Island gigantism

Inselgigantismus is a biological phenomenon in which body size of species or the size of individuals, seeds or flowers of plants species that live on an island for generations increases significantly away. This can be observed in island populations of a subspecies, but also in islands endemic subspecies and species. Trigger of Inselgigantismus is often the absence of predators, which cancels the evolutionary advantage of a small, concealable body better. A counter-rotating phenomenon is the so-called Inselverzwergung.

As for the size change in mammals a so-called island rule describes smaller after the large species, small species but larger. As a rule of thumb, a pursuit to a mass of 1 kg is postulated on islands, which purports to be the biologically effective measure of the average mammalian blueprint on average, for individual families but deviates.

Examples of Inselgigantismus in plants are also quite common; a well-known example is the extremely large fruits of the coco de mer.