Random Samples

Science  26 Feb 2010:
Vol. 327, Issue 5969, pp. 1065

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  1. Africa's Iron-Age Healers?


    Last month, archaeologists working at a site in northern Ghana uncovered the most detailed evidence yet of a highly sophisticated and previously unknown Iron Age society. A team led by Benjamin Kankpeyeng of the University of Ghana in Legon excavated part of an earthen mound containing 92 whole and broken terra-cotta figurines of humans and mythical creatures. Radiocarbon dates from similar mounds in the region place the time between 600 C.E. and 1200 C.E.

    The mound, which miraculously escaped decades of heavy looting in the region, may have served as an ancient shrine. Team co-director Timothy Insoll of the University of Manchester in the United Kingdom says the figurines have what appear to be libation holes to hold ritual drinks for a deity. There's also a ritually arranged human skull: “The jaw was removed, the skull was turned face-down, and the teeth were snapped out and placed nearby,” Insoll says.

    The finds open a major window on ritual life in West Africa before the Islamic era, says Christopher DeCorse, an archaeologist at Syracuse University in New York state: “It's analogous to the discovery of Upper Paleolithic rock art in Europe.”

    The deposits, which included grindstones for pulverizing plants, could be related to “traditional healing practices,” Kankpeyeng notes. The team hopes to find further clues from the nearby remains of ancient riverbank settlements. The group has been excavating the site of Yikpabongo, first discovered in 1985, since 2007.

  2. Heated Politics

    The fallout from “Climategate” is raining down into state politics. On 9 February, the Utah House of Representatives passed a resolution stating that there is no evidence that the world is warming and urging the U.S. Environmental Protection Agency (EPA) to revoke its “endangerment” ruling that carbon dioxide is a threat to public health.

    Apparently referring to the controversial leaked e-mails from a climate center in the United Kingdom (Science, 4 December 2009, p. 1329), the Utah resolution contends that “communications between climate researchers around the globe … indicate a well organized and ongoing effort to manipulate global temperature data.”

    Citing the same concerns, the state of Texas on 16 February sued EPA to overturn the endangerment finding. The same day, Virginia's attorney general filed court petitions questioning EPA's ruling.

    The Utah resolution, backed by all of the Republican representatives, passed 56 to 17. The bill now goes to the state Senate, which is 72% Republican.

  3. Dimly Lit Teens

    Video games and texting are not the only reasons teenagers don't go to bed when they should. Lack of exposure to outdoor light is messing with their bodily rhythms and keeping them from getting sleepy when they should, according to research from the Rensselaer Polytechnic Institute (RPI) in Troy, New York.

    A team led by Mariana Figueiro of RPI's Lighting Research Center conducted an experiment at a well-lit school in Chapel Hill, North Carolina, which has skylights that allow students maximal exposure to daylight. For 5 days, 11 eighth-graders wore orange glasses that blocked shortwavelength blue light, the kind that lab experiments have shown is important for setting the circadian clock. Researchers found that at the end of the week, the onset of sleep-inducing melatonin in the children was delayed by a half-hour.

    “The amount of light we get indoors is below threshold for activation of the circadian system,” says Figueiro, whose report appeared last week in Neuroendocrinology Letters. This contributes to the fact that “some kids can't fall asleep before 2 or 3 a.m.”


    Brown University sleep expert Mary Carskadon says the experiment lacked controls. But she agrees with Figueiro that the shortage of outdoor light in most schools—compounded by the indoor-oriented existence of the modern teen—may be contributing substantially to below-par school performance.

  4. Saint Loses Her Head


    For more than 600 years, citizens of the parish of Vadstena in Sweden have venerated two skulls said to have been those of St. Birgitta (1303–1373) and her daughter Katarina.

    In the 1950s, anthropologists scrutinized the skulls and concluded that they were from women aged 60 to 70 years and 50 to 55 years, which could have fit the mother-daughter scenario. But modern science has shattered the myth.

    Marie Allen, a forensic geneticist from Uppsala University in Sweden, used the relics to test her new method for analyzing mitochondrial DNA (mtDNA) from degraded samples. MtDNA from the two skulls, which is inherited only from the mother, showed both were female but “they were certainly not mother and daughter,” Allen says. What's more, carbon-14 dating revealed that St. Birgitta's putative skull is at least a century too old to be the real thing. The other skull is a couple of centuries too late.

    Allen, who published her results in PLoS ONE on 16 February, says the parish is not too disappointed with the findings: “They are very open-minded, and they wanted to know the truth about their relics.”