Neoendemismi

Neoendemismi is a biogeographical and evolutionary concept that describes endemism arising from relatively recent evolutionary events, leading to species or lineages with a geographically restricted distribution. It is typically contrasted with paleoendemism, where ancient lineages persist in limited areas, often in relic habitats. Neoendemism emphasizes ongoing or very recent diversification rather than ancient persistence.

Neoendemic lineages usually originate through recent speciation in isolated habitats or after colonization of restricted environments such as islands, isolated mountain ranges, or refugial zones. The result is a set of taxa with narrow geographic ranges and, often, specialized ecological requirements. Neoendemics are frequently associated with island biotas or highly fragmented landscapes where barriers to dispersal promote divergent evolution and the formation of new endemics.

Characteristics of neoendemics include small geographic ranges, relatively small population sizes, and high sensitivity to environmental change. Because their distributions are limited, neoendemics are commonly considered vulnerable to habitat loss, climate change, invasive species, and stochastic events. They are frequently the focus of conservation priorities and biogeographical studies.

Assessing whether endemism is neo- or paleo-oriented relies on phylogenetic analyses and molecular dating to estimate divergence times, along with distribution data. However, the distinction is not universal; some taxa may be reclassified as neoendemics as new genetic or fossil information becomes available. The concept remains a useful framework for understanding patterns of diversification, isolation, and conservation value in regions with restricted biotas.