▪ Abstract Islands have traditionally been considered to be any relatively small body of land
completely surrounded by water. However, their primary biological characteristic, an
extended period of isolation from a source of colonists, is common also to many situations
on continents. Accordingly, theories and predictions developed for true islands have been
applied to a huge array of systems, from rock pools, to single tree species in forests, to
oceanic islands. Here, we examine the literature on islands in the broadest sense (ie …