be taken to preserve the pristine conditions of the isolated lake.

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NASA Has a Plan to Stop the Next Asteroid That Threatens Life on Earth
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An asteroid colliding catastrophically with Earth within your lifetime is unlikely, but not out of the question. According to NASA, objects large enough to threaten civilization hit the planet once every few million years or so. Fortunately, NASA has a plan for dealing with the next big one when it does arrive, Forbes reports.

According to the National Near-Earth Object Preparedness Strategy and Action Plan [PDF] released by the White House on June 21, there are a few ways to handle an asteroid. The first is using a gravity tractor to pull it from its collision course. It may sound like something out of science fiction, but a gravity tractor would simply be a large spacecraft flying beside the asteroid and using its gravitational pull to nudge it one way or the other.

Another option would be to fly the spacecraft straight into the asteroid: The impact would hopefully be enough to alter the object's speed and trajectory. And if the asteroid is too massive to be stopped by a spacecraft, the final option is to go nuclear. A vehicle carrying a nuclear device would be launched at the space rock with the goal of either sending it in a different direction or breaking it up into smaller pieces.

Around 2021, NASA will test its plan to deflect an asteroid using a spacecraft, but even the most foolproof defense strategy will be worthless if we don’t see the asteroid coming. For that reason, the U.S. government will also be working on improving Near-Earth Object (NEO) detection, the technology NASA uses to track asteroids. About 1500 NEOs are already detected each year, and thankfully, most of them go completely unnoticed by the public.

[h/t Forbes]

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10 Scientific Benefits of Being a Dog Owner
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The bickering between cat people and dog people is ongoing and vicious, but in the end, we're all better off for loving a pet. But if anyone tries to poo-poo your pooch, know that there are some scientific reasons that they're man's best friend.

1. YOU GET SICK LESS OFTEN.

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If cleaning commercials are to be believed, humanity is in the midst of a war against germs—and we shouldn't stop until every single one is dead. In reality, the amount of disinfecting we do is making us sicker; since our bodies are exposed to a less diverse mix of germs, our entire microbiome is messed up. Fortunately, dogs are covered in germs! Having a dog in the house means more diverse bacteria enters the home and gets inside the occupants (one study found "dog-related biodiversity" is especially high on pillowcases). In turn, people with dogs seem to get ill less frequently and less severely than people—especially children—with cats or no pets.

2. YOU'RE MORE RESISTANT TO ALLERGIES.

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While dog dander can be a trigger for people with allergies, growing up in a house with a dog makes children less likely to develop allergies over the course of their lives. And the benefits can start during gestation; a 2017 study published in the journal Microbiome found that a bacterial exchange happened between women who lived with pets (largely dogs) during pregnancy and their children, regardless of type of birth or whether the child was breastfed, and even if the pet was not in the home after the birth of the child. Those children tested had two bacteria, Ruminococcus and Oscillospira, that reduce the risk of common allergies, asthma, and obesity, and they were less likely to develop eczema.

3. YOU'LL HAVE BETTER HEART HEALTH.

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Everything about owning a dog seems to lend itself to better heart health. Just the act of petting a dog lowers heart rate and blood pressure. A 2017 Chinese study found a link between dog ownership and reduced risk of coronary artery disease, while other studies show pet owners have slightly lower cholesterol and are more likely to survive a heart attack.

4. YOU GET MORE EXERCISE.

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While other pets have positive effects on your health as well, dogs have the added benefit of needing to be walked and played with numerous times a day. This means that many dog owners are getting 30 minutes of exercise a day, lowering their risk of cardiovascular disease.

5. YOU'LL BE HAPPIER.

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Dog owners are less likely to suffer from depression than non-pet owners. Even for those people who are clinically depressed, having a pet to take care of can help them out of a depressive episode. Since taking care of a dog requires a routine and forces you to stay at least a little active, dog owners are more likely to interact with others and have an increased sense of well-being while tending to their pet. The interaction with and love received from a dog can also help people stay positive. Even the mere act of looking at your pet increases the amount of oxytocin, the "feel good" chemical, in the brain.

6. YOU HAVE A MORE ACTIVE SOCIAL LIFE.

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Not only does dog ownership indirectly tell others that you're trustworthy, your trusty companion can help facilitate friendships and social networks. A 2015 study published in PLOS One found that dogs can be both the catalyst for sparking new relationships and also the means for keeping social networks thriving. One study even showed that those with dogs also had closer and more supportive relationships with the people in their lives.

7. YOUR DOG MIGHT BE A CANCER DETECTOR.

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Your dog could save your life one day: It seems that our canine friends have the ability to smell cancer in the human body. Stories abound of owners whose dogs kept sniffing or licking a mole or lump on their body so they got it checked out, discovering it was cancerous. The anecdotal evidence has been backed up by scientific studies, and some dogs are now trained to detect cancer.

8. YOU'LL BE LESS STRESSED AT WORK.

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The benefits of bringing a dog to work are so increasingly obvious that more companies are catching on. Studies show that people who interact with a pet while working have lower stress levels throughout the day, while people who do not bring a pet see their stress levels increase over time. Dogs in the office also lead to people taking more breaks, to play with or walk the dog, which makes them more energized when they return to work. This, in turn, has been shown to lead to much greater productivity and job satisfaction.

9. YOU CAN FIND OUT MORE ABOUT YOUR PERSONALITY.

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The kind of dog you have says a lot about your personality. A study in England found a very clear correlation between people's personalities and what type of dogs they owned; for example, people who owned toy dogs tended to be more intelligent, while owners of utility dogs like Dalmatians and bulldogs were the most conscientious. Other studies have found that dog owners in general are more outgoing and friendly than cat owners.

10. YOUR KIDS WILL BE MORE EMPATHETIC.

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Though one 2003 study found that there was no link between pet ownership and empathy in a group of children, a 2017 study of 1000 7- to 12-year-olds found that pet attachment of any kind encouraged compassion and positive attitudes toward animals, which promoted better well-being for both the child and the pet. Children with dogs scored the highest for pet attachment, and the study notes that "dogs may help children to regulate their emotions because they can trigger and respond to a child's attachment related behavior." And, of course, only one pet will happily play fetch with a toddler.

A version of this story originally ran in 2015.

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