History of animal testing of visual areas in cats and monkeys, and provided physiological evidence for the critical period for the development of disparity sensitivity in vision (i.e.: the main cue for depth perception), and were awarded a Nobel Prize for their work. In 1996 Dolly the sheep was born, the first mammal to be cloned from an adult cell. The process by which Dolly the sheep was cloned utilized a process known as nuclear transfer applied by lead scientist Ian Wilmut. Although other scientists were not immediately able to replicate the experiment, Wilmut argued that the experiment was indeed repeatable, given a timeframe
Marine mammal park California was the first park to display an orca in captivity, although the orca died after two days. The Vancouver Aquarium was responsible for the first orca ever held alive in captivity, Moby Doll, for 3 months in 1964. Between the 1970s and the 1990s, technical advances and the public's increasing interest in aquatic environments prompted a shift to large marine mammal parks with cetaceans (mostly orcas and other species of dolphin) as attractions. Within this time SeaWorld USA evolved as the most prominent chain of marine mammal parks, with operations in Orlando, Florida, San Diego, California, San Antonio, Texas,