Similar to allopatric speciation, peripatric speciation involves populations being geographically separated and prevented from exchanging genes. It differs from the allopatric speciation in a way that the population separating from the main population involves a smaller unit.
An example of this is the London Underground mosquito, a variant of the mosquito Culex pipiens, which entered in the London Undgerground in 19th century. Evidence for its speciation includes genetic divergence, behavioural differences, and difficulty in mating.
Word origin: Greek, from peri, around, near + Greek patrā, fatherland.