'3-Weed Note' Artwork by Patterson Clark - alienweeds.com Courtesy of Patterson Clark hide caption

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A solitary bison in Yellowstone National Park. Amelia Templeton/NPR hide caption

itoggle caption Amelia Templeton/NPR

Institute for Marine Mammal Studies veterinary technician Wendy Hatchett takes a skin sample from a dead bottlenose dolphin that was found on Ono Island, Ala., and brought for examination to Gulfport, Miss., on Tuesday. Patrick Semansky/AP hide caption

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Oil spill claims czar Kenneth Feinberg speaks about the claims process Feb. 18 at the Mississippi College Law Review Symposium in Jackson, Miss. Feinberg faces criticism from Gulf Coast residents about the slow pace and low amount of payments. Rogelio V. Solis/AP hide caption

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Researchers aboard the Atlantis, a research vessel operated by the Woods Hole Oceanographic Institution, examine core samples brought up from the sea floor of the Gulf of Mexico by the deep-sea submersible Alvin on Nov. 24, 2010. The scientific community is conflicted about the lack of direction, coordination and funding in studying the aftermath of the Gulf of Mexico oil spill. Richard Harris/NPR hide caption

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A giant clam and healthy coral reef on the east side of Palau. The coral reefs of Palau are part of a massive interconnected system that ties together Micronesia and the Western Pacific. Ian Shive/World Resources Institute hide caption

itoggle caption Ian Shive/World Resources Institute

A house in Phoenix outfitted with the solar panels that SolarCity leases to its customers. Courtesy of SolarCity hide caption

itoggle caption Courtesy of SolarCity

A mature Atlantic tomcod collected from the Hudson River. These tomcod evolved to handle excessive amounts of industrial pollutants, like PCBs and dioxin, in the water. Science/AAAS hide caption

itoggle caption Science/AAAS