A systems-model for the morphological analysis of integration and modularity in human craniofacial evolution

Area of Science:

• Craniofacial Biology
• Evolutionary Biology
• Developmental Biology

Background:

• Craniofacial biology research has a long history.
• The influence of developmental cascades between the brain, cranial base, and face on skull evolution and variation is not fully understood.

Purpose of the Study:

• To discuss craniofacial morphology using a systems model of integration and modularity.
• To analyze morphological variation and evolution of the human skull by considering local and general factors.

Main Methods:

• Proposes a systems model for analyzing human craniofacial morphology.
• Considers ontogenetic and evolutionary modifications of modules by local (cranial) and general (non-cranial) factors.
• Adopts an organismal view on human skull evolution.

Main Results:

• Brain lobe size and shape locally affect skull shape, influencing basicranial morphology.
• These effects interact with mandible position and ethmo-maxillary complex morphology.
• Nasal cavity changes represent a local factor, but are integrated with general systems like respiration and body energetics.

Conclusions:

• A joint consideration of local and general factors is crucial for developing holistic hypotheses on human craniofacial evolution.
• The proposed systems model offers a framework for understanding complex craniofacial development and evolution.
• This approach emphasizes an integrated, organismal perspective on skull evolution.