Evolutionary applications of phylogenetically-informed ecological niche modelling (ENM) to explore cryptic...

Area of Science:

• Ecology
• Evolutionary Biology
• Genetics

Background:

• The Hyrcanian Forests, an ancient temperate deciduous forest, is a crucial area for understanding biodiversity.
• Cryptic diversification, the process by which previously unrecognized species evolve, is poorly understood in many forest ecosystems.
• The fat dormouse (Glis glis) serves as a model organism to study diversification patterns in this unique environment.

Purpose of the Study:

• To investigate the phylogenetic status of fat dormouse populations in the Hyrcanian Forests.
• To determine if niche divergence supports cryptic diversification in Glis glis.
• To assess the role of the Hyrcanian Forests as a potential Pleistocene refugium for cryptic species.

Main Methods:

• Mitochondrial Cytochrome b (Cytb) DNA sequencing was employed to reconstruct phylogenetic relationships.
• Phylogenetically informed occurrence data was analyzed using two distinct Ecological Niche Models (ENMs): environmental-space and geographic-space.
• Niche divergence and conservatism were quantified using the ENM frameworks.

Main Results:

• Phylogenetic analysis revealed significant genetic heterogeneity among fat dormouse lineages, including distinct groups within the Hyrcanian Forests.
• The two ENM frameworks confirmed niche divergence between the two identified cryptic lineages.
• Evidence of niche conservatism was observed, supporting the distinct evolutionary trajectories of these lineages.

Conclusions:

• The study confirms the presence of distinct cryptic species of fat dormice within the Hyrcanian Forests.
• The findings suggest that the Hyrcanian Forests, a known Pleistocene refugium, may harbor multiple cryptic refugia for small forest-dwelling species.
• This highlights the importance of ancient forest ecosystems in promoting and preserving hidden biodiversity during past climate oscillations.