The notion of the “metapopulation” (or “population of populations”) has been kicking around for a while. Richard Levins first introduced the term in the late 1960s, but an inkling of the biological importance of the spatial sub-structuring of species has been around much longer. In the 1960s, the island biogeography theory of MacArthur and Wilson considered the dynamic interplay of extinction and colonization in determining distributions of organisms within a fragmented (island) landscape. The idea has even earlier roots in the population genetics literature, where the idea can be traced back to the 1930s and Sewell Wright's shifting balance theory.