Disjunct distribution

The disjunction is in the ecology of a complex part ( exclave ), which was spatially separated from the rest of the range of a plant or animal species and can not be bridged with the usual spread these other types, but still represents a habitat.

Disjunction, for example, a result of existing and complex losses. So may have been separated by ice advances during the ice ages areas. Conversely remained after a new climate change often widely separated relict populations left, for example, in the mountains or colder zones.

For the (sub - ) population in such a disjunction, this separation can be the beginning of a new speciation ( speciation ). Loses the disjunction habitat function ( ie is uninhabitable ), the population can not migrate and die from inevitable. The speciation is thus effected either by spezialisierende adaptation to the local habitat at constant conditions or by necessary adaptation to changes in disjunction.

With the stepping stone concept you're trying to counter a disjunction.