Neoendemic

Neoendemic is a term used in biogeography and ecology to describe a species whose geographic range is restricted to a small area and whose evolutionary origin is comparatively recent. Neoendemics contrast with paleoendemics, ancient lineages that persist in restricted areas after once being widespread.

Neoendemics arise when populations become reproductively isolated and diverge into distinct species after geographic separation or ecological opportunities. This often occurs in insular environments, mountains, or other isolated habitats where rapid speciation can produce many narrowly distributed endemics in a short time. The designation implies that the species did not exist in its current form for long before becoming geographically confined.

Assessing whether a taxon is a neoendemic involves comparing genetic divergence times with the geological history of the area, sometimes aided by fossil records. Neoendemics can remain highly specialized and vulnerable to habitat loss, making them conservation priorities in regions with limited habitats, such as oceanic islands, archipelagos, or fragmented mountain systems.

Examples often cited include endemic plants and animals on oceanic islands where recent radiations occurred, such as some island endemics in Hawaii and the Canary Islands. However, the exact age of many so-called neoendemics remains debated among scientists.

See also: endemism, paleoendemic, island biogeography.