Bacteria that have no friends don’t get sad; they get weird. When E. coli cells sense fewer other bacteria around them, their DNA starts to mutate at a faster rate. That’s bad news for humans and our antibiotics. But if we can make bacteria feel less alone, we might be able to slow down their destructive rampages.
“Personally, I find it pretty surprising that this hasn’t been pinned down before,” says Christopher Knight, a lecturer in the University of Manchester’s Faculty of Life Sciences. The discovery didn’t take any kind of high-tech tests. Lead author Rok Krasovec, a member of Knight’s research group, simply grew E. coli bacteria in varying amounts of food. Cells with more food went through a greater number of generations every day, creating denser populations; those with less food multiplied more slowly.
Then Krasovec treated the cells with rifampicin, an antibiotic that’s used for TB. Read More
Going to the bottom of the ocean isn’t such a big deal. Sure, James Cameron generated a lot of fuss last year with his record-breaking descent into the Mariana Trench—but Uncle Ben has been to the deep sea without even using a sub. Yes, that picture shows a packet of Uncle Ben’s microwaveable rice a kilometer deep in the Atlantic Ocean. It’s one of the items an international group of scientists found in their detailed inventory of underwater garbage.
The scientists pooled data from 588 different surveys of the seafloor, covering 32 European sites. The studies had taken place in the Atlantic and Arctic Oceans and the Mediterranean Sea between 1999 and 2011. Some were surveys by remotely operated vehicles, scanning the seabed with video cameras. Others were brute-force sweeps with trawling nets. From all this, a few patterns emerged. Read More
There may not be an “I” in “team” but there are two in “championship,” and basketball players going after one of those play more selfishly. That’s what researchers found when they analyzed nine seasons’ worth of NBA games. Players who hog the ball might have the right idea—every shot they make leads to a higher salary in the next year.
The study was undertaken by two management professors, Eric Uhlmann of HEC Paris and Christopher Barnes of the University of Washington’s Foster School of Business. They crunched numbers for all 30 NBA teams between 2004 and 2013, from the regular season through the playoffs, which every team except one* reached at some point.
For each game, they measured “cooperative play” by calculating the ratio of assists to baskets made. Read More
Are you intimidated by this bird? Would you be if it destroyed all your unborn children?
Some species of cuckoo and other birds are “brood parasites.” This means that instead of raising their own young, they sneak their eggs into other birds’ nests and let the adoptive parents do all the work. If you watch these parents taking care of hulking nestlings that are clearly a different species from their own young (and sometimes bully their adoptive siblings out of the nest), it’s hard not to see the parents as suckers. But there’s evidence for another possibility: that adoptive parents accept baby cuckoos into their nests because they fear violent retaliation if they don’t.
The “mafia hypothesis” is based on scientists’ observations that great spotted cuckoos (above) and brown-headed cowbirds (another brood parasite) can retaliate against birds that oust their eggs. If a host parent tosses a cuckoo or cowbird egg of out its nest, the cuckoo or cowbird parent may return and destroy every other egg that bird has laid. Read More
No matter how rough a winter you think you had, it was nothing compared to what a wood frog survives every year. Some of these little amphibians are still waiting for spring, when they’ll thaw out and turn from frog-shaped blocks of ice back into animals. Recently, scientists took a close look at wood frogs living deep in the Alaskan woods and learned that they’re even more impressive than we’d imagined.
Wood frogs (Lithobates sylvaticus) are known for their skill—more like a superpower, really, in the animal world—of freezing solid for the winter. Forget migrating to warmer climes or hibernating in caves: they hunker down and let the ice take them. It crackles through their thumb-sized brown bodies, freezing the skin, the blood, the brain. This would kill most animals easily. But come spring, the wood frog reanimates itself and hops off to breed like nothing ever happened.
Most research on this species has looked at frogs from the Midwest or southern Canada. It’s been reported that temperatures below –7°Celsius (about 20°F) can kill the frogs. A laboratory study found that being frozen for more than 2 months is often fatal. Yet the frogs’ range extends into the Arctic Circle in Alaska and Canada. Even below the Arctic Circle, their habitat in Alaska can remain below freezing for half the year, and temperatures can reach –20°C.
Does winter here wipe out large numbers of wood frogs—or are they hardier than we think? Read More
(This post was first published in January 2014.)
Lying to your doctor is encouraged in one situation: when your doctor is a student and you’re an actor asked to portray a certain condition. My friend Amy Savage does this for work. In between fake symptom bouts, I asked her to write a guest post sharing what she’s learned from being poked for practice.
Have you ever been asked to “please dislocate your left breast,” or if you “have noticed any hairs growing in places you normally wouldn’t have hairs”? Or maybe someone told you to “have a nice day” after your spouse just passed away or you’d received a cancer diagnosis. Not only do I hear things like this from time to time at my job, but I have grown to expect them.
I have been working for several months as a so-called standardized patient. The local medical school runs an excellent program that lets students conduct histories and physical exams in a simulated, standardized setting. This means I (and many others) pad around in rubberized socks and breezy hospital gowns and feign myriad diseases, syndromes, conditions, and (sometimes nasty) habits. It also means I overuse hand sanitizer and have many strangers listen to my heart, palpate my abdomen, and poke me with a broken wooden Q-tip to test my sensation. One time I even let someone stick their gloved hand in my mouth and squeeze my tongue a little. Read More
Siri doesn’t need your love (sorry). But she does need your trust. At least, she does if you’re going to use her in the way Apple intends. For us to make artificially intelligent technologies like smartphones and self-driving cars a part our routines, we have to be willing to turn over important parts of our lives to them—like our calendars, or our actual lives. Now a study suggests that having a voice and a name is all it takes for a computer to gain that trust.
Adam Waytz, a psychologist at Northwestern University’s Kellogg School of Management, tested people’s trust of technology using a driving simulator named Iris. (Yes, as in “Siri” backward. It was, Waytz says, “the idea of my much cleverer co-author Nick Epley” at the University of Chicago.) Iris’s voice was provided by their colleague Heather Caruso, who happens to do a good computer impression. But, Waytz adds, “I would be interested in testing whether male versus female voices might produce different effects.”
Waytz recruited 100 adults to take the driving simulator for a spin. One group of them used the simulator on a normal setting, driving it just like a real car. For another group, the simulator had autonomous (self-driving) features that they could turn on by pressing buttons on the steering wheel. The final group of subjects was introduced to the simulator as “Iris.” Its self-driving features were the same as for the second group of subjects, but now Iris spoke to subjects directly, giving explanations that had come from an experimenter in the other group. (“Hello, I’m Iris. I can control the gas, brakes, and steering.”) Read More
Before they become butterflies, some caterpillars transform themselves into ants. Rather than living out in the open and braving predators while they grow up, these caterpillars sneak into ant nests for free food and lodging—or they just eat the ants. Either way, scientists have found, part of the caterpillars’ disguise involves mimicking the sounds of an ant queen. When worker ants hear this tune, they drop everything to tend to the mooching invaders.
At the beginning of its life, a caterpillar of the genus Maculinea hangs out on its favorite plant and munches away, like any other future butterfly. Its food plants are within the foraging grounds of Myrmica ants, the caterpillar’s targets. Once it finishes growing, the caterpillar waits until an evening between 6 and 8 PM—prime foraging time for the ants—then lets go of its perch and falls to the ground. There, it waits.
When a Myrmica ant that’s out searching for food stumbles across the caterpillar, it stops and feels it with its antennae. This assessment may take only a few seconds, or may be an hours-long “adoption ritual,” explains University of Turin biologist Luca P. Casacci. Then the ant picks up the giant baby (“Whoops, how did one of our larvae get out here?”) and carries it back to the ant nest.
How the caterpillar takes advantage of its new home depends on its species. Read More
In the fight for attention from researchers, there are winners and there are civets.
That’s what researchers found when they analyzed almost 16,500 published papers about animals from walruses to weasels. They saw clear trends in which animals are the most popular to study. And it matters because the most popular animals aren’t necessarily the ones most in need of attention.
Zoe Brooke, a researcher at the Zoological Society of London, and her coauthors looked at every peer-reviewed paper they could find that was published between 1900 and 2010 about an animal in the order Carnivora. This is a set of 286 mammal species that all—as their name suggests—eat meat, at least sometimes. Medical papers that used animals to model a disease were excluded (sorry, lab mice). Papers on pets were also left out, though feral cats and dogs were fair game.
Winners: Big Guys
There are 15 families within Carnivora. Some of those families contain many more species than others, so the authors ranked the families by the average number of published papers per species. Bears (family Ursidae) crushed the competition, averaging more than 250 papers per species. Read More
If your parents ever groaned that you and your siblings were aging them rapidly with your bickering or loud music, they may have been right—especially if they were jackdaws. Scientists who artificially increased or decreased the size of these birds’ broods found that extra-large families make parents die sooner.
One theory of aging says that it comes from accumulated damage to a body’s cells, and that animals have a limited amount of resources to spend fixing that damage. Using more resources on something like having and raising offspring may leave an animal with a smaller reserve for keeping its cells in good shape. This means reproducing might make it age sooner.
Some long-term studies of wild animals have found evidence that this is true. But, writes Jelle Boonekamp, a biologist at the University of Groningen in the Netherlands, these studies compared animals that naturally had larger or smaller numbers of young. So there might have been an unseen third variable at work—some trait that gives parents more young while also shortening their lives.
To address this problem, Boonekamp and his coauthors stole babies from some birds and tricked others into adopting them. Read More