The branch of ecology studying introduced species is a new one that has achieved enhanced recognition of late. Much of the increase in prominence is due to several recent high-profile species introductions (zebra mussel, green crab, Asian longhorned beetle, the West Nile Virus, and purple loosestrife in the continental United States) and the enhanced theoretical rigor of the field.

These introduced species are leading to a dramatic restructuring of ecoystems around the world and to the extinction of thousands of species. Partly as a recognition of the importance and rapid development of this field, Science magazine recently had a special issue reviewing the problem (Vol. 285, No. 5435).

Most of these species were introduced into novel areas due to human activity. Because human mobility and shipping have increased, the number of accidentally introduced species around the world has reached a fever pitch and still escalates. Introduced species are also intentionally introduced as biological control agents and for erosion control, farming, and sport fishing.

Irrespective of the mode of introduction, these species can and have become serious pest species, leading to millions of dollars of economic impact and untold damage to the local ecological balance. Governmental and private funding for basic and applied research on exotic species and permanent research positions focusing exclusively on exotics have each proliferated worldwide. The field of invasion biology will only continue to become more prominent as additional human-facilitated species introductions continue.

Invasion biologists explore the impact of introduced species on the local ecology, the mechanisms behind their introduction, the theoretical bases behind these activities, and the political consequences of exotics. In this lecture and discussion based course for upper level undergraduates and beginning graduate students, we will explore each of these components of invasion biology.