Figure 1. The role of spatial and temporal scale in defining ecological and evolutionary processes. (1) Range and lifetime of an individual; (2) population scale operating in ecological time (e.g. competition); (3) population scale operating over evolutionary time (e.g. differentiation); (4) species scale (e.g. adaptive radiation). (Redrawn from Haila, 1990).

Figure 2. Conceptual model depicting the relationship between geographical variables and evolutionary process (from Whittaker, 1998). The model indicates a trend from micro- to macro-evolutionary changes as island isolation and area increase: large, distant islands are most disharmonic and possess most vacant niche space, perfect platforms for spectacular radiations; tiny islands, even if isolated, fail to provide for the persistence of large populations and complex ecosystems, and thus feature impoverished biotas of widespread species; large near-mainland islands typically contain a full balance of species and lack the long-term isolation that favours lineage radiation. For terms, see text, apart from ‘anagenesis’, which refers to speciation with little or no radiation, most prevalent on single, isolated islands in contrast to the radiations more prevalent on archipelagos.

Figure 3. The equilibrium theory of island biogeography (ETIB) proposed by MacArthur and Wilson (1967) showing the relationship of distance from an island and source area on immigration (I), island area on extinction (E), and the intersection of both at an equilibrial point to produce a turnover rate (T) at a predictable species number (S). The roughly triangular area bounded by the darkened lines to the left of the turnover intersection point delimits the turnover rates and species numbers theoretically possible before equilibrium is reached (fl, far large; ns, near small).