How may allopatric and sympatric speciation be distinguished? (4 marks)

First it is important to establish what a species is. A species is a population of similar organisms that can interbreed to produce fertile offspring; meaning they are reproductively isolated from other such populations.Speciation is the formation of new species over the course of evolution. Allopatric and sympatric speciation are two of the key mechanisms through which this is achieved.Allopatric speciation occurs due to populations occupying different geographical areas. Hence there is no gene flow between the populations. (2 marks)By contrast, sympatric speciation is where the populations occupy the same geographical locality; but gene flow is restricted between the populations (2 marks).