Form-function relationships underlie rapid dietary changes in a lizard

Area of Science:

• Evolutionary Biology
• Ecomorphology
• Functional Morphology

Background:

• Macroevolutionary shifts in diet and habitat are linked to adaptive morphological changes.
• The role of small-scale, population-level morphological variation in driving ecological shifts remains unclear.

Purpose of the Study:

• To investigate the relationship between cranial form, feeding mechanics, and diet shifts in an introduced lizard population.
• To understand how microevolutionary morphological variation can influence macroevolutionary ecological changes.

Main Methods:

• Quantified skull shape and jaw muscle architecture differences using 3D geometric morphometrics and dissections.
• Assessed masticatory system mechanical performance via computer-based biomechanical simulations.
• Compared findings with existing macroevolutionary data on insular lizards.

Main Results:

• Identified subtle differences in skull shape and jaw muscle architecture between source and introduced lizard populations.
• Demonstrated that these minor morphological variations significantly enhance feeding performance.
• Showed that improved performance enables access to novel trophic resources.

Conclusions:

• Small-scale morphological variation can drive rapid ecological adaptation and diet shifts.
• Cranial form and muscle architecture variations impact mechanical performance, facilitating access to new resources.
• Provides insights into how natural selection can drive major ecological changes over short timescales.