Invasion
a term that should be used with caution, although most cell biologists would follow Abercrombie in meaning the movement of one cell type into a territory normally occupied by a different cell type, some pathologists might not agree.
invasion can refer to the radiation of a clade or lineage into an environment or habitat not previously occupied; invasion can also refer to the establishment of a species or lineage to a new location or environment by natural or anthropogenic means.
Dictionary > Invasion
