skip to main content

Title: Using a multimethod life history approach to navigate the osteological paradox: A case study from Prehispanic Nasca, Peru
Abstract Objectives

We leverage recent bioarchaeological approaches and life history theory to address the implications of the osteological paradox in a study population. The goal of this article is to evaluate morbidity and mortality patterns as well as variability in the risk of disease and death during the Late Intermediate period (LIP; 950–1450 C.E.) in the Nasca highlands of Peru. We demonstrate how the concurrent use of multiple analytical techniques and life history theory can engage the osteological paradox and provide salient insights into the study of stress, frailty, and resilience in past populations.

Materials and methods

Crania from LIP burial contexts in the Nasca highlands were examined for cribra orbitalia (n = 325) and porotic hyperostosis (n = 270). All age groups and both sexes are represented in the sample. Survivor/nonsurvivor analysis assessed demographic differences in lesion frequency and severity. Hazard models were generated to assess differences in survivorship. The relationship between dietary diversity and heterogeneity in morbidity was assessed using stable δ15N and δ13C isotope values for bone collagen and carbonate. One hundred and twenty‐four crania were directly AMS radiocarbon dated, allowing for a diachronic analysis of morbidity and mortality.


The frequency and expression of both orbital and vault lesions increases significantly during the LIP. Survivor/nonsurvivor analysis indicates cranial lesions co‐vary with frailty rather than robusticity or longevity. Hazard models show (1) decreasing survivorship with the transition into the LIP, (2) significantly lower adult life expectancy for females compared to males, and (3) individuals with cranial lesions have lower survivorship across the life course. Stable isotope results show very little dietary diversity. Mortality risk and frequency of pathological skeletal lesions were highest during Phase III (1300–1450 C.E.) of the LIP.


Results provide compelling evidence of increasing physiological stress and mortality in the Nasca highlands during the LIP, but also reveal substantial heterogeneity in frailty and the risk of death. Certain members of society experienced a heavier disease burden and higher mortality compared to their contemporaries. Elevated levels of disease and lethal trauma among females account for some of the sex differences in survivorship but cannot explain the large degree of female‐biased mortality. We hypothesize that parental investment in males or increased female fertility rates may explain these differences.

more » « less
Author(s) / Creator(s):
 ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
American Journal of Physical Anthropology
Page Range / eLocation ID:
p. 816-833
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Kuzawa, Chris (Ed.)

    One of the most well-known yet least understood aspects of the 1918 influenza pandemic is the disproportionately high mortality among young adults. Contemporary accounts further describe the victims as healthy young adults, which is contrary to the understanding of selective mortality, which posits that individuals with the highest frailty within a group are at the greatest risk of death. We use a bioarchaeological approach, combining individual-level information on health and stress gleaned from the skeletal remains of individuals who died in 1918 to determine whether healthy individuals were dying during the 1918 pandemic or whether underlying frailty contributed to an increased risk of mortality. Skeletal data on tibial periosteal new bone formation were obtained from 369 individuals from the Hamann–Todd documented osteological collection in Cleveland, Ohio. Skeletal data were analyzed alongside known age at death using Kaplan–Meier survival and Cox proportional hazards analysis. The results suggest that frail or unhealthy individuals were more likely to die during the pandemic than those who were not frail. During the flu, the estimated hazards for individuals with periosteal lesions that were active at the time of death were over two times higher compared to the control group. The results contradict prior assumptions about selective mortality during the 1918 influenza pandemic. Even among young adults, not everyone was equally likely to die—those with evidence of systemic stress suffered greater mortality. These findings provide time depth to our understanding of how variation in life experiences can impact morbidity and mortality even during a pandemic caused by a novel pathogen.

    more » « less
  2. Abstract Objectives

    The developmental origins of health and disease (DOHaD) hypothesis describes how early childhood stress affects morbidity and mortality later in life. The role of early childhood stress in mortality from infectious disease is understudied. Stressors in early childhood that weaken the immune system may result in increased susceptibility to infectious disease in adulthood. Weaning is one of the earliest potential periods of significant stress in early childhood. This research investigates the effect of weaning after ~6 months of age on cholera mortality among 18th–19th‐century Italian populations by determining if earlier breastfeeding cessation is associated with earlier mortality, analyzing childhood dietary variation and physiological stress markers, and determining if age‐at‐weaning completion differs between catastrophic and attritional populations.


    Serial dentin stable carbon and nitrogen isotope analyses from canines are compared between catastrophic (n = 45) and attritional groups (n = 23). Canines are sectioned serially from crown to apex, and the increment's δ15N and δ13C are used to estimate age‐at‐weaning completion.


    Catastrophic and attritional groups exhibit similar age‐at‐weaning completion (~2.8 years). Seventy‐four percent of individuals lack elevated δ15N values in dentin that formed during infancy.


    Age‐at‐weaning completion was not a predisposing factor in cholera mortality in adulthood in this sample. Age‐at‐weaning completion may not be significantly associated with infectious disease mortality because weaning completion likely occurred after infants had adapted to consuming contaminated weanling foods. Individuals without detectable weaning curves may represent infants who received supplementary foods since birth or were weaned before the age of 6–9 months.

    more » « less
  3. Abstract Objectives

    This study provides a comprehensive analysis of crypt fenestration enamel defects (CFEDs) from the Eten and Mórrope communities, Colonial period (A.D. 1,530–1,750), Lambayeque Valley, Peru. The goal is to help clarify the role of these lesions as reflections of early life environments as well as relationships growth and survival at future ages.

    Materials and methods

    CFED absence/presence was recorded in the mandibular canines of 105 individuals and 202 teeth. Defect prevalence was compared between the Eten and Mórrope sites using a proportions test. Femoral growth residuals were compared between CFED present and absent samples. Mortality risk was evaluated using Kaplan–Meier survival analysis.


    CFED frequencies at Eten and Mórrope were similar to previous studies. Greater frequencies of CFEDs were found at Eten compared to Mórrope. There was no association between skeletal growth and CFEDs. No differences in mortality were found between CFED present and absent individuals within each site. General survivorship at Eten was significantly greater than Mórrope. However, individuals without CFEDs at Eten had greater survivorship than those with and without CFEDs at Mórrope. Individuals with CFEDs at Eten had greater survivorship than those with CFEDs at Mórrope. These differences begin around 1.7 years.


    CFEDs may be associated with stress experience, but associations with growth and survivorship at later ages is context dependent. CFED prevalence is an ambiguous indicator of stress when used in the absence of mortality data, and even under those circumstances, appears limited by differences in local demography.

    more » « less
  4. Abstract Objectives

    Dental plaque is associated with a variety of systemic diseases and mortality risks in living populations. However, bioarchaeologists have not fully investigated the mortality risks associated with plaque (or its mineralized form, calculus) in the past. This study examines the relationship between survivorship and calculus in a medieval skeletal sample.

    Materials and methods

    Our sample (n = 1,098) from four medieval London cemeteries,c. 1000–1540 CE, includes people who died under attritional (normal) and catastrophic (famine and plague) conditions. The associations between age and the presence of dental calculus on the permanent left first mandibular molar are assessed using binary logistic regression and Kaplan–Meier survival analysis.


    The regression results indicate a significant negative relationship between age and calculus presence for individuals of all ages who died under normal mortality conditions and for adults who died under both normal and catastrophic conditions. Survival analysis reveals decreased survivorship for people of all ages with calculus under normal mortality conditions. Similarly, during conditions of catastrophic mortality, adult males with calculus suffered reduced survivorship compared to males without it, though there was no difference in survivorship between adult females with and without calculus.


    These results suggest that, as in modern populations, calculus accumulation in the inhabitants of medieval London reflects a greater risk of premature death. The evaluation of calculus, a potential measure of underlying frailty, in the context of a demographic measure of general health suggests that it might provide insights into health in past populations.

    more » « less
  5. Abstract Objectives

    Bioarchaeologists interpret skeletal stress as evidence of resilience or frailty, where absence of lesions might result from lack of exposure to pathogens (i.e., good health) or extreme vulnerability (i.e., selection). We examine physiological stress in two skeletal series from Greek Himera: (1) nine mass graves from the battles of Himera (480 and 409 BCE) and (2) Himeran civilians (648‐409 BCE). Civilians are assumed to have died from multiple causes, including ill health leading to their deaths. Individuals from the battles presumably died while in relatively good health, in battle. More skeletal stress among civilians than battle casualties would support the idea that skeletal stress is a sign of frailty at Himera. We compare variation in skeletal stress between and among civilians and battle casualties.

    Materials and methods

    Cribra orbitalia, porotic hyperostosis, linear enamel hypoplasia (LEH), and sub‐periosteal new bone formation, were examined in 474 individuals (mass gravesn = 64; civiliansn = 410).


    Chi‐square tests showed significantly higher prevalence of LEH (p = 0.04) and sub‐periosteal new bone formation (p = 0.05) among young and mid‐aged adult male civilians than mass grave casualties. Skeletal stress was also lower in the earlier battle, and varied among civilians with burial style.


    Our findings generally support the hypothesis that skeletal stress is evidence of frailty (i.e., leading to greater risk of mortality). However, the relationship between stress and frailty is complicated by social factors, when considering historical context. In particular, a possible “soldier‐class” may have experienced less stress than the overall civilian population.

    more » « less