Size and shape differences among six South American Indian tribes

Area of Science:

• Physical Anthropology
• Population Genetics
• Bioanthropology

Background:

• Understanding human population diversity is crucial in anthropology.
• Morphological and genetic variations can reflect evolutionary and migration histories.

Purpose of the Study:

• To compare morphological distances among South American Indian tribes.
• To investigate the relationship between morphological variation, linguistic differentiation, and geographic distance.
• To analyze the contributions of size and shape to intertribal morphological variation.

Main Methods:

• Collected anthropometric measurements (height, head breadth, etc.) from six South American Indian tribes.
• Calculated Mahalanobis's morphological distances, partitioning them into size and shape components.
• Correlated morphological distances with linguistic differentiation and geographic distances.
• Compared morphological distances with distances derived from blood polymorphism data.

Main Results:

• Morphological distances showed a significant correlation with linguistic differentiation.
• No significant correlation was found between morphological distances and geographic distances.
• Shape variation accounted for approximately three times more intertribal variation than size.
• Morphological distances did not correlate well with distances based on blood polymorphisms.

Conclusions:

• Linguistic differentiation appears to be a better indicator of morphological variation among these tribes than geographic proximity.
• Physical shape is a more significant factor than overall size in differentiating these South American Indian populations.
• Morphological and genetic distances may not always align, suggesting complex population dynamics.