Match each vocabulary word with its definition. 1 . referring to plants or animals introduced to an area, which plants or animals threaten indigenous species cyclical migration 2 . the forced removal of a group of individuals of common ancestry from an area diaspora 3 . people who leave their homeland seeking safety in a foreign country ethnic cleansing 4 . the scattering of a group of people outside of their homeland invasive 5 . the movement of people between places on a regular basis out-migration 6 . movement from one's homeland to another country refugees