Using the life history model to set the stage(s) of growth and senescence in bioarchaeology and paleodemography

Abstract

Paleodemography, the study of demographic parameters of past human populations, relies on assumptions including biological uniformitarianism, stationary populations, and the ability to determine point age estimates from skeletal material. These assumptions have been widely criticized in the literature and various solutions have been proposed. The majority of these solutions rely on statistical modeling, and have not seen widespread application. Most bioarchaeologists recognize that our ability to assess chronological age is inherently limited, and have instead resorted to large, qualitative, age categories. However, there has been little attempt in the literature to systematize and define the stages of development and ageing used in bioarchaeology. We propose that stages should be based in the human life history pattern, and their skeletal markers should have easily defined and clear endpoints. In addition to a standard five-stage developmental model based on the human life history pattern, current among human biologists, we suggest divisions within the adult stage that recognize the specific nature of skeletal samples. We therefore propose the following eight stages recognizable in human skeletal development and senescence: infancy, early childhood, late childhood, adolescence, young adulthood, full adulthood, mature adulthood, and senile adulthood. Striving toward a better prediction of chronological ages will remain important and could eventually help us understand to what extent past societies differed in the timing of these life stages. Furthermore, paleodemographers should try to develop methods that rely on the type of age information accessible from the skeletal material, which uses life stages, rather than point age estimates.

Subsistence strategy changes: The evidence of entheseal changes

“…However, the methods for ageing skeletons are not good at identifying older individuals. Further analysis on identified skeletal collections is needed to determine whether using a cut-off at young adult (defined as per Roksandic and Armstrong, 2011) reduces the impact of degenerative processes, thus allowing activity-patterns to be analysed. Another method to reduce the effect of age is to study bilateral asymmetry within individuals (Villotte pers.…”

A Test of Hartnett's Revisions to the Pubic Symphysis and Fourth Rib Methods on a Modern Sample

“…Both the Suchey-Brooks and _ Is ßcan et al methods are based on phase systems with descriptions of the degenerative changes occurring at each phase, and both have comparative casts available for purchase. Overall, researchers tend to agree that these methods are sufficiently accurate; however, many studies have found sampling issues, discrepancies in the statistical models used to create the methods, and high rates of inter-and intra-observer error (16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30).…”

Starch analysis and isotopic evidence of consumption of cultigens among fisher–gatherers in Cuba: the archaeological site of Canímar Abajo, Matanzas

“…Sex was assessed using standard morphometric methods for pelvic, cranial, and postcranial remains (Bruzek, 2002;Buikstra and Ubelaker, 1994). Age was assessed as a developmental/senescence stage (Roksandic and Armstrong, 2011). Forty-five (45) of the Canímar Abajo adults (femur samples from 14 OC and 31 YC individuals) were processed for carbon and nitrogen isotope analyses (Table 1).…”