Chapter 18 - Secular change

Abstract

This chapter considers the effect of secular change on metric and nonmetric sex estimation. Secular changes are biological changes that occur over decades or generations, usually attributed to environmental factors. Secular changes in the human skeletal form over the past two centuries include earlier skeletal maturation; a higher and narrower cranial vault; narrower face; longer cranial base; more gracile pelvis; and longer, narrower, and more gracile long bones. The data and analyses presented here indicate that the approaches may be suitable for forensic applications, but not without re-calibrating equations using modern data and adjusting sectioning points to account for the effects of secular change on skeletal form. If the goal is to facilitate the identification of unknown remains by establishing the most accurate biological profile from the available skeletal data, then best practice necessitates evaluating the short-term effects of the environment on skeletal morphology and revising equations as the data indicates.