National Geographic researcher Zeray Alemseged unearths a three-million-year-old baby in Ethiopia's Rift Valley. Next, off the southern coast of Florida, dedicated researchers employ Crittercam® to unravel the nurse shark's mating mysteries while there's still time to make a difference. Then off to Panama, where almost 500 years ago the explorer Vasco Nunez de Balboa made the trek through the Darien's steamy jungle, becoming the first European to see the Pacific Ocean. Now an American adventurer attempts to follow Balboa's footsteps. Our last stop, Jasper National Park., high in the Canadian Rockies, spring does not come easily and for newborn youngsters dangers abound.
—Anonymous