INVASIVE SPECIES AND IT'S IMPACT ON ENVIRONMENT

        invasive species , also called  introduced species ,  alien species , or  exotic species , any nonnative  species  that significantly modifies or disrupts the  ecosystems  it colonizes. Such species may arrive in new areas through natural  migration , but they are often introduced by the activities of other species. Human activities, such as those involved in global commerce and the  pet  trade, are considered to be the most common ways invasive  plants ,  animals , microbes, and other organisms are transported to new  habitats . Most introduced species do not survive extended periods in new habitats, because they do not possess the evolutionary adaptations to adjust to the challenges posed by their new surroundings. Some introduced species may become invasive when they possess a built-in competitive advantage over indigenous species in invaded areas. Under these circumstances, new arrivals can establish breeding populations and thrive, especially if the ecosystem lacks natural