All Things Considered

When Duan Biggs was growing up in the Kruger National Park in South Africa, he used to watch elephants and rhinos walking past his bedroom window. He left home to pursue degrees in biology and economics, and when he returned in 2011 the park looked and sounded "like a pseudo war zone," he says.

"There'd be helicopters flying overhead all the time," he says. "I remember one afternoon coming back to my home from a game drive and the bush was crawling with people with assault rifles, from the army, from the police, and from National Parks. They were looking for poachers."

Scientists say they have, for the first time, cloned human embryos capable of producing embryonic stem cells.

The accomplishment is a long-sought step toward harnessing the potential power of embryonic stem cells to treat many human diseases. But the work also raises a host of ethical concerns.

A serial killer who committed suicide in an Alaska jail last year confessed to murdering at least 11 people across the country. But Israel Keyes didn't name names, and investigators trying to figure out who he killed are running into a major stumbling block: There is no unified, mandatory national database for missing persons.

Nearly 700 presidential hopefuls have thrown their names into the ring for Iran's June 14 presidential elections. But two last-minute entrants have altered the shape of the already-chaotic race: a former president once dismissed as a has-been and Iran's chief nuclear negotiator.