Findings

Science  24 Jun 2011:
Vol. 332, Issue 6037, pp. 1489
  1. The Iceman's Last Meal

    Ever since he was discovered in the Italian Alps in 1991, Ötzi the 5200-year-old Iceman has been dishing out information about Neolithic life. Scientists at the 7th World Congress on Mummy Studies 12 to 16 June reported new findings on the Iceman's dietary and dental habits, and even his eye color.

    CREDIT: WERNER NOSKO/REUTERS/LANDOV

    Researchers led by microbiologist Frank Maixner of the Institute for Mummies and the Iceman in Bolzano, Italy, reported at the meeting that they had sequenced the DNA of animal fibers in the Iceman's stomach to reveal his last meal: the meat of an Alpine ibex. New three-dimensional images of the Iceman's teeth by dentist Roger Seiler and anatomist Frank Rühli of the Center for Evolutionary Medicine at the University of Zürich, meanwhile, show that the Iceman was plagued by both periodontal disease and cavities.

    And a team led by geneticist Angela Graefen of the Institute for Mummies and the Iceman reported sequencing the Iceman's whole genome, despite the highly fragmented nuclear DNA. The genome has already revealed some surprises. One preliminary finding shows that the Iceman probably had brown eyes rather than the blue eyes found in many facial reconstructions done by artists. http://scim.ag/_iceman

  2. Dinosaurs May Have Been Warm and Cuddly

    Dinosaurs' reputation as cold-hearted beasts may be undeserved. By analyzing teeth from fossils of the huge four-legged dinosaurs Brachiosaurus and Camarasaurus, researchers have found hints that strengthen the idea that some dinosaurs may have been warm-blooded, or at least better at conserving body heat than modern reptiles are.

    The researchers measured isotopes of chemical elements in tooth enamel from 11 fossils dug up in Oklahoma, Wyoming, and Tanzania. The lower the temperature at which the enamel forms, the more the isotopes carbon-13 and oxygen-18 tend to bond or clump together. The bond structure in the dino teeth suggested the enamel formed between 36° and 38°C, similar to mammalian body temperature. It's not the final word on warm-blooded dinosaurs, the authors say in a paper published online this week in Science. If these “gigantotherms” were this warm, they would have had to release heat through some unknown mechanism to avoid overheating, possibly through their long necks and tails.

  3. Neutrino Discoveries to Come?

    Sometimes it's not the results themselves but the prospects they raise that jazz scientists. Physicists in Japan have directly observed particles called muon neutrinos transforming into others called electron neutrinos. Obtained by shooting trillions of muon neutrinos from an accelerator lab in Tokai to the subterranean Super-Kamiokande particle detector 295 kilometers away, the observation from the T2K experiment was expected. Nevertheless, it excites physicists because the effect appears to be so large that future experiments may have a relatively easy time spotting other phenomena. “If this result holds up, … we've got kind of a fun decade ahead of us in neutrino physics,” says Mark Messier, a neutrino physicist at Indiana University, Bloomington.

    In particular, physicists are keen to compare the rate at which a muon neutrino becomes an electron neutrino to that at which a muon antineutrino becomes an electron antineutrino. Any difference would violate a symmetry between matter and antimatter known as charge-parity symmetry, and might help explain why the universe evolved to contain so much of the former and so little of the latter. However, Messier says, such an experiment is at least a decade away. http://scim.ag/_neutrino

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