Evolutionary age correlates with range size across plants and animals.

Area of Science:

• Ecology
• Evolutionary Biology
• Conservation Biology

Background:

• Global biodiversity is threatened, with over 40,000 species facing extinction.
• Species range size is a critical factor in extinction risk, yet its determinants are not fully understood.

Purpose of the Study:

• To investigate the relationship between species' age and their current geographic range size.
• To explore how factors like island endemism and dispersal ability influence the age-range size correlation.

Main Methods:

• Analysis of range size and age data for over 26,000 species, including mammals, birds, reptiles, amphibians, reef fishes, and plants.
• Comparative analysis across different taxonomic groups and ecological contexts (islands vs. mainland, dispersal ability).

Main Results:

• Older species, on average, exhibit larger geographic ranges across most studied groups.
• The age-range size relationship is modulated by taxonomic scale, island restriction, and dispersal limitations.
• Species with small ranges and higher extinction risk are often island-bound, poor dispersers, or recently evolved.

Conclusions:

• Species age is a significant predictor of range size, with implications for understanding extinction vulnerability.
• Island biogeography and dispersal capabilities play crucial roles in shaping species' geographic distributions.
• Identifying recently evolved species or those with restricted ranges is vital for targeted conservation efforts.