With the help of researcher Sabudo Boraru (right), anthropologist Chris Campisano, of Arizona State University, takes samples from the fossil-filled Ledi-Geraru project area in Ethiopia. The jawbone was found nearby. Courtesy of J Ramón Arrowsmith hide caption

itoggle caption Courtesy of J Ramón Arrowsmith

Along with sperm, the in vitro procedure adds fresh mitochondria extracted from less mature cells in the same woman's ovaries. The hope is to revitalize older eggs with these extra "batteries." But the FDA still wants proof that the technique works and is safe. Chris Nickels for NPR hide caption

itoggle caption Chris Nickels for NPR

About 1 in 3 patients with dementia who live in nursing homes are being sedated with antipsychotic drugs, the GAO says. Outside nursing homes, about 1 in 7 dementia patients are getting the risky drugs. Wladimir Bulgar/iStockphoto hide caption

itoggle caption Wladimir Bulgar/iStockphoto

Students Patrick Rohrer, Sarah Warthen, Alix Piven and Lauren Urane are led by Mercyhurst University Archeologist Andy Hemmings. Their project has picked up where Florida's State Geologist Elias Sellards left off in 1915. Sellards led an excavation of the site where workers digging a drainage canal found fossilized human remains. Greg Allen/NPR hide caption

itoggle caption Greg Allen/NPR

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

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

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

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

It's a good start when experimental compounds stop the proliferation of cancer cells in the lab. But, as many researchers have learned the hard way, that's just an early step toward creating a worthwhile treatment. Science Source hide caption

itoggle caption Science Source

The size of the brain of a chimpanzee (right) is considerably smaller than that of a human brain. Probably multiple stretches of DNA help determine that, geneticists say. Science Photo Library/Corbis hide caption

itoggle caption Science Photo Library/Corbis