Craniofacial Secular Change in Recent Mexican Migrants

Area of Science:

• Anthropology
• Bioarchaeology
• Human Biology

Background:

• Recent economic research indicates Mexican migrants possess higher education and socioeconomic status (SES) than earlier migrants.
• Higher SES and education are linked to secular changes in body form, prompting an analysis of craniofacial complex changes.
• Mexican migrants represent a baseline for studying secular change, unaffected by the American environment.

Purpose of the Study:

• To investigate cranial secular changes in recent Mexican migrants.
• To compare craniofacial morphology between historic and recent Mexican migrants.
• To understand secular trends and biological variation within Mexican migrant populations.

Main Methods:

• Analysis of vault and face size, plus 82 craniofacial interlandmark distances.
• Multivariate adaptive regression splines and basis splines for secular trend assessment in recent migrants.
• Partial Least Squares Discriminant Analysis (PLS-DA) to compare historic and recent samples due to unavailable birth dates for the historic group.

Main Results:

• Significant secular changes over time were detected in both male and female recent Mexican migrants.
• PLS-DA achieved 87% classification accuracy, revealing significant morphological differences between historic and recent groups.
• Historic Hispanic samples displayed larger overall craniofacial dimensions compared to recent Mexican migrants.

Conclusions:

• While secular trends are subtle in recent Mexican migrants, significant craniofacial morphological differences exist between historic and recent Mexican populations in the U.S.
• These findings highlight distinct craniofacial patterns between early and recent Mexican groups, informing future research on migrant adaptation and biological variation.