How Ants Respond to Predators Suggests Superorganism Capabilities

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 When you accidentally pick up a burning hot plate of dinner from the microwave, despite the ensuing stream of expletives, you are unlikely to sustain a severe burn. While a few cells in your hand may die, the rest of your cells coordinate to protect you by letting go of the plate and yanking your hand out harm’s way. With even less swearing, some ant colonies can achieve a similar level of coordination—losses from different parts of the colony can trigger the rest to retreat from danger.
 
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 Entomologist Thomas O’Shea-Wheller studies these behaviors in colonies of
 
 Temnothorax albipennis
 
 ants in his lab at the University of Bristol. When he simulates predator attacks, he said the ants “are able to communicate the location of where it is happening very precisely,” and thus execute the most effective escape. When attacked outside the nest, they retreat inside, while if attacked from the inside, they jump nest and search for a new home.
 

 To obtain test subjects for his most recent
 <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0141012">
 study
 </a>
 , O’Shea-Wheller and his colleagues head to a quarry several miles out of town and use small straw-like tools to suck ant colonies into test tubes.
 
 T. albipennis
 
 colonies are only a few hundred individuals at most—a relatively manageable size. Back in the lab, they provide each colony with a transparent nest through which they can observe nest maintenance workers as well as scouts running reconnaissance for food and new nesting sites.
 

 However, sometimes the scouts never make it back. O’Shea-Wheller, paintbrush in hand, sweeps them into another container, as though he were a pheasant pecking away at a delicious lunch. Within minutes, the outbound stream slows to a trickle and stops.
 

 Related ant species do this by monitoring how frequently those in the nest are jostled by returning scouts. According to Oxford zoologist Takao Sasaki, if nobody bumps into them on the way in, the colony ceases sending out scouts, thereby avoiding a waiting predator. Sasaki’s colleague at Stanford, Deborah Gordon, demonstrated this by removing scouts but mimicking their return by dropping small glass beads into the colony entrances. Those colonies were tricked—they continued to send out scouts.
 

 But lock-down isn’t the ants’ only strategy. Several of O’Shea-Wheller’s synthetic nests have holes through which he can slip a paintbrush, simulating a smaller predator in the nest. The moment an ant detects the brush, it will become “very excited, kind of run around making a commotion,” O’Shea-Wheller said. Neighboring ants respond in kind; some may even grab a brush bristle in their tiny jaws and try to sting it. In a matter of seconds, the “whole colony will explode into activity.” The ants likely sound the alarm by releasing a pheromone called dimethalpyrazine, which other ants can detect and release themselves, activating the entire colony via a chain reaction. Workers pick up the defenseless larvae and evacuate. Over the next hour or two, the entire colony migrates to another synthetic nest laid out about a foot away.
 

 To O’Shea-Wheller, the ability to coordinate different responses to these two types of attacks is part of what makes them a super-organism—a disconnected but unified living thing—rather than just a group of individuals. The distinction is clear “if you were to compare to something we wouldn’t call a superorganism, like wildebeests,” O’Shea-Wheller said. “If they’re being attacked by predators, they’re quite uncoordinated.”
 

 But Sasaki, is not so sure. While he loves the study, he questions whether the spatial coordination is actually unique. If he were to try a similar experiment on a flock of starlings, removing individuals from the periphery and the center, he said. “It’s plausible I’d find similar results…but I wouldn’t call them a superorganism.”
 

 To him, it’s that “the goals are different,” he said. “Individual ants have goals to achieve collective tasks…they’re really altruistic. Some ants go outside even though it’s really risky…for pigeons, it’s selfishness.”
 

 “But it’s tricky,” Sasaki said, acknowledging that the distinction between a group of organisms and a super-organism may be philosophical.
 
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 Photo credits:
 <a href="https://commons.wikimedia.org/wiki/File:Communication_in_bulldog_ants_(Myrmecia_nigriscapa)_Sydney,_Australia.jpeg">
 Animalparty/Wikimedia Commons (CC BY)
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Can Warning Labels Help Stop Climate Change?

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 North Vancouver, British Columbia, is undertaking a small experiment to limit its greenhouse gas emissions, one that shares more with the anti-smoking movement than other environmental initiatives.
 

 It is the first city in the world to require all gas pumps to have warning labels. Many compare this to the warning labels on cigarette packages—rotting teeth, tar filled lungs, children inhaling second-hand smoke—a knowledge campaign often credited with drastically reducing smoking rates across America and Europe. But these labels and their champions are a little different.
 
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<figcaption>Gas pumps in North Vancouver, Canada, will have to carry warning labels about the fuel's health and climate effects.
 
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 “Putting warning labels on gas pumps seemed…cool and daring,” said Emily Kelsall, the 17-year-old who put the bylaw in motion. “We all acknowledge that climate change is a problem, but it sort of exists outside our realm of consciousness. This puts it in our face as something imminent and important.”
 

 Kelsall first heard of the concept in a radio interview while being driven to school. Captivated, she decided to promote the idea to several local municipalities, including the city of North Vancouver where 45% of greenhouse gas emissions come from transportation. Last June, this one woman delegation asked the City of North Vancouver to require these labels on all gas nozzles in the municipality. As of November 16, the city council unanimously passed the proposal into law, and council staff are starting their design process.
 

 Labels like these are a quintessential “nudge”—a method of influencing choices without restricting them. For centuries, salesmen, artists, lawyers, writers, parents, and children have nudged instinctually, leveraging what they know of human nature to affect other people’s behaviors. But within the last few decades, the practice has become more intentional. Popularized in the 2006 bestselling book,
 
 Nudge
 
 , behavioral scientists and economists are systematically and quantitatively studying what makes nudges affective. Because they can be so influential, governments are nudging people to do all sorts of things: vote, save up for retirement, use less water, pay their taxes on time, exercise and now, reduce their gasoline use.
 

 Rob Shirkey, executive of the non-profit Our Horizon, first came up with idea of labeling gas nozzles in the summer of 2011. He was stuck in bumper-to-bumper rush hour on the 401, a super-highway in Toronto eighteen lanes wide at some points, listening to a radio discussion of the Deep Water Horizon oil spill. “There I was…thousands of cars in eyesight just burning fossil fuels,” Shirkey said. “Every single caller, every single pundit and every single radio person is saying ‘Shame on BP! Shame on BP! Shame on BP!’ Meanwhile, I think to myself, you know, if I put on my X-ray goggles I can see the gas tanks…we’re all just sitting on top of gasoline that needed to be refined from oil,” he said. “There’s this complete and utter disconnect.”
 
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 The disconnect is not limited to huge oil spills. “At the end of the day, we do know that burning fossil fuels impacts climate change in a negative way,” said North Vancouver city councilor Linda Buchanan. “So let’s make that link.”
 

 Our Horizon’s provocative warning labels try to do just that. Shirkey tried to bolster his design with behavioral research, such as the European Union’s meta-analyses of cigarette label campaigns. These studies examine many aspects of warning labels including the use of images, colored text, and negative messaging.
 

 But psychologist Marc Green, a warning labels specialist, is skeptical of their effectiveness. “With a lot of those studies, it’s impossible to isolate the effects of the labels from the larger campaign,” Green said. Furthermore, he thinks the content of warnings is not nearly as impactful as the viewers’ beliefs. “This is the great Catch-22 of warnings,” Green said. “If you don’t believe that something is dangerous then you won’t pay attention to warnings…which is ironic!”
 

 People’s beliefs are also at the forefront of Buchanan’s mind. “There are some concerns that if the messages were so negative that it would perhaps make them angry and perhaps turn them off the whole issue.” Caroline Jackson, the city’s environmental sustainability manager overseeing the label design process, agreed. “If you provide only a negative message, that can work for certain segments of a population…but it can actually alienate others,” Jackson said.
 

 Green agreed that ineffective warnings can actively turn people off the issue. “Warnings aren’t for free,” Green said. “It poisons the well…and contributes to people’s general disregard for warnings.”
 

 Jackson, therefore, plans to couple the warning messages with suggestions for what people can do to reduce their gas use: check their tire pressure, carpool, use public transit (which Jackson has already labored hard to improve). “We want people to join us and see that they can make a difference,” Jackson said. For emphasis, Jackson actually calls them “Information Labels” rather than “Warning Labels.”
 

 Information is a powerful part of any nudge, according to series of studies out of the Swiss Federal Institute of Technology in Zurich. Verena Tiefenbeck’s research has shaped a product to reduce the second most energy intensive behavior in the typical home—water heating. After several years of test runs, data collection and design modification, Tiefenbeck has optimized her nudge, a small water tracker that attaches to a shower head.
 

 “In the shower, people are just enjoying the warm water on their skin,” Tiefenbeck said. Energy expenses, water bills, and climate are “so far from their minds.” But the meter, powered by the flow of water, confronts the person with an ever increasing tally of how much water they are using as well as the temperature of that water.
 

 This increases what psychologists call the “salience” of the financial and environmental consequences in real time. And real time feedback is essential. In Tiefenbeck’s study, control group meters that only delivered the information after the shower was completed had a much lower effect on the water consumption.
 

 The numbers are also salient because they’re put into understandable terms. “At least people can relate to gallons or liters,” Tiefenbeck said. Alternative models that reported the information in more abstract terms like carbon dioxide emissions or kilowatt hours did not have as powerful an effect. This didn’t surprise Tiefenbeck. “My friends don’t spend their day chasing after kilowatts,” she said.
 

 But in the land of nudges, the distinction between information and warning often blurs. One Tiefenbeck’s models depicted a little polar bear whose iceberg slowly shrinks over the course of a long shower, which Tiefenbeck’s subjects liked so much the company made the bear a permanent feature. This final design reduces the average household energy consumption by 22%, according to her most recent studies.
 

 Do the effects last, though? In Green’s experience, people often get warning fatigue. “Show them a warning now, and within a few months they won’t even see it anymore,” he said.
 

 Tiefenbeck’s meter has so far sustained it’s affect over several years of data collection in the Netherlands. More studies are currently underway in Singapore and Korea.
 

 Caroline Jackson has a plan to combat warning fatigue among North Vancouver drivers. Her team plans to make many label designs which can rotate in and out. “We want them to be fresh,” Jackson said.
 

 To Tiefenbeck though, no approach is certain. When asked what makes an environmental nudge successful, she responded simply: “Field studies.”
 
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 Photo credits:
 <a href="https://www.flickr.com/photos/booleansplit/20342417494/">
 Robert S. Donovan/Flickr (CC BY-NC)
 </a>
 , Our Horizon

Medical Research Has a Sex Problem

The lack of female subjects in medical research has life-altering health consequences for women.

Leaky Blood Vessels Could Help Prevent Alzheimer's

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 For Alzheimer’s patients and their care providers, amyloid beta is memory enemy number one. While all brains make this small molecule, the brains of Alzheimer’s patients seem unable to get rid of it. However, James Keaney, a postdoc at Trinity College in Dublin, can coax amyloid beta out of a mouse’s brain through its blood vessels.
 

 That’s no easy task—in mammals, the brain’s blood vessels “have developed an extra protection, what we call the blood brain barrier,” Keaney said. Normally, the barrier only lets desirable substances through and keeps intruders out of the delicate brain tissue.
 
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<figcaption>An illustration of how amyloid beta may escape through gaps in the brain's blood vessels.
 
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 But he can make the barrier leakier if he lowers the levels of two proteins: claudin-5 and occludin, which are key components of the tight junctions that stitch individual barrier cells into a single, unified wall. After lowering the levels of claudin-5 and occludin in the tight junctions of mice, Keaney could detect even higher levels of amyloid beta in their blood, indicating an even leakier blood brain barrier.
 

 Keaney’s team also found that healthy brains might use the same strategy to prevent a build-up of amyloid beta. When they exposed blood brain barrier cells in a petri dish to high levels of amyloid beta, the cells decreased their claudin-5 and occludin levels by themselves, implying that healthy mouse brains might temporarily increase the leakiness of their barrier when there is too much amyloid beta. If mouse brains do this, ours may, too.
 
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<figcaption>A cortical microvessel from the brain of a Rhesus macaque, an ape closely related to humans
 
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 In fact, Keaney also has some evidence to suggest that our brains use a similar mechanism. Since experimenting on live humans’ brains is too risky, he conducted autopsies on deceased Alzheimer’s patients. As predicted, the levels of claudin-5 and occludin were very low, suggesting that their brains were “trying” to clear the excess amyloid beta, he said. But there was still so much amyloid beta that the toxin had formed large conglomerations around the vessels called plaques—a telltale sign of advanced Alzheimer’s.
 

 Why didn’t the leak-it-out mechanism work for these people? “Plaques are really sticky,” Keaney said. “They can’t move and they’re difficult to break up. At this late stage in Alzheimer’s, it’s too large to pass between cells anymore.”
 

 If this line of research is to lead to a treatment, scientists must also find ways to lower the levels of claudin-5 and occludin early in life before the amyloid beta accumulates. Even if they do find a way, such a dramatic change to brain security is always risky. That security is there for a reason, Keaney said. “You almost never hear of someone getting a brain infection.”
 

 Such treatments would also require a better understanding of the various states of the amyloid beta molecule itself, which is cut “from a larger precursor protein that exists in the membranes of all neurons,” Keaney said. This freshly cut amyloid beta can then transition into other forms, one of them being plaques.
 

 But a 2013 study in
 
 Nature
 
 by researchers at Korea University, demonstrated that brain cells in culture were largely unharmed by amyloid beta plaques. An MIT post-doc (who wishes to stay anonymous) pointed out that there is “accumulating evidence that the short-lived transition from monomer to plaque is the neurotoxic species,” rather than the plaque form itself. Researchers must identify what forms of amyloid beta are causing the neurological damage associated with Alzheimer’s in order to know if Keaney and his team are on the path to a viable treatment.
 
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 Image credits:
 <a href="https://commons.wikimedia.org/wiki/File:Brain_Microvessel.tif">
 Nathan S. Ivey and Andrew MacLean/Wikimedia Commons (CC BY-SA)
 </a>
 , Eben Bein

Eben Bein

Articles

How Ants Respond to Predators Suggests Superorganism Capabilities

Can Warning Labels Help Stop Climate Change?

Medical Research Has a Sex Problem

Leaky Blood Vessels Could Help Prevent Alzheimer's

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