This year brought us our first closeup look at Pluto, a new and surprising member of the human family tree, a much-needed influx of research into Ebola and a tempest over the ethics of editing the human genome. But what interesting, important or quirky new science flew under the radar in 2015?
Here is a selection of eight scientific advances you may have missed this year, presented in no particular order:
Kill Switches Could Stop Escaping GMOs
One of the biggest ocean stories of 2015 was the decision by the U.S. Food and Drug Administration to approve genetically engineered salmon for sale and consumption. Although the overwhelming amount of scientific evidence to date agrees that genetically modified organisms (GMOs) are safe to eat, many people are still debating the environmental consequences of introducing GMO crops and livestock into the consumer market. The worry is that an altered creature could get out and breed with its unaltered kin, which could have unforeseen consequences on wild ecosystems.
That’s where “Deadman” and “Passcode” come in. Developed by researchers at Harvard and MIT, these cellular signals were coded into the bacterium Escherichia coli as safeguards against the spread of genetically engineered microbes. If Passcode senses a predetermined change in the surrounding environment, it activates Deadman, which causes the bacterial cells to self-destruct by producing a lethal toxin.
For now, the safeguard only works in bacteria, but the researchers think the same mechanism could be used to design GMO crops that kill themselves if they spread beyond their intended fields. The work appeared in December in Nature Chemical Biology.
New Clues About Maya Daily Life Found Frozen in Ash
The village was abuzz with activity, with many people likely preparing for the annual harvest festival. Then, the volcano looming over the landscape exploded with ash and fire. The abrupt and unexpected catastrophe buried the landscape in up to 17 feet of debris, creating an exceptionally well-preserved record of life, and death, in this ancient town.
This is Ceren, a Maya village in El Salvador that has been called the Pompeii of the New World. Re-discovered in 1978, the long-buried village still holds all kinds of evidence of what Maya activities were like in the year 660, when the volcano effectively froze things in time. Previous excavations have uncovered intensive manioc farming, a community sauna and a notable abundance of jade axes. In the latest finding, published in November in Latin American Antiquity, Payson Sheets of the University of Colorado and his colleagues describe evidence that common people, not a ruling class of elites, were in charge of daily life in the town. That’s in stark contrast to previous evidence of top-down social structures among the Maya.
"This is the first clear window anyone has had on the daily activities and the quality of life of Maya commoners back then," Sheets says in a press release. "At Ceren we found virtually no influence and certainly no control by the elites."
Some Cats Prefer Not to Follow Their Noses
Cats are finicky—the notorious feline habit of doing whatever they want regardless of human concerns is part of their frustrating charm. Based on their behavior and genetics, some experts question whether house cats are even truly domesticated, and that independent spirit has made studying domestic cats much harder than investigating other common pets such as dogs. But tenacious researchers are doing what they can to untangle the feline mind and figure out a little of what motivates our fluffy companions.
In a study appearing online in January 2015 in Applied Animal Behaviour Science, scientists at the U.K.’s University of Lincoln report that individual cats seem to have specific preferences for how they locate their dinner. Most people cracking open a can of cat food might assume that kitty appears magically at your feet based on the sound and smell. Putting a group of cats in a specially designed maze, the U.K. team tested whether cats navigated the labyrinth to receive a tasty treat using either visual or olfactory cues. In most cases, they found that cats showed a stronger preference for sight over smell. But because their test group was relatively small—just six animals—they caution that it’s more likely that sensory preference varies from cat to cat.
"Up until now we really thought that the sense of smell would dominate how cats view their world, but we are now reconsidering this and also the implications of how we manage them,” lead author Evelyn-Rose Elizabeth Mayes says in a press release. For instance, the team says, figuring out specific cats’ preferences may help shelters create more soothing environments for their feline wards.
Mushrooms Are Nature’s Little Rainmakers
Growing in circular fairy rings or oozing psychedelic compounds, mushrooms can be pretty wild. Now scientists believe that they may also be nature’s little rainmakers. Raindrops form in clouds by gathering around microscopic particles of dust and smoke—just like condensation forming on the surface of a glass. But in October, a team of researchers published a paper in PLOS ONE proposing that mushroom spores may actually play a big role in rain, particularly over tropical forests.
Every year, mushroom caps can produce millions of tons of spores—cells that can develop in their own tiny fungi forests. The team found that the sugars these spores emit absorb water, helping drops condense from clouds into rain. Thriving in damp environments, it seems only reasonable that the mushrooms have figured out how to make it rain.
Quantum Spookiness Is the Real Deal
You may not give much thought to the invisible world of quantum mechanics, even though its effects are in use all around you. But physicists have struggled for years to determine how real some of quantum theory’s more bizarre predictions might be. Since the 1960s, one of the strongest pieces of evidence has been a test of quantum weirdness known as Bell’s inequality.
Developed by physicist John Stewart Bell, the theory shows how to test that pairs of electrons are linked by an effect called entanglement, so that one particle instantly displays certain properties when its partner is measured, even if they are separated by vast distances. Albert Einstein famously disagreed, calling entanglement “spooky action at a distance” and saying there must be some other explanation. That’s because entanglement seemed to violate a core part of his otherwise rock-solid theory of relativity: nothing, not even information, can travel faster than light. For decades scientists have tried to run physical tests of the theory, but the experiments always included loopholes that left room for doubt.
In October, though, a team of scientists published a paper in Nature describing the first loophole-free test of Bell’s inequality, and the results show once and for all that yes, the quantum world is a spooky place.
Your GPS May Be Lying to You
Before you start celebrating that run clocked on your fancy new smartwatch, you should know that it may be lying to you. Researchers at the University of Salzburg showed that many GPS gadgets, on average, overestimate distance traveled. In a ground-truth experiment, the team saw overestimates of around 10 percent.
Each GPS measurement has two types of error: interpolation error and measurement error. Interpolation error comes from the need to connect the dots between each sampling point. If the sample points are taken frequently, interpolation error is minimal—imagine a connect-the-dots with 10 versus 100 points. But measurement error comes from the reality that nothing is perfect, and causes can vary from changes in atmospheric conditions to random hardware glitches. That means the measurement error still nags and can add up over time, which the scientists show is the root of the overly flattering results.
But don’t throw in the towel: Not all GPS units are off. Any device that also factors in speed, distance or direction faired much better in the recent truth testing. The team published their results in September in the International Journal of Geographical Information Science.
New Creepy Crawlies Found in Gold Mine Cracks
In the cracks and crevices that snake through the rocks just under a mile under Earth’s surface dwells an unexpected menagerie of creatures. Scientists ventured into the hot caverns of several South African gold mines, some of the deepest mines on Earth. There, they sampled the waters held within fissures in the rock and captured these communities in action with several cameras, some similar to those used in surgeries.
“It is very crowded in some places down under,” researcher Gaetan Borgonie says in a press release. “It’s a veritable zoo!”
The team identified several new nematode worms, Platyhelminthes, rotifera, annelida and arthropoda thriving in waters that had been trapped beneath the surface for up to 12,300 years. Numerous adaptations allow them to flourish in this hot, high-pressure, low-oxygen environment. The researchers published their findings in November in the journal Nature Communications.
The Caribbean Hosts a Weird New Type of Hydrothermal Vent
Hydrothermal vent systems are unlike any other place on Earth, teeming with unusual creatures that feed off the mineral-rich waters that pipe from rifts in the ocean floor. Hydrothermal vents typically form where Earth’s ever-shifting plates pull apart, called spreading centers. Seawater contacts the broiling magma exposed at these seams, heating up and dissolving minerals in the surrounding rock. Like the hot-water jet of the Old Faithful geyser in Yellowstone National Park, water at hydrothermal vents shoots up through the rift, cooling and depositing the dissolved minerals.
In 2010 scientists discovered the Von Damm Vent Field in the Caribbean. But until now, they didn’t know how special their find truly was. The vent system turns out to be a whole new type of hydrothermal vent, researchers report earlier this year in the Journal Nature Communications. Unlike most vents, which rest directly on the spreading center, this new system dubbed the Von Damm Vent Field sits on newly exposed rock still hot from Earth’s interior.
Though the life flourishing at this new system is similar to creatures found along the Mid-Atlantic Ridge, the chemistry is entirely different. The vent’s chimneys are made of the mineral talc—the same stuff in talcum powder. This systems also pumps out massive amounts of heat, around 500 megawatts, which is similar to the energy generated by a commercial power plant. The unexpected placement of this exciting new system suggests that many more may hide in the ocean depths.