Researchers claimed in late 2010 that they found bacteria in Mono Lake, Calif., that survived on the poison arsenic in the place of an element thought essential to life. The report was immediately greeted with skepticism from the scientific community. Ben Margot/AP hide caption

itoggle caption Ben Margot/AP

A group of harbor porpoises in San Francisco Bay, photographed from the Golden Gate Bridge. Harbor porpoises haven't been seen in the bay since the 1930s. Researchers believe World War II activity may have contributed to their disappearance. The Navy strung a seven-mile underwater net across the mouth of the bay to keep out enemy submarines. William Keener/Golden Gate Cetacean Research hide caption

itoggle caption William Keener/Golden Gate Cetacean Research

A Kemp's ridley sea turtle like this one traveled 4,600 miles across the Atlantic ocean in 2008. After being rehabilitated in Portugal, it is being reintroduced into its native Gulf of Mexico waters on Tuesday. US EPA via flickr hide caption

itoggle caption US EPA via flickr

Leonardo DaVinci noted that when trees branch, smaller branches have a precise, mathematical relationship to the branch they sprang from. iStockphoto.com hide caption

itoggle caption iStockphoto.com