Multivariate apportionment of global human craniometric diversity

Area of Science:

• Anthropology
• Human Evolution
• Bioarchaeology

Background:

• Human genetic diversity is primarily found within local populations, with limited regional differentiation.
• Previous studies suggested limited regional selection pressures on cranial morphology, mirroring genetic patterns.

Purpose of the Study:

• To re-evaluate human cranial diversity using advanced statistical methods.
• To investigate the role of interregionally differing selection pressures in shaping cranial variation.
• To assess implications for understanding prehistoric human populations.

Main Methods:

• Principal Components Analysis (PCA) of Mosimann shape variables for cranial data.
• Independent partitioning of cranial variation.
• Comparison of craniometric differentiation estimates with genetic diversity data.

Main Results:

• Cranial variation partitioning revealed interregional differentiation estimates larger than most neutral genetic loci.
• Some cranial features, especially nasal morphology, show differentiation patterns consistent with differing selection pressures.
• Craniometric differentiation estimates align with genetic loci where selection is implicated.

Conclusions:

• Interregionally differing selection pressures contribute to human cranial diversity, particularly in facial features like the nose.
• These findings challenge previous assumptions about limited selection shaping cranial morphology.
• The results have significant implications for interpreting biological affinities in ancient human remains.