Is salamander arboreality limited by broad-scale climatic conditions?

Area of Science:

• Evolutionary biology
• Macroevolution
• Herpetology

Background:

• Understanding historical drivers of microhabitat transitions is key in evolutionary biology.
• Lungless salamanders (Plethodontidae) exhibit frequent arboreal habitat shifts without significant morphological changes, posing a challenge to identifying transition mechanisms.
• Morphological specialization is not always a prerequisite for understanding microhabitat transitions.

Purpose of the Study:

• To investigate the relationship between microhabitat use and climatic patterns in lungless salamanders.
• To test the hypothesis that climate influences the availability of arboreal microhabitats.
• To explore macroevolutionary patterns shaped by micro-environmental conditions.

Main Methods:

• Phylogenetic comparative methods were used to analyze microhabitat use and climate data.
• Ecological niche modeling was employed to quantify niche overlap between species.
• Species-level pairwise comparisons of niche overlap were conducted, accounting for geographic and phylogenetic distances.

Main Results:

• Arboreal salamander species inhabit warmer, lower elevation areas compared to terrestrial species.
• Ecological niche models showed greater niche overlap among arboreal species than between arboreal and terrestrial species.
• These findings suggest that specific climatic conditions (warm, low elevation) are crucial for arboreal microhabitat occupation.

Conclusions:

• Climate plays a significant role in shaping macroevolutionary patterns of microhabitat use in lungless salamanders.
• The availability of suitable microhabitats, influenced by climate, can drive evolutionary transitions.
• Micro-environmental factors can have substantial, large-scale impacts on evolutionary trajectories.