neoendemism

Neoendemism is a pattern of endemism in which new species have evolved relatively recently and remain geographically restricted to a small area. Neoendemics arise when speciation occurs in isolation or within a confined region, producing lineages that are endemic to that area.

Neoendemics are contrasted with paleoendemics, ancient species that persist in restricted areas as relicts of once-wider distributions. While paleoendemics reflect historical contractions, neoendemics reflect ongoing or recent diversification, typically in isolated ecosystems such as islands, mountain tops, or lakes.

Common contexts include island archipelagos, isolated lakes, and other fragmented habitats where rapid diversification generates multiple endemics. Notable examples often cited in discussions of neoendemism include Darwin’s finches of the Galápagos, the Hawaiian silversword alliance, and African cichlids in Rift Lakes. Plant radiations in regions like the Cape Floristic Region are also cited as neoendemic patterns, reflecting recent lineage splitting within confined geographic spaces.

Implications: neoendemics can be highly vulnerable to extinction due to their restricted ranges, making them a focus of conservation concern. Determining whether a taxon is neoendemic requires phylogenetic and biogeographic evidence to establish a recent origin and limited distribution. Conservation planning often emphasizes protecting habitats that support ongoing speciation and localized endemism.