Random Samples

Science  23 Feb 2007:
Vol. 315, Issue 5815, pp. 1059

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  1. NETWATCH: On The Hoof

    What does a dromedary camel loping across a sand dune have in common with a Lippizaner stallion high-stepping around a ring and a rhinoceros luxuriating in a mud puddle? They are all ungulates, mammals that typically sport the overgrown toenails known as hooves. To learn more about the group or individual species, drop by the Ultimate Ungulate page from Brent Huffman, a keeper at the Toronto Zoo in Canada.

    Introductory pages summarize some of the surprises from recent molecular studies on mammalian evolution, which distanced the ungulates from elephants and aardvarks, long thought to be their next of kin. Hoofed animals are actually more closely related to bats. Species accounts cover most of the more than 250 ungulates, offering details on the animals' diet, habitat, behavior, and range.



    Fifteen bird species have been newly discovered by a DNA identification technique called bar coding, researchers reported online 19 February in Molecular Ecology Notes. They've also uncovered six new bat species in bat-rich Guyana.


    The Barcode of Life project seeks to determine the DNA sequence of the same mitochondrial gene in millions of Earth's fauna. The variations in the sequence provide a unique, easy-to-read species identifier, scientists say.

    Until now, bar coding hadn't been tested in either mammals or widespread bird populations. For the bird probe, evolutionary biologist Paul Hebert of the University of Guelph in Canada and colleagues cataloged DNA from 2500 specimens supplied by museums and bird banders in the United States and Canada. The samples represent 643 of the 690 known North America-based species. Bar codes supplied some surprises, revealing 15 “cryptic” species: birds so similar to other birds that they had not been seen as distinct. What's more, eight supposed gull species turned out to be just one, and birds from 14 other supposed species were virtually identical to at least one other species.

    In the mammalian end of the project, Hebert's team turned to Guyana, taking tissue samples from 840 bat specimens in the Royal Ontario Museum. There was concern that the species would be too closely related to reveal genetic differences. Yet the researchers easily distinguished the 80 or so species in the collection and discerned several new ones, Hebert says. Such studies have the potential to “break bar coding” by proving to skeptics that species can't always be distinguished on the basis of just one gene, says project member Mark Stoeckle of Rockefeller University in New York City. “But it's worked everywhere it's been applied.”


    As genomic information piles up at an exponential rate, sorting through it all has become overwhelming. In the hopes that with enough eyes, breakthroughs will materialize, the Swiss drug company Novartis has helped create a free and open database on the genetics of type 2 diabetes.

    Posted at www.broad.mit.edu/diabetes, the Diabetes Genetics Initiative is a collaboration between Novartis, the Broad Institute of the Massachusetts Institute of Technology and Harvard University, and Lund University in Sweden. Launched in 2004 and completed last week, it contains information on the genomes of 1500 people with diabetes and 1500 without in Sweden and Finland.

    Alan Shuldiner, an endocrinologist and geneticist at the University of Maryland School of Medicine in Baltimore, suspects that the Novartis collaboration is “proactively providing their data in anticipation that others will do the same.” A dozen teams are working along the same lines with different populations, from the Pima Indians in Arizona to Massachusetts residents in the Framingham Heart Study.



    Lloyd Levine doesn't intend the “How Many Legislators Does It Take to Change a Light Bulb Act” of 2007 as a joke. The California assemblyman, a Democrat, is preparing a bill that would effectively ban the sale of household incandescent bulbs in the state by 2012. Compact fluorescents, called twisties by some, are cheaper and more energy-efficient, he says.

    The Levine ban “is probably the most aggressive proposal we've heard to date,” says R. Neal Elliot of the nonprofit American Council for an Energy-Efficient Economy. Elliot says compact fluorescents are a green “no-brainer” because they use less electricity—and thus reduce carbon emissions—and with life spans of up to 8 years, they last more than long enough to recoup their high initial cost. John Geesman of the California Energy Commission says he thinks the proposal might fly if it exempts certain fixtures, such as the lights inside microwave ovens, for which there aren't effective substitutes.