Fernandina's Flicker (Colaptes fernandinae), a woodpecker found only in Cuba. Pete Oxford/Minden Pictures/Corbis hide caption

itoggle caption Pete Oxford/Minden Pictures/Corbis

A field of unharvested wheat is seen in Ashby-de-la-Zouch, England, in 2012. Wheat wasn't cultivated in Britain until some 6,000 years ago, but DNA evidence suggests early Britons were eating the grain at least 8,000 years ago. Darren Staples/Reuters/Landov hide caption

itoggle caption Darren Staples/Reuters/Landov

Tim Meyers on his four-acre vegetable farm in southwestern Alaska. Behind him: an endless sea of tundra, and a glimpse of the town of Bethel. Eugenie Frerichs for NPR hide caption

itoggle caption Eugenie Frerichs for NPR

An image of Ceres taken by NASA's Dawn spacecraft shows that the brightest spot on the dwarf planet has a dimmer companion. NASA/JPL-Caltech/UCLA/MPS/DLR/IDA hide caption

itoggle caption NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

An overgrowth of Clostridium difficile bacteria can inflame the colon with a life-threatening infection. Dr. David Phillips/Getty Images/Visuals Unlimited hide caption

itoggle caption Dr. David Phillips/Getty Images/Visuals Unlimited

Smoke rises from chimneys of coal-based power plants in the Sonbhadra District of Uttar Pradesh, India. The Washington Post/Getty Images hide caption

itoggle caption The Washington Post/Getty Images

With the technology to conduct more nuanced tests, some companies say they can provide more useful detail about how people think in dynamic situations. Marcus Butt/Getty Images/Ikon Images hide caption

itoggle caption Marcus Butt/Getty Images/Ikon Images

Burmese migrant Thazin Mon Htay and her father Ko Ngwe Htay were trafficked to Thailand to peel shrimp. They worked 16-hour shifts, seven days a week, for less than $10 a day, Ko Ngwe told PBS NewsHour. Jason Motlagh/Pulitzer Center on Crisis Reporting for NPR hide caption

itoggle caption Jason Motlagh/Pulitzer Center on Crisis Reporting for NPR

Crew members pull an oyster dredge in Tangier Sound of the Chesapeake Bay near Deal Island, Md., in 2013. A study found that the Chesapeake Bay shellfishery is a "hot zone" for ocean acidification. Patrick Semansky/AP hide caption

itoggle caption Patrick Semansky/AP

In a landmark new study, researchers found that babies who consumed the equivalent of about 4 heaping teaspoons of peanut butter each week, starting when they were between 4 and 11 months old, were about 80 percent less likely to develop a peanut allergy by age 5. To avoid a choking hazard, doctors say kids should be fed peanuts mixed in other foods, not peanuts or globs of peanut butter. Anna/Flickr hide caption

itoggle caption Anna/Flickr