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5 Strange Microbes (and 1 Bonus Organism)

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Sergio Carvalho via Flickr // CC BY-NC-ND 2.0

The world is teeming with life, and we're always discovering new species—including some that stretch the limits of how we view and classify biological life forms. Here are a few that clearly don't play by the rules.

1. BDELLOID ROTIFERS

Diego Fontaneto via Wikimedia Commons // CC BY 2.5

 
Bdelloid rotifers are microscopic superstars inside a drop of water. These tiny transparent animals—which can be found all over the world (even Antarctica!)—are masters of survival and reproduction. When water becomes scarce, they dry up like brine shrimp, surviving for years completely desiccated. When water returns, they rehydrate themselves and continue on as good as new. Rotifers are all female and reproduce asexually, laying eggs that don't need to be fertilized and are essentially clones of themselves. While they're not the only animal that doesn't need a member of the opposite sex to reproduce, they're more successful than others: Bdelloid rotifers have evolved into 450 species. How can a creature evolve if it's only producing clones? Random mutations would produce changes, but cannot explain the rotifers' 80-million-year survival and successful speciation.

The secret to rotifers' evolution is that they steal genes from other living things. DNA analysis of bdelloid rotifers shows that about 10 percent of their genes come from bacteria, fungi, and plants. How does that happen? It turns out that bdelloid rotifers are also masters at surviving ionizing radiation, which damages DNA. The creatures are able to repair their own DNA, but can incorporate new genes (from the surrounding environment or something they ate) in the repair process. Over time, the new genes are used to adapt to the environment, leading to the evolution of new rotifer species as well as incorporating the necessary genetic material to protect against parasites.

2. EUGLENA

Deuterostome via Wikimedia Commons // CC BY-SA 3.0

 
Euglena is a genus that contains hundreds of species of single-cell organisms that are not plant nor animal nor bacteria, but have features of all three. Most species of Euglena are mixotrophs that power themselves based on environmental conditions. When sunlight is present, for example, Euglena will use it to make food by photosynthesis using chloroplasts, the genes for which may have been taken from engulfed alga sometime in Euglena's evolutionary history. When there is no sunlight, Euglena ingests surrounding substances like an animal to get energy. But what's really amazing about Euglena is that its behavior can be useful to humans. A company in Japan is looking into using some species of Euglena for food and biofuel, and other species might be used to clean the environment as they eat pollutants.

3. TRICHOPLAX ADHAERENS

Bernd Schierwater via Wikimedia Commons // CC BY 4.0

 
Among multicellular animals, the microscopic Trichoplax adhaerens is the master of minimalism. It's so simple, in fact, that for decades it was assumed that it was only a larval stage of another animal. T. adhaerens is comprised of just four types of cells, and is basically two sheets of cells with some more cells in between. It has no organs and no discernible front or back, though it does have a distinct upper and lower side—the organism uses that lower side both to eat and to adhere to surfaces. It can move either by changing shape or by using tiny cilia on its outer layers. It's perhaps not surprising T. adhaerens has an extremely simple genome, too, with 98 million base pairs, compared to over 3 billion for humans. They reproduce by splitting, by budding, or by sexual reproduction. Scientists don't know exactly how they manage the sexual reproduction; organisms have been observed degenerating into eggs, but fertilization is still a mystery.

4. TARDIGRADES

Tardigrades, also called water bears or moss piglets, resemble eight-legged faceless bears, except they're generally a half-millimeter long. Hundreds of species of these tiny animals are found in every kind of environment on earth, but they prefer to be among moss, algae, and lichen. While ocean-based tardigrades are pretty normal, land and fresh water tardigrades are famously hard to kill. If the environment is dry, they dry up too, and go into a dormant state that they emerge from when wet conditions return, even years later. They can survive boiling or freezing temperatures. They can survive in the vacuum of space and in high pressure conditions. They can survive radiation that would kill lesser animals.

In case you want a tardigrade of your own, the International Society of Tardigrade Hunters has instructions for collecting them. A low-power microscope should suffice for observation.

5. GEOGEMMA BAROSSII

A thermal vent. Image Credit: Sergio Carvalho via Flickr // CC BY-NC-ND 2.0

 
A microbe of the Archaea domain, Geogemma barossii is a microbe that likes it hot. This hyperthermophile, sometimes referred to as Strain 121, grows optimally at 220°F, but does just fine at 250°F (or 121°C, hence the name). It doesn't die until temperatures go over 266°F—one of the highest-known temperature tolerances of any living thing. The discovery of G. barossi's heat tolerance in 2003 gave pause to medical specialists when they realized that their sterilization procedures would not kill this microbe. However, Strain 121 cannot grow in the range of a human's body temperature, so it isn't considered infectious. Its normal home is thermal vents in the ocean floor.

BONUS: GROMIA SPHAERICA

The size of a grape, Gromia sphaerica is too big to be a microbe—but this single-celled organism is too cool not to include. This ancient relative of the amoeba lives at the bottom of the ocean, and was first discovered in the Arabian Sea in 2000. Adult specimens can grow to be 1.5 inches in diameter, or as small .019 inches. While a single cell that big is pretty strange, the most remarkable thing about G. sphaerica is the trails they leave behind on the sea floor. They weren't created by the organisms rolling downhill (they can actually move uphill), and they weren't created by ocean currents. Somehow, these big cells moved on their own and are heavy enough to leave a trail behind them. That raises questions about fossil trails from the Precambrian that scientists assumed were left by multicellular animals, but may have been left before multicellular life arose.

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The Elements
9 Essential Facts About Carbon
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iStock / Collage by Jen Pinkowski

How well do you know the periodic table? Our series The Elements explores the fundamental building blocks of the observable universe—and their relevance to your life—one by one.
 
 
It can be glittering and hard. It can be soft and flaky. It can look like a soccer ball. Carbon is the backbone of every living thing—and yet it just might cause the end of life on Earth as we know it. How can a lump of coal and a shining diamond be composed of the same material? Here are eight things you probably didn't know about carbon.

1. IT'S THE "DUCT TAPE OF LIFE."

It's in every living thing, and in quite a few dead ones. "Water may be the solvent of the universe," writes Natalie Angier in her classic introduction to science, The Canon, "but carbon is the duct tape of life." Not only is carbon duct tape, it's one hell of a duct tape. It binds atoms to one another, forming humans, animals, plants and rocks. If we play around with it, we can coax it into plastics, paints, and all kinds of chemicals.

2. IT'S ONE OF THE MOST ABUNDANT ELEMENTS IN THE UNIVERSE.

It sits right at the top of the periodic table, wedged in between boron and nitrogen. Atomic number 6, chemical sign C. Six protons, six neutrons, six electrons. It is the fourth most abundant element in the universe after hydrogen, helium, and oxygen, and 15th in the Earth's crust. While its older cousins hydrogen and helium are believed to have been formed during the tumult of the Big Bang, carbon is thought to stem from a buildup of alpha particles in supernova explosions, a process called supernova nucleosynthesis.

3. IT'S NAMED AFTER COAL.

While humans have known carbon as coal and—after burning—soot for thousands of years, it was Antoine Lavoisier who, in 1772, showed that it was in fact a unique chemical entity. Lavoisier used an instrument that focused the Sun's rays using lenses which had a diameter of about four feet. He used the apparatus, called a solar furnace, to burn a diamond in a glass jar. By analyzing the residue found in the jar, he was able to show that diamond was comprised solely of carbon. Lavoisier first listed it as an element in his textbook Traité Élémentaire de Chimie, published in 1789. The name carbon derives from the French charbon, or coal.

4. IT LOVES TO BOND.

It can form four bonds, which it does with many other elements, creating hundreds of thousands of compounds, some of which we use daily. (Plastics! Drugs! Gasoline!) More importantly, those bonds are both strong and flexible.

5. NEARLY 20 PERCENT OF YOUR BODY IS CARBON.

May Nyman, a professor of inorganic chemistry at Oregon State University in Corvallis, Oregon tells Mental Floss that carbon has an almost unbelievable range. "It makes up all life forms, and in the number of substances it makes, the fats, the sugars, there is a huge diversity," she says. It forms chains and rings, in a process chemists call catenation. Every living thing is built on a backbone of carbon (with nitrogen, hydrogen, oxygen, and other elements). So animals, plants, every living cell, and of course humans are a product of catenation. Our bodies are 18.5 percent carbon, by weight.

And yet it can be inorganic as well, Nyman says. It teams up with oxygen and other substances to form large parts of the inanimate world, like rocks and minerals.

6. WE DISCOVERED TWO NEW FORMS OF IT ONLY RECENTLY.

Carbon is found in four major forms: graphite, diamonds, fullerenes, and graphene. "Structure controls carbon's properties," says Nyman.  Graphite ("the writing stone") is made up of loosely connected sheets of carbon formed like chicken wire. Penciling something in actually is just scratching layers of graphite onto paper. Diamonds, in contrast, are linked three-dimensionally. These exceptionally strong bonds can only be broken by a huge amount of energy. Because diamonds have many of these bonds, it makes them the hardest substance on Earth.

Fullerenes were discovered in 1985 when a group of scientists blasted graphite with a laser and the resulting carbon gas condensed to previously unknown spherical molecules with 60 and 70 atoms. They were named in honor of Buckminster Fuller, the eccentric inventor who famously created geodesic domes with this soccer ball–like composition. Robert Curl, Harold Kroto, and Richard Smalley won the 1996 Nobel Prize in Chemistry for discovering this new form of carbon.

The youngest member of the carbon family is graphene, found by chance in 2004 by Andre Geim and Kostya Novoselov in an impromptu research jam. The scientists used scotch tape—yes, really—to lift carbon sheets one atom thick from a lump of graphite. The new material is extremely thin and strong. The result: the Nobel Prize in Physics in 2010.

7. DIAMONDS AREN'T CALLED "ICE" BECAUSE OF THEIR APPEARANCE.

Diamonds are called "ice" because their ability to transport heat makes them cool to the touch—not because of their look. This makes them ideal for use as heat sinks in microchips. (Synthethic diamonds are mostly used.) Again, diamonds' three-dimensional lattice structure comes into play. Heat is turned into lattice vibrations, which are responsible for diamonds' very high thermal conductivity.

8. IT HELPS US DETERMINE THE AGE OF ARTIFACTS—AND PROVE SOME OF THEM FAKE.

American scientist Willard F. Libby won the Nobel Prize in Chemistry in 1960 for developing a method for dating relics by analyzing the amount of a radioactive subspecies of carbon contained in them. Radiocarbon or C14 dating measures the decay of a radioactive form of carbon, C14, that accumulates in living things. It can be used for objects that are as much as 50,000 years old. Carbon dating help determine the age of Ötzi the Iceman, a 5300-year-old corpse found frozen in the Alps. It also established that Lancelot's Round Table in Winchester Cathedral was made hundreds of years after the supposed Arthurian Age.

9. TOO MUCH OF IT IS CHANGING OUR WORLD.

Carbon dioxide (CO2) is an important part of a gaseous blanket that is wrapped around our planet, making it warm enough to sustain life. But burning fossil fuels—which are built on a carbon backbone—releases more carbon dioxide, which is directly linked to global warming. A number of ways to remove and store carbon dioxide have been proposed, including bioenergy with carbon capture and storage, which involves planting large stands of trees, harvesting and burning them to create electricity, and capturing the CO2 created in the process and storing it underground. Yet another approach that is being discussed is to artificially make oceans more alkaline in order to let them to bind more CO2. Forests are natural carbon sinks, because trees capture CO2 during photosynthesis, but human activity in these forests counteracts and surpasses whatever CO2 capture gains we might get. In short, we don't have a solution yet to the overabundance of C02 we've created in the atmosphere.

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8 Myths About Dead Bodies You Probably Think Are True
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Bodies are weird enough, but it's the dead ones that hold real intrigue. The fact that most of us just don't spend that much time around them means it's hard to separate truth from fiction; corpses have been thought to be responsible for plagues, as well as to carry magic healing properties. Below, some dead body myths that won't give up the ghost—and explanations for the real-life science behind them.

1. HAIR AND NAILS GROW AFTER DEATH.

Corpse under sheet with hand sticking out

Not true! The cell division driving hair and nail growth stops when the body dies and the heart no longer pumps oxygen-filled blood throughout the circulatory system. It does look like things keep growing, though. When a dead body's skin loses hydration, it retracts—and retraction along the nail bed makes it appear as if the nails are getting longer. As for hair, drying skin on the face and head "pulls back towards the skull, making stubble appear more prominent," writes Claudia Hammond for the BBC. "Goosebumps caused by the contraction of the hair muscles can add to the effect."

2. DEAD BODIES ARE DANGEROUS.

There's no science to back up the idea that a dead and decomposing body is harmful to the living just by virtue of its being dead. This might sound obvious, but the belief that disease came from breathing in air infected by corpses was once common.

Miasmatic theory, as it was called, was a widespread belief among members of the medical profession (and the public) in the 19th century. Miasma, an ancient Greek word for "pollution," was the bad air coming from "rotting corpses, the exhalations of other people already infected, sewage, or even rotting vegetation" and was thought to be responsible for the spread of disease. Fortunately, this belief was eventually replaced by germ theory.

3. … AND MULTIPLE DEAD BODIES ARE EXTRA DANGEROUS.

In a publication from the Pan American Health Organization (a division of the World Health Organization), Donna Eberwine explains that the belief that dead bodies spread disease "remains a chronic problem in disaster relief efforts." After natural disasters, there is often a hysteria around dead bodies and a rush to immediately bury them, which distracts relief efforts from more pressing concerns. "The microorganisms that are involved in decomposition are not the kind that cause disease," Eberwine writes. "And most viruses and bacteria that do cause disease cannot survive more than a few hours in a dead body."

There are some exceptions. The level of Ebola virus in dead victims remains high, and their remains should only be handled by people in protective gear (and buried quickly). HIV can live for up to 16 days in a body held under refrigeration, and other blood-borne viruses like hepatitis, along with tuberculosis and gastrointestinal infections, can pose a risk. "The risk of contagion can be minimized with basic precautions and proper hygiene," Eberwine writes.

4. EMBALMING MAKES DEAD BODIES "SAFER."

Egyptian sarcophagus

"Embalming provides no public health benefit," according to the Funeral Consumer's Alliance (a nonprofit focused on affordable death care), citing the Centers for Disease Control and Canadian authorities. While individual morticians might say that a body must be embalmed before viewing, burial, or cremation, the process is generally not legally required. Moreover, since a dead body is usually not in itself harmful, embalming does not make it any safer. On the flip side, embalming chemicals are actually quite toxic, and embalmers must cover their entire body and wear a respirator while working. 

5. DEAD BODIES SIT UP ON THE MEDICAL TABLE.

This horror-movie trope just isn't real. During decomposition, a body might twitch or make small movements and noises due to the gas and waste released by bacteria. A decomposing corpse can definitely move a little, but sitting straight up is just not going to happen.

6. BURYING A BODY WITHOUT A COFFIN OR VAULT MEANS IT WILL CONTAMINATE THE GROUNDWATER.

Nope! Burials usually occur at 3.5 feet below the surface, whereas water can be 75 feet underground. "Mandatory setbacks from known water sources also ensure that surface water is not at risk," the Green Burial Council explains [PDF]. Additionally, because microorganisms living in the soil will break down the chemical compounds that remain in a dead body, we actually give out "more toxic chemicals during a day of living than a whole body will decomposing."

7. CREMAINS ARE "ASH."

Wall of cremation urns

Though we often talk of "scattering ashes," cremains are a little more complicated. Once a body intended for cremation has been burned in what's called a retort, what's left will be put in a cremulator. Sort of like a blender, the cremulator uses ball bearings or rotating blades to pulverize the bones and other remnants into a "grayish, coarse material, like fine gravel," as HowStuffWorks puts it.

8. ALL IN ALL, MAYBE DEATH ISN'T AS SCARY AS WE THINK.

According to psychological scientist Kurt Gray, it's possible that death isn't quite as terrifying as we think it is. Gray studied the responses of death row inmates and terminally ill patients as well as those of people asked to imagine they had untreatable cancer, and found that "while it's natural to fear death in the abstract, the closer one actually gets to it, the more positive he or she becomes," as New York Magazine explains. This may be due to something called the "psychological immune system," a term coined by Harvard psychologist Dan Gilbert in his book Stumbling on Happiness. According to Gray, our psychological immune system is engaged when bad things happen. "So when one is faced with death, all sorts of rationalization and meaning-making processes come in," he told New York Magazine. That may sound like your brain's trying to give you a cop-out, but it's much better than living in terror.

All photos courtesy of iStock.

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