The Evolution of Rodent Tail Morphology.

Area of Science:

• Evolutionary Biology
• Comparative Anatomy
• Zoology

Background:

• Rodent tail structures are hypothesized to aid in social communication, locomotion, thermoregulation, and predator avoidance.
• The macroevolutionary drivers of rodent tail diversity remain largely unexplored, with limited understanding of how population-level adaptations scale across species.

Purpose of the Study:

• To investigate the macroevolutionary correlates of rodent tail morphology.
• To test established hypotheses regarding tail function and diversity across the order Rodentia.

Main Methods:

• Compiled a database of 11 tail traits for 2,101 rodent species.
• Utilized Bayesian phylogenetic mixed models to analyze evolutionary correlations at the order and suborder levels.

Main Results:

• Tail length correlates with temperature (Allen's rule) and locomotion.
• Black tail tips are associated with brighter environments, naked tails with warmer climates, and fluffy tips with smaller/arboreal species.
• Prehensility is linked to arboreal lifestyles and longer tails; tail autotomy is more common in open environments.

Conclusions:

• Macroevolutionary patterns for some tail traits (e.g., length, color, autotomy) are identified.
• Many predictions from population-level studies are not universally supported across rodent species, highlighting the importance of local ecological context in shaping tail morphology.