the bagram base held a fallen comrade ceremony for air force lieutenant roslyn schulte and army reservist shawn pine. service members by the hundreds stopped what they were doing and lined the street to pay their respects as the coffins were driven slowly from the base mortuary to the airstrip. these pictures are rarely seen on television, and were given to us so we could honor america's fallen heroes on this memorial day weekend. >> stahl: the woolly mammoth is the first extinct animal to have its genome decoded, and some scientists believe that one day they may be able to clone one. that may seem like science fiction, but new breakthroughs in d.n.a. research may also help keep today's animals from going extinct. >> i feel like we're in the emergency room of the wildlife business, really. i don't want to see elephants in textbooks or... you know, the way we see dinosaurs. >> stah: so dr. dresser is storing skin samples of lions, gorillas, and hundreds of other species in something she calls a frozen zoo. so if any one of these animals were go to extinct, you could bring them back. >> in