National Geographic Emerging Explorer Tierney Thys is a marine biologist and documentary filmmaker whose work explores the breadth of animal diversity from pole to pole and chronicles global environmental change. Tierney is a world authority on the giant ocean sunfish, Mola mola, and has led numerous expeditions worldwide from Africa to Baja, Japan, Indonesia, and the Galápagos Islands to study these bizarre jelly-eating behemoths. Tierney has also developed and guided National Geographic student marine biology expeditions in Monterey Bay.