Secular Change in Morphological Pelvic Traits used for Sex Estimation

Area of Science:

• Forensic Anthropology
• Biological Anthropology
• Human Osteology

Background:

• Phenice's morphological traits of the pubis (medial ischio-pubic ramus, subpubic contour, ventral arc) are used for sex estimation.
• Secular changes, or changes over time, in skeletal morphology are a known phenomenon.
• Understanding these changes is crucial for the continued accuracy of forensic identification techniques.

Observation:

• This study compared pubic trait morphology between historical (Hamann-Todd Collection) and modern (Bass Donated Collection) skeletal samples.
• Ordinal scores for three specific pubic traits were analyzed.
• The Freeman-Halton test was employed to detect significant differences in trait frequencies between the temporal groups.

Findings:

• Significant temporal differences in trait frequencies were observed for all three traits in females and for the subpubic contour and ventral arc in males.
• Logistic regression showed low classification accuracy (68.7%) between temporal periods.
• Despite temporal shifts, secular changes enhanced classification accuracy between sexes in modern populations.

Implications:

• Secular changes in pubic morphology are evident and measurable.
• Existing sex estimation methods based on these traits, developed from historical samples, retain applicability in contemporary forensic contexts.
• The observed secular changes may even improve the accuracy of sex estimation in modern populations.