Does shape co-variation between the skull and the mandible have functional consequences? A 3D approach for a 3D...

Area of Science:

• Evolutionary biology
• Comparative anatomy
• Biomechanics

Background:

• Phenotypic diversity is driven by morpho-functional patterns, crucial for fitness.
• Skull and mandible modularity is well-studied, but their shape co-variation remains underexplored.
• The skull and mandible, though developmentally distinct, function as an integrated unit.

Purpose of the Study:

• To investigate shape co-variation between the skull and mandible in the greater white-toothed shrew.
• To utilize 3D geometric morphometrics for detailed analysis of skull and mandible form.
• To explore the functional consequences of observed shape co-variation patterns.

Main Methods:

• Employed 3D surface geometric morphometric methods to analyze skull and mandible complexity.
• Utilized two-block partial least-squares to describe shape co-variation between the two structures.
• Developed a 3D biomechanical model to assess functional implications of co-variation.

Main Results:

• The 3D morphometric approach effectively captured complex morpho-functional patterns.
• Shape co-variation between skull and mandible revealed functional relationships mediated by jaw adductor muscles.
• Identified direct functional consequences of shape co-variation on muscle recruitment during biting.

Conclusions:

• 3D geometric morphometrics is efficient for studying complex morpho-functional patterns.
• Skull-mandible shape co-variation is functionally significant, influencing feeding biomechanics.
• This study enhances understanding of integrated craniofacial evolution and function.