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Past Shows
February 28, 2009
 Download an MP3 of the entire program (22MB).
Secrets in Scavenger Scat
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a brown hyena, courtesy of South African Tourism
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Dr Lucinda Backwell was a little surprised when a colleague asked her to help identify some strange threadlike forms in a piece of 200,000 year-old fossilized hyena dung. She was even more surprised to discover that it was human hair. The oldest fossil hair found before this was less than 10,000 years old. This hair could be from early Homo sapiens, but might also be from one of the several other species of early humans we shared the world with at that time. Dr. Backwell is a paleo-anthropologist at the University of Witwatersrand in Johannesburg, South Africa.
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Leaping Lizards
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a green anole, Copyright Lycaon, from Wikimedia Commons
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Green anole lizards are notable both because they're good leapers, and also because they are among the lizards who can abandon their tails - dropping them off when a predator grabs them, and growing them back later. Dr. Gary Gillis, a biologist at Mount Holyoke College in Massachusetts, was interested in what effect the second ability had on the first. A distressing one, for the lizard, as it turns out. Without their tails, they tend to lose control and tumble backwards during their leaps, though they seem eventually to learn how to compensate.
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The Evolution of Moral Disgust
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A look of Disgust, Copyright Science/AAAS
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Have you ever wondered why we use the term "disgusting" to describe someone's behaviour when they commit a moral transgression? Is it simply a handy metaphor or is there more to it than that? Hanah Chapman, a PhD candidate at the University of Toronto's Affect and Cognition Lab, has been looking into this. Ms. Chapman tested people's reactions to a variety of unpleasant situations -- drinking a gross liquid, looking at nasty pictures and being treated unfairly -- and she found that in all cases, people tended to react with a characteristic look of disgust. Ms. Chapman suggests that our tendency to react to unpleasant behaviour with a look of disgust evolved from our aversive reaction to toxic or putrid food.
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Alien life on Earth
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Alien life on Earth may resemble common microbes. Copyright United States Department of Agriculture
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It wasn't long ago that the idea of finding extraterrestrial life belonged clearly in the realm of science fiction. But the tides have turned and, now, many researchers feel that we'll find evidence of life on another world within the next decade or so. The ramifications, of course, are huge: in all likelihood, it would mean that life is scattered widely around the universe. But there's another intriguing option you don't hear so much about -- that alien life may already exist right here on Earth. Dr. Paul Davies, a cosmologist and founder of the Beyond Centre for Fundamental Concepts at Arizona State University, thinks it's possible that life may have arisen more than once here on Earth, and he suggests we launch a "Mission to Earth" to look for the alien life living in our own backyard. It most likely would take the form of a type of microbe that is biochemically different from the forms of microbial life we know about already; and could be living in extreme environments, such as undersea hydrothermal vents.
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Kepler Mission
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The Kepler spacecraft - courtesy NASA
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If we want to find life on other planets in the universe, we first have to find Earth-like planets where life could exist. Of the 300 or so extra-solar planets we have discovered so far, none has been Earth-like. Most have been hot, roiling gas giants where no life could live. So now NASA is launching the Kepler satellite - the first mission designed specifically to look for Earth-like planets. The space-based observatory will stare at 100,000 nearby stars, for 3 years without blinking - hoping to detect the subtle movement of small, Earth-like planets as they orbit around their stars. One of the scientists in charge is Dr. David Koch, the Deputy Principal Investigator on the Kepler mission, at NASA's Ames Research Centre in California. Kepler is scheduled to launch on March 6.
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Theme music bed copyright Raphaël Gluckstein.
Creative Commons License by-nc-nd-2.0
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