One is definitely tourism.
Explanation:
The factor that jeopardizes the ecosystem in Eastern Europe is the tourism industry. Individuals simply travel there and have a fabulous time yet they don't pay attention and leave beaches dirty. They are not dealing with nature and the administrations can't do much since sightseers leave a lot of money for the nations.
This movement is called convection. It can be found in liquids, gasses and rheids - solids that can also experience movement ( on a big time scale), such as the earth mantle. One of the types of convection is diffusion: net movement of gasses from higher to lower concentration areas.
Because of genetic variation