Sympatric speciation

Sympatric speciation, unlike allopatric speciation, does not require large-scale geographic distance to reduce gene flow between parts of a population. Merely exploiting a new niche may automatically reduce gene flow with individuals exploiting the other niche. This may occasionally happen when, for example, herbivorous insects try out a new host plant. The question of whether speciation can occur in sympatry has been among the most contentious in evolutionary biology. In recent years a growing number of studies have provided empirical evidence that it has occurred