Table 1.

Types of Dispersal Events in Earth Ecology and Cancer Ecology

Types of dispersal events	Earth ecology	Cancer ecology
Jump dispersal
Long distance dispersal accomplished during a relatively short period of time (occurs infrequently but explains species in different sites)	Movement of species with wind, or carried by artificial means (movement of sparrows from England to North America)	Movement of cancer cells through the bloodstream.
Diffusion
Slow dispersal of individuals spreading out from the margins of the species' range (accomplished over generations	Movement of species as they reproduce and move to nearby favorable environments (sparrows in North America)	Growth of a primary tumor or a cancer at a metastatic site.