Comparison of even-toed ungulate and cetaceans genetic material has shown that the closest living relatives of whales and hippopotamuses is the paraphyletic group Artiodactyla. Dan Graur and Desmond Higgins were among the first to come to this conclusion, and included a paper published in 1994.
Definition of roundâtrip. : a trip to a place and back usually over the same route.
Travel is the movement of people between relatively distant geographical locations, and can involve travel by foot, bicycle, automobile, train, boat, bus, airplane, or other means, with or without luggage, and can be one way or round trip. Travel can also include relatively short stays between successive movements.