Microhabitat and adhesive toepads shape gecko limb morphology

Area of Science:

• Evolutionary Biology
• Comparative Morphology
• Biomechanics

Background:

• Limb morphology in animals is adapted to specific environmental challenges and substrates.
• Gecko adhesive toepads are a key adaptation, but their relationship with limb morphology and microhabitat is not fully understood.

Purpose of the Study:

• To investigate how gecko locomotion is influenced by microhabitat and adhesive toepads.
• To analyze the relationship between gecko limb morphology, microhabitat, and the presence of adhesive toepads.

Main Methods:

• Collected microhabitat and toepad data for over 90% of limbed gecko species.
• Measured limb morphology for 403 species across 83 gecko genera.
• Utilized phylogenetic comparative analyses to assess trait associations.

Main Results:

• Adhesive toepads are associated with arboreality, but this link is not statistically significant, suggesting phylogenetic constraint.
• Pad-bearing geckos exhibit shorter hindlimbs and feet, more uniform limb lengths, and lower crus:thigh ratios compared to padless geckos.
• Saxicolous (rock-dwelling) geckos possess the longest limbs and segments, likely for enhanced stride length and stability on inclines.
• Terrestrial geckos show more even hind- and forelimbs than arboreal geckos, contrasting with patterns in other lizard groups.

Conclusions:

• Microhabitat-morphology relationships vary significantly across taxa due to differing ecologies and evolutionary histories.
• Adhesive toepads represent a key innovation that significantly shapes gecko limb morphology and subsequent locomotion.
• Understanding these evolutionary pathways is crucial for inferring functional morphology from environmental context.