Perch exposed to the anxiety drug oxazepam were more daring and ate more quickly than fish that lived in drug-free water. Courtesy of Bent Christensen hide caption

itoggle caption Courtesy of Bent Christensen

An official with the Korea Meteorological Administration shows a seismic image of a tremor caused by North Korea's nuclear test, in Seoul on Tuesday. Kim Jae-Hwan/AFP/Getty Images hide caption

itoggle caption Kim Jae-Hwan/AFP/Getty Images

Vegetation like the kind growing here at Michigan State University's Kellogg Biological Station could one day be used to feed small biofuel refineries spread throughout the Midwest. J.E.Doll/Michigan State University hide caption

itoggle caption J.E.Doll/Michigan State University

Scientists at the Large Hadron Collider announced the discovery of the Higgs boson on July 4, the long-sought building block of the universe. This image shows a computer-simulation of data from the collider. Barcroft Media/Landov hide caption

itoggle caption Barcroft Media/Landov

A section of the Sutter's Mill meteorite, dubbed "Darth Vader," is studied at a lab at the University of California, Davis. The meteorite is made of carbonaceous chondrite, which contains materials that formed the planets of the solar system. UC Davis hide caption

itoggle caption UC Davis

The fossil remains of Dickinsonia, an Ediacaran organism that's long been extinct. Scientists have long assumed these early life forms lived in the sea, but a new study argues they emerged on land. G. Retallack/Nature hide caption

itoggle caption G. Retallack/Nature

Delegates attend the last day of the U.N. climate talks in Doha, Qatar, on Friday. U.N. climate negotiators locked horns on the final day of talks in Doha to halt the march of global warming, deeply divided on extending the greenhouse gas-curbing Kyoto Protocol and funding for poor countries. Karim Jaafar/AFP/Getty Images hide caption

itoggle caption Karim Jaafar/AFP/Getty Images

An iceberg that likely calved from Jakobshavn Isbrae, the fastest glacier in western Greenland. Ian Joughin/Science/AAAS hide caption

itoggle caption Ian Joughin/Science/AAAS

While lots of labels tout their lack of genetically modified ingredients, if California's Prop. 37 succeeds, foods containing GMOs would have to be labeled. Paul Sakuma/AP hide caption

itoggle caption Paul Sakuma/AP