Teeth from a cremated child were excavated from a site believed to be 11,500 years old. The color differences show uneven burning. The scale is in millimeters. Science/AAAS hide caption

itoggle caption Science/AAAS

Scientists hope to use a fungus to keep malaria-carrying mosquitoes like the Anopheles gambiae species from growing resistant to insecticides. Courtesy of James Gathany/CDC hide caption

itoggle caption Courtesy of James Gathany/CDC

A new study finds that radio waves from a cell phone can affect the metabolism of brain cells, though there is no evidence that the effect is harmful. Here, a pedestrian talks on her phone on a street in San Francisco. Justin Sullivan/Getty Images hide caption

itoggle caption Justin Sullivan/Getty Images

Some 16,000 years ago, people may have been curling up next to the fire with red foxes. iStockphoto.com hide caption

itoggle caption iStockphoto.com

An American black bear from the Kenai Peninsula in Alaska. A new study found that a bear's metabolism in hibernation drops by nearly 75 percent while its body temperature falls just slightly. Oivind Toien/Institute of Arctic Biology, University of Alaska, Fairbanks hide caption

itoggle caption Oivind Toien/Institute of Arctic Biology, University of Alaska, Fairbanks