Why vultures have shitty breathThe Egyptian vulture, in addition to feeding on carrion like any other respectable vulture, has an appetite for dung. Not content with the culinary rewards of rotten meat, Neophron percnopterus will actively seek out and consume cow and sheep feces and Spanish researchers think they know why. Egyptian vultures, unlike other vultures, sport bright yellow faces. The colour yellow in biological systems is derived from pigments called carotenoids, which vertebrates cannot synthesize but must obtain from their diets. While rotten meat contains little yellow pigment, animal waste is full of the stuff. What could be the evolutionary advantage of a dung-based diet? One idea is that a vulture’s bright yellow face may indicate to potential mates or rivals its excellent state of health. After all, any animal that can subsist on a food source rife with parasites and bacteria must be pretty fit.Source: Nature–Zoe CormierOzone hole weirdnessSatellite data show that the annual hole in the ozone layer over Antarctica is different this year. The hole is one-third smaller than in recent years, and has taken on a double-lobed shape that has not been seen since satellite observations began in the 1970s.Each year in September and October, a gap in the radiation-blocking ozone layer forms over the South Pole, caused by CFCs and other atmospheric pollutants. Ozone-depleting chemicals were banned by international treaty in 1987, but the chemicals are long lasting and the recent shrinkage is too rapid to have been caused by the ban. NASA scientists cite unusual weather patterns to explain the strange size and hourglass shape of this year’s hole.Source: New York Times–Matt Asma‘Tenth planet’ (not) discoveredAn object half the size of Pluto has been found orbiting the Sun. Two CalTech astronomers, Chad Trujillo and Mike Brown, discovered the object. They named it Quaoar, after a creation figure in the story tradition of the Tongva aboriginals, whose homeland is in California. Although Quaoar is the largest object discovered in our solar system since the discovery of Pluto in 1930, its discoverers don’t consider it a planet. Like Pluto, it appears to be just a particularly large member of the Kuiper comet belt at the edge of the solar system. Like many astronomers, Trujillo and Brown don’t believe Pluto would be designated a planet either if it were discovered today. In fact, they expect that other similar-sized Kuiper Belt objects will be discovered in the next few years, including some larger than Pluto.Source: globeandmail.com–David ShigaFearful frogs flee from fire Researchers at the University of Würzburg announced last week results that will surely shake the world of behavioural science: frogs flee from the sound of fire. Through years of exhaustive research, three German biologists proved conclusively that the West African reed frog will hop in the opposite direction of the sounds of a brush fire as reproduced by a handheld stereo. This study answers a question that has plagued biologists since time immemorial, but it also indicates just how far we have to go in understanding amphibious fire evasion. Do other species of frog flee from fire as well? Does fleeing from swaths of flaming grass increase one’s chances of sexual success? Could there even be a “fire-fearing gene?” Clearly, more funding and research hours are needed to probe more deeply into the behavioural and adaptive significance of fire avoidance. Source: Natural History–ZoË CormierDolly’s father to clone human embryosIan Wilmut, a scientist at the Roslin Institute in Scotland where Dolly the Sheep was cloned, plans to ask for permission to clone human embryos. The application will have to pass many ethics and review committees, but he expects approval within six months.Wilmut wants to use the same nuclear transfer technique that created Dolly. All animals cloned in this way have proved to be defective, including Dolly, who has premature arthritis. However, Wilmut wants to clone human embryos to obtain stem cells, not to make babies. The stem cells would be used in research to grow new tissues and organs. Reproductive human cloning is illegal in many countries, including Great Britain.Source: BBC Online–Matt Asma
