There and Back Again: A Palaeodemographic Tale of Biased Skeletal Samples

Abstract

Palaeodemography, the study of past human populations, through archaeological skeletal samples has so far relied on reasonable demographic representation for empirical measures such as fertility. Palaeodemographic methods for measuring fertility rely on this representation, particularly the pre-adults in a respective age-at-death distribution. While it is commonly accepted that bioarchaeological samples have a degree of under-representation of pre-adults, the extent of this bias remains unknown without prior knowledge of fertility, particularly when accounting for the myriad factors contributing to sample bias. Subsequently, this creates a further unknown regarding how one can measure and determine whether empirical palaeodemography is applicable to some skeletal samples. This thesis aims to demonstrate how empirical palaeodemography may be achieved for bioarchaeological samples with pre-adult under-representation by exploring how alternative proportions of the age-at-death distribution may be utilised. The proportion of reproductive aged individuals (i.e. D15-49) in an adult-only sample (i.e. D15+) is illustrated to provide a reasonable estimate for total fertility rate, allowing for an empirically derived palaeodemographic measure which does not require pre-adults. Based on the hypothesis that pre-adult representation cannot be determined without prior knowledge of fertility, the coordinated use of the D15-49/D15+ model for estimating fertility and the previously developed D0-14/D model is demonstrated to provide a method for detecting possible bias within an age-at-death distribution. These innovative tools are then applied to skeletal samples from Early Anglo-Saxon England as a mechanism for measuring fertility in changing populations while also exploring the pre-adult representation within these cemeteries. These applications highlight the use of these tools for more difficult bioarchaeological contexts where representation has been questioned and limited empirical palaeodemography has been conducted. Furthermore, this thesis demonstrates how empirical measures of fertility may still be applied to bioarchaeological samples where bias is detected, rather than excluding them altogether. This subsequently opens palaeodemographic research to a broader range of samples for application while also providing the initial steps for expanding the use of these methodologies for deeper interpretation of past populations. Show more