Discovered: Scientists debunk the discovery of new life, blame your friends for your weight fluctuations, a citizen science project finds that bees are disappearing from cities, and scientists teach flies to count.
No new life under the sun. As it turns out, that “new life form” everyone freaked out about back in 2010 might not be so biologically alien after all. A group of researchers led by Felisa Wolfe-Simon made headlines when they announced their discovery of a bacterium dwelling in California’s Mono Lake (pictured above) which they said used arsenic rather than phosphorus as an essential building block in its DNA. This discovery pointed toward the possibility of other forms of life — here on Earth, or beyond. Scientists were naturally skeptical. Many set out to replicate the findings, only to discover that while the microbe can thrive in arsenic-rich environments, it still requires phosphorus. “I think we have now very solid evidence that the metabolism of GFAJ-1 is as dependent on phosphorus, as are all other known forms of organic life,” says Julia Vorholt, a microbiologist at the Federal Institute of Technology in Zurich, Switzerland. Science, the journal that originally published Felisa Wolfe-Simon, et al.’s findings, released two papers refuting the controversial claims this month. But they aren’t going so far as to retract it. “Except in rare cases, corrections, clarifications, or retractions should ideally be initiated by the original research authors,” write the editors of Science. “The scientific process is a self-correcting one as scientists seek to replicate or refute findings put forth in the scholarly literature.” [The Washington Post]
Obesity may be “contagious.” Do you have one of those friends who’s always plying you with food—the kind that shows up to every social gathering with an armful of baked goods in tow? If you’ve ever suspected that they’re the reason you’ve been putting on weight lately, David Shoham and his colleagues Loyola University can confirm what you’ve suspected all along: your friends are making you fat. The researchers studied groups of high school students to determine what effects your circle of friends has on your waistline. They find that friends who are heavier than you may influence you to gain wait. If your friends are thinner than you, they’ll motivate you to shed some pounds—or at least gain less weight. Of course, some of this phenomenon can be attributed to the fact that people tend to befriend those with similar body types. “But even after controlling for this friend-selecting process, there still was a significant link between obesity and a student's circle of friends,” Loyola wrote in its press release. [EurekAlert]
Bees are disappearing from cities. In recent years, scientists have been fretting over the sudden disappearance of bee colonies, and the impact it will have on our food supply. Wanting to get hard data on the bee population in the United States, San Francisco State University biologist Gretchen LeBuhn called upon a citizen scientists to count bees in their neighborhoods. Think of it as a Census for bees, carried out by curious volunteers. The initial numbers are in, and they reveal a steep decline in urban bee populations. The drop-off can be attributed to habitat loss, a phenomenon that occurs when buildings, highways or other features of the urban landscape disrupt bee colonies. Urban community gardens, which are often a haven for bustling bee hives, were one notable exception. “We were surprised that community gardens had such high visitation rates,” LeBuhn said, “but that’s good news because they’re important sources of food production, and we want to make sure they’re getting enough pollinators.” Volunteers contribute to LeBuhn’s project—now the largest single database on bee activity in North America—simply by counting the number of bees that visit a sunflower over two 15-minute intervals per month. [San Francisco State University]
From counting bees to flies that can count. Abstract thinking ranks pretty high on the totem pole of things that supposedly separate humans from animals. Though we now know that our closest biological relatives in the animal kingdom can count in a rudimentary, our ability to do math is often cited as a specifically human trait. But now, thanks to evolutionary geneticists Tristan Long of Wilfrid Laurier University in Waterloo, Canada and William Rice of University of California, Santa Barbara, there's another species that can count: the common fruit fly. Long and Rice effectively taught a generation of flies how to associate sequences of flashing lights with intense shaking, which they only administered on specific numbers of flashes. It took 40 generations for the flies to evolve into this skill. Long says that he'd now like to study "how [the flies’] neuro-architecture has changed." [Nature]
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