Recent extinctions disturb path to equilibrium diversity in Caribbean bats

Area of Science:

• Ecology
• Evolutionary Biology
• Paleontology

Background:

• Islands are crucial for studying biodiversity changes and human impacts.
• Island biodiversity theory predicts an equilibrium, but recent extinctions challenge this.
• Caribbean bat subfossil records offer a unique dataset for analyzing insular community dynamics.

Purpose of the Study:

• To reconstruct the diversity trajectory of Greater Antillean noctilionoid bats.
• To model colonization, extinction, and speciation dynamics using phylogenetic and paleontological data.
• To assess the impact of anthropogenic extinctions on island biodiversity equilibrium.

Main Methods:

• Applied a dynamic model to phylogenetic and paleontological data.
• Included all known extinct and extant noctilionoid bat species from the Greater Antilles.
• Utilized a metric to quantify island biodiversity loss.

Main Results:

• Species richness in Caribbean bats demonstrates an asymptotic approach to an equilibrium value.
• Recent human-driven extinctions have eliminated approximately one-third of island bat lineages.
• It is estimated that regaining pre-human diversity levels will require at least eight million years.

Conclusions:

• Island communities exhibit natural equilibrium dynamics, as shown by bat species richness.
• Anthropogenic extinctions significantly disrupt natural biodiversity trajectories, leading to evolutionary disequilibrium.
• Human activities have caused substantial and long-lasting biodiversity loss on islands.