Anagenesis (also known as phyletic speciation), in which initial founder populations simply diverge through time without a branching event, is an important process of speciation in endemic species of oceanic islands. Takayama et al. investigate the genetic consequences in Acer okamotoanum (Sapindaceae), an anagenetically derived species endemic to Ullung Island, South Korea. No geographical genetic structure within the island and low genetic variation among populations of A. okamotoanum support the concept of initial founder populations diverging through time by accumulation of mutations in a relatively uniform environment without further specific differentiation.
