The evolution of beer yeasts, seedy pants and vampire bat venom-turned medicine

Beer yeasts: Researchers at Lund University in Sweden tracked the history of two yeasts—Saccharomyces cerevisiae and Dekkera bruxellensis—used in alcohol fermentation to pinpoint their role in ethanol production. They found that, around 150 million years ago, competition with other microbes, and the overall increase in sugar-rich fruits, encouraged the yeasts to withstand high ethanol concentrations—an adaptation that would allow them to survive in places other microbes could not. “Now, scientists are closing in on just how and why yeast evolved to [ferment sugars into alcohol],” wrote John Roach in an MSNBC article. “No, it wasn’t to get humans drunk.” Read more at “The why of yeast’s buzz-giving ways” or the press release “Wine yeasts reveal prehistoric microbial world.” Camouflaged cuttlefish: “Cuttlefish are masters of camouflage. Like their relatives, the squid and the octopus, cuttlefish can change the colour of their skin to perfectly match a bed of pebbles, a clump of algae, or a black-and-white chessboard,” wrote Ed Yong of Not Exactly Rocket Science (see below video of previous research). Alexandra Barbosa from the University of Porto found that cuttlefish use visual cues to alter their appendages as well. In other words, when the cephalopods were placed against backgrounds of various striped patterns, they adjusted their tentacles to match the pattern that they saw. Read more and see photos at “Pocket Science – will all camouflaged cuttlefish please raise their tentacles?” Seedy pants: One of the most topical quotes this week—“I wish nature would stop getting it on in my eyeballs”—was uttered by a fellow allergy sufferer. Allergy season is in full force in temperate locales, such as some parts of the U.S. East Coast, as trees flood the air with pollen in the hopes of reaching a female counterpart. There are several ways that pollen travels, such as the wind, but most of us have probably never considered the role of pants in tree pollination. Yes, pants not plants. As quoted in a recent NPR article, “‘Because of his great mobility,’ [British botanist Edward] Salisbury wrote (projecting from his personal data set), ‘man is probably the most active agent—though usually an unconscious one—for [the] external transport of seeds.’” Read more at “Strange Things Happen To Guys Who Wear Pants.” Vampire bat venom: Scientists have tapped vampire bat saliva as a potential medication for treating stroke in humans, and the drug is actually called “Draculin.” It was announced this week that the drug would enter Phase 2 tests. “When vampire bats bite their victims, their saliva releases an enzyme called desmoteplase, or DSPA, into the bloodstream, which causes blood to flow more readily,” wrote Patrick Morgan on Discover’s blog...

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Wet or dry: Butterflies reverse sex roles in extreme seasons

In the case of the African butterfly Bicyclus anynana, females develop ornate wings and court males if they spend the larval stage in a dry, cool environment. The reverse occurs, according to Kathleen Prudic from Yale University and colleagues, when the butterflies are exposed to wetter, warmer environments. “As expected, female Bicyclus anynana in warmer moister conditions that mimic the wet season in the native African range were more likely to mate with males with ornamented wings,” explained a Yale University press release. “However, the roles were reversed in cooler drier climates. Females played the role of suitors and flashed their eye spots to choosy males. When scientists studied the wing spots, which reflect light in the UV range, invisible to humans, they found they were brighter in the courting females relative to the males of that same season, or relative to females raised in the hotter season.” In a study published today in Science magazine, Prudic and colleagues suggested that the reversal is brought about by the environmental conditions. When transferring sperm, the male butterflies also administer nutrients, increasing the females’ chances of surviving the harsh conditions of a warm, dry season. Therefore, it is in the best interest of the female butterflies to attract males for their supply of nutrients, whereas males will be more selective in choosing females since they are limiting their own chances of survival by mating. As a result, the females that flash their showy spots are more likely to be chosen. Photo Credit: South African...

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