Hen­der­son Island, which lies in the east­ern South Pacif­ic, is one of the few atolls in the world whose ecol­o­gy has been prac­ti­cal­ly untouched by a human pres­ence. Its iso­lat­ed loca­tion pro­vides the ide­al con­text for study­ing the dynam­ics of insu­lar evo­lu­tion and nat­ur­al selec­tion. It is par­tic­u­lar­ly notable for the 10 plants and four land birds that are endem­ic to the island.