Xenotransplantation Ban/Invasive Species Guests: Fritz Bach Professor of Surgery Harvard Medical School Immunologist Beth Israel Deaconess Medical Center Boston, Massachusetts Andy Cohen Marine Biologist San Francisco Estuary Institute Richmond, California Should the use of animal organs in human transplant surgery be banned? This week, a public meeting at the National Institutes of Health considered the question. This hour, we'll talk with a xenotransplantation researcher who wants the practice banned. Plus, a new study shows that large numbers of non-native species have invaded the San Francisco Bay. We'll hear what this means for native species and the habitat.