allopatric speciation The formation of new species from the ancestral species as a result of the geographical separation or fragmentation of the breeding population. Separation may be due to climatic change, causing the gradual fragmentation of the population in a few surviving favourable areas (e.g. during glaciation or developing aridity), or may arise from the chance migration of individuals across a major dispersal barrier. Genetic divergence in the newly isolated daughter populations ultimately leads to new species; divergence may be gradual or, according to punctuationist models (see PUNCTUATED EQUILIBRIUM), very rapid. The populations must evolve some sort of sexual or genetic isolating mechanism that prevents them from interbreeding should they come into contact again later.

allopatric speciation The formation of new species from ancestral species as a result of the geographical separation or fragmentation of the breeding population. Separation may be due to climatic change, causing the gradual fragmentation of the population in a few surviving favourable areas (e.g. during glaciation or developing aridity), or it may arise from the chance migration of individuals across a major dispersal barrier. Genetic divergence in the newly isolated daughter populations ultimately leads to new species; divergence may be gradual or, according to punctuationist models (see punctuated equilibrium), very rapid. The populations must evolve some sort of sexual or genetic isolating mechanism that prevents them from interbreeding should they come into contact again later. Compare sympatric speciation.

allopatric speciation The formation of new species from the ancestral species as a result of the geographical separation or fragmentation of the breeding population. Separation may be due to climatic change, causing the gradual fragmentation of the population in a few surviving favourable areas (e.g. during glaciation or developing aridity), or may arise from the chance migration of individuals across a major dispersal barrier. Genetic divergence in the newly isolated daughter populations ultimately leads to new species; divergence may be gradual or, according to punctuationist models (see PUNCTUATED EQUILIBRIUM) very rapid.

allopatric speciation Formation of new species from the ancestral species as a result of the geographic separation or fragmentation of the breeding population. Genetic divergence in the newly isolated daughter populations ultimately leads to new species; divergence may be gradual or, according to punctuationist models, very rapid. See also PUNCTUATED EQUILIBRIUM.