peripatrik

Peripatrik is a term used in evolutionary biology to describe a mode of speciation where a new species evolves from an isolated peripheral population. This process is distinct from sympatric speciation, where new species arise within the same geographic area, and allopatric speciation, where populations are separated by a physical barrier. In peripatric speciation, a small group of individuals from a larger population becomes geographically isolated at the edge of the species' range.

This isolation is crucial because the peripheral population is often small and may experience genetic drift more strongly than the parent population. Genetic drift, the random fluctuation of gene frequencies, can lead to rapid genetic divergence. Furthermore, the peripheral population may encounter different environmental pressures, leading to natural selection favoring distinct traits. These factors, acting together, can result in reproductive isolation between the peripheral population and the ancestral population. If this reproductive isolation becomes complete, the peripheral population will have evolved into a new species.

The founder effect is often invoked in peripatric speciation. This occurs when a new population is established by a very small number of individuals, who may not carry the full genetic diversity of the parent population. Consequently, the genetic makeup of the new population can differ significantly from the original one due to this limited gene pool. Peripatric speciation is considered a form of microallopatric speciation, emphasizing the small scale of the geographic separation.