Urban and rural mortality and survival in Medieval England

Adult mortality in the metropolis of London 1100-1850: A Bayesian view based on osteological data

OBJECTIVES

The present paper highlights the potential of osteological data for answering demographic questions through the development and application of a Bayesian approach incorporating age estimations of adults.

MATERIALS AND METHODS

The metropolis of London is a rewarding study region for such an approach due to the large number of cemeteries, with thousands of individuals, spanning a period from 1100 AD to the mid-19th century, that have been excavated and published in the past two decades. Furthermore, London has a rich tradition of early written records on mortality that can be used for comparison purposes. In order to gain comparable results from the different source categories, we use a Bayesian framework in which the Gompertz distribution features centrally.

RESULTS

Our intensive simulations show that the Bayesian approach performs better than maximum likelihood estimation or ordinary least squares in terms of recovering the original age distribution parameters. They also show how strongly population growth affects mortality patterns. The osteological data suggests that during medieval times and the Early Modern period, the modal age-at-death of the general population of London remained more or less constant and hovered around 30 years, and that only monks showed a higher modal age, of about 45 years. However, from the 17th century onwards, life expectancy of adults increased markedly.

DISCUSSION

Our comparison of written sources and osteological data demonstrates their general comparability and highlights the much higher mortality among adults in London than in the rest of England and Wales. We conclude that Bayesian modeling has great potential for recovering true mortality patterns from osteological data.

Disability and care in Western Europe during Medieval times: A bioarchaeological perspective

This Special Issue has its foundation in presentations delivered in the symposium Disability and Care in Medieval Times: a Bioarchaeological Perspective into Health-related Practices held at the 2019 European Association of Archaeologists conference in Switzerland. It comprises 12 papers, all relevant to aspects of pathology experience and/or care provision in Western Europe during the Early to Late Middle Ages (500 - 1500 CE). Reflecting the 1000 year timespan involved, these papers are characterised by diversity in subject matter and in the lifeways in which they are located, but all contribute to the symposium's primary aim: to demonstrate that our understanding of the Medieval period is enhanced by cross-disciplinary, bioarchaeological research into individual and collective experiences of disability and care. This Introduction provides the background to the 2019 symposium, and briefly discusses the papers contained in the Special Issue which emerged from this.

Frailty and survival in the 1918 influenza pandemic

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.

Contextualizing bilateral asymmetry and gender: A multivariate approach to femoral cross-sectional geometry at rural Medieval Pieve di Pava, Italy

OBJECTIVES

Our objective was to identify the relationship between biocultural factors of sex-gender and age and patterns of femoral cross-sectional geometry with historical evidence about labor and activity from an archeological skeletal sample excavated from the rural Medieval site Pieve di Pava.

MATERIALS AND METHODS

The study site, Pieve di Pava, was a rural parish cemetery in Tuscany with osteoarcheological remains from the 7th to 12th centuries. Cross-sectional geometric analysis of femora from 110 individuals dated to the 10th-12th centuries were used to examine trends in bone quantity, shape, and bending strength between age and sex groups, as well as in clusters identified through Hierarchical Cluster Analysis (HCA).

RESULTS

Overall, our study sample showed remarkable heterogeneity and our cluster analysis revealed a complex underlying structure, indicating that divisions of labor did not follow a strict gender binary in our sample. We found high levels of bilateral asymmetry in our sample in multiple cross-sectional areas for a significant proportion of the population. We found minimal differences between age groups or sex.

DISCUSSION

Our results suggest that males and females had varied experiences of labor and work during their lives that did not reflect the strict binary gender roles sometimes documented for medieval Europe. One important axis of difference is the direction and magnitude of bilateral asymmetry observed in our femur sample, which is associated with divergent trends in section moduli and bone area measures.

Twenty-first century bioarchaeology: Taking stock and moving forward

This article presents outcomes from a Workshop entitled "Bioarchaeology: Taking Stock and Moving Forward," which was held at Arizona State University (ASU) on March 6-8, 2020. Funded by the National Science Foundation (NSF), the School of Human Evolution and Social Change (ASU), and the Center for Bioarchaeological Research (CBR, ASU), the Workshop's overall goal was to explore reasons why research proposals submitted by bioarchaeologists, both graduate students and established scholars, fared disproportionately poorly within recent NSF Anthropology Program competitions and to offer advice for increasing success. Therefore, this Workshop comprised 43 international scholars and four advanced graduate students with a history of successful grant acquisition, primarily from the United States. Ultimately, we focused on two related aims: (1) best practices for improving research designs and training and (2) evaluating topics of contemporary significance that reverberate through history and beyond as promising trajectories for bioarchaeological research. Among the former were contextual grounding, research question/hypothesis generation, statistical procedures appropriate for small samples and mixed qualitative/quantitative data, the salience of Bayesian methods, and training program content. Topical foci included ethics, social inequality, identity (including intersectionality), climate change, migration, violence, epidemic disease, adaptability/plasticity, the osteological paradox, and the developmental origins of health and disease. Given the profound changes required globally to address decolonization in the 21st century, this concern also entered many formal and informal discussions.

Paleodemography: From archaeology and skeletal age estimation to life in the past

Much of paleodemography, an interdisciplinary field with strong ties to archaeology, among other disciplines, is oriented toward clarifying the life experiences of past people and why they changed over time. We focus on how human skeletons contribute to our understanding of preindustrial demographic regimes, including when changes took place that led to the world as we know it today. Problems with existing paleodemographic practices are highlighted, as are promising directions for future work. The latter requires both better age estimates and innovative methods to handle data appropriately. Age-at-death estimates for adult skeletons are a particular problem, especially for adults over 50 years that undoubtedly are mistakenly underrepresented in published studies of archaeological skeletons. Better age estimates for the entirety of the lifespan are essential to generate realistic distributions of age at death. There are currently encouraging signs that after about a half-century of intensive, and sometimes contentious, research, paleodemography is poised to contribute much to understandings of evolutionary processes, the structure of past populations, and human-disease interaction, among other topics.

Abandonment of the Middle Cumberland Region of Tennessee during the Mississippian period: Temporal and sex differences in survivorship

OBJECTIVES

The current research explores survivorship differences in the Middle Cumberland Region of Tennessee during the Mississippian period (ca. 1000-1500 AD). Using updated paleodemographic methods, this study investigates whether individuals from the Late Mississippian period had lower survivorship compared to individuals from the Early Mississippian period, foreshadowing groups on the brink of abandonment. Additionally, this study examines whether there were sex disparities in survivorship.

MATERIALS AND METHODS

Adult age-at-death estimates from human skeletal remains (n = 545) were calculated using Transition Analysis, a Bayesian maximum likelihood method. Survivorship was reconstructed using Gompertz and Gompertz-Makeham hazards models, with Akaike Information Criterion compared to determine the best fitting model.

RESULTS

For individuals surviving into adulthood, mean age-at-death decreased by 7 years from the Early Mississippian to Late Mississippian period. Marked differences between the sexes indicate lower survivorship of females compared to males. Male survivorship decreased sharply from the Early Mississippian to Late Mississippian period, from a mean age-at-death of 57.99 years to 44.45 years. Female survivorship remained constant throughout the Mississippian period (41 years).

DISCUSSION

Temporal differences in male survivorship may be the result of interactions between climate change, decreased maize harvests, and sociopolitical strife. Sustained maternal mortality may have destabilized small-scale communities that characterized the Mississippian MCR, thereby precipitating population decline.

Toward a bioarchaeology of urbanization: Demography, health, and behavior in cities in the past

Urbanization is one of the most important settlement shifts in human history and has been the focus of research within bioarchaeology for decades. However, there have been limited attempts to synthesize the results of these studies in order to gain a broader perspective on whether or how urbanization affects the biology, demography, and behavior of humans, and how these potential effects are embodied in the human skeleton. This paper outlines how bioarchaeology is well-suited to examine urbanization in the past, and we provide an overview and examples of three main ways in which urbanization is studied in bioarchaeological research: comparison of (often contemporaneous) urban and rural sites, synchronic studies of the variation that exists within and between urban sites, and investigations of changes that occur within urban sites over time. Studies of urbanization, both within bioarchaeology and in other fields of study, face a number of limitations, including a lack of a consensus regarding what urban and urbanization mean, the assumed dichotomous nature of urban versus rural settlements, the supposition that urbanization is universally bad for people, and the assumption (at least in practice) of homogeneity within urban and rural populations. Bioarchaeologists can address these limitations by utilizing a wide array of data and methods, and the studies described here collectively demonstrate the complex, nuanced, and highly variable effects of urbanization.

An epidemiological approach to the analysis of cribra orbitalia as an indicator of health status and mortality in medieval and post-medieval London under a model of parasitic infection

OBJECTIVES

Many individuals living in medieval and post-medieval London suffered issues with sanitation, food insecurity, infectious disease, and widespread exposure to parasites from a multitude of sources, causing increased risk of death for many inhabitants. We examine this stressful environment and its relationship with various demographic and temporal dimensions, using cribra orbitalia (CO) as an indicator of stress, to model an increased risk of dying under the expectations of our proposed parasitic model of infection.

MATERIALS AND METHODS

We analyze the relationship between CO and mortality across seven medieval and post-medieval cemeteries from London by the covariates of sex, status, and age-at-death. A survival analysis (Cox regression) and a binomial logit estimated hazard and odds ratios of dying with CO across age-at-death, sex, status, and time-period within single statistical models. In addition, we provide new Bayesian age-at-death estimates for post-medieval samples.

RESULTS

The models show the rate of CO decreased over time and age-at-death, regardless of sex or status; post-medieval individuals were ~72% less likely to die with lesions than their medieval counterparts. Further, individuals with CO had ~1% decrease in risk of dying with CO per year of age.

DISCUSSION

These results suggest increased mortality risk for those with lesions indicative of anemia (CO), and selective mortality of younger individuals during the medieval period. Despite sex-specific nutritional and occupational hazards, and status-based access to resources, the prevalence of CO was similar across sex and status, which suggests living with parasitic infection that caused anemia was an everyday reality for medieval and post-medieval Londoners.

A paleodemographic assessment of mortality and fertility rates during the second demographic transition in rural central Indiana

OBJECTIVES

Since its inception, skeletally based paleodemographic research has emphasized the utility of biocultural models for interpreting the dynamic relationship between the sociocultural and ecological forces accompanying demographic transitions and shaping populations' health and well-being. While the demographic transition associated with the Neolithic Revolution has been a common focus in bioarcheology, the present study analyzes human skeletal remains from a large 19th century cemetery in central Indiana to examine population dynamics during the second demographic transition, a period generally characterized by decreasing fertility rates and improvements in life expectancy. This study demonstrates the potential to methodologically identify regional variations in the timing and interactions between broad-scale socioeconomic changes and technological advancements that characterized the time period through observed changes in survivorship and fertility based on age-at-death distributions.

MATERIALS AND METHODS

This study uses three temporally distinct samples (AD 1827-1869; 1870-1889; 1890-1935) from the Bethel Cemetery (n = 503). Kaplan-Meier survival analyses with a log- rank tests are utilized to evaluate survivorship and mortality over time. Next, Cox proportional hazard analyses are employed to examine the interaction between sex and time as covariates. Finally, the D0-14/D ratio is applied to estimate fertility for each of the three temporally bounded cohorts.

RESULTS

The Kaplan-Meier survival analyses and Cox proportional hazard modeling revealed statistically significant differences in survivorship between the three time periods. Age-specific mortality rates are reduced among adult female and male age classes in this rural community over the course of the 19th and early 20th centuries, resulting in the increasing life expectancies associated with the second demographic transition. While mortality in early adulthood was common during the first time period and decreases thereafter, sex was not identified as a meaningful covariate. The proportion of juveniles in the three temporal samples indicate that fertility rates were higher than national averages for the better part of the 19th century and subsequently declined around the turn of 20th century for this community.

CONCLUSIONS

The results indicate temporal differences between the three periods, demonstrating increased survivorship and decreased mortality and fertility over time. These findings corroborate two key features of the second demographic transition characterized by the move from high rates of both fertility and mortality to reduced rates and a general easing of demographic pressures. The observed trends likely reflect improvements in health, coinciding the industrial advance and economic development within and around Indianapolis. While the socioeconomic factors characterizing the Industrial Revolution drove demographic shifts that parallel an equally important epidemiological transition, potential regional differences are discussed to highlight variability in the timing of demographic transitions. The paleodemographic methods utilized in this study demonstrate improved accuracy and efficacy, which ultimately advances researchers' potential to disentangle population-specific socioeconomic factors that may contribute to asymmetrical experiences of health and mortality.

Economic access influences degenerative spine disease outcomes at rural Late Medieval Villamagna (Lazio, IT)

OBJECTIVES

Degenerative joint disease in the spine is heavily influenced by genetic, environmental, and epigenetic factors, as well as exacerbated by physical activity and injury. The objective of this study was to investigate the multivariate relationship between known predictors of degenerative joint disease in the spine, such as age and sex, with mortuary indicators of economic access such as grave inclusions, burial location, and burial type.

MATERIALS AND METHODS

The presence and severity of vertebral osteophytosis (VO) and vertebral osteoarthritis (VOA) was recorded for the vertebral columns of N = 106 adult individuals from the Late Medieval period at the rural monastery of San Pietro at Villamagna in Lazio, Italy (1300-1450 AD). Multiple skeletal indicators of degenerative joint disease, morphological sex, and age were compared with differences in mortuary treatment across four regions of the spine.

RESULTS

There are marked differences in severe joint disease outcome between groups with more and less economic access. Relative risk ratios suggest that males and females with less economic access have elevated risk for VO and VOA in specific spine regions, although this effect is reduced among females.

DISCUSSION

Current research on the consequences of economic and social inequality point to the important role of economic inequality in shaping disease outcomes. Our results suggest that biocultural effects of reduced economic access at the intraclass level may increase vulnerability to the downstream effects of risk exposure (e.g., biomechanical injure, physical activity, biochemical imbalance), and ultimately increase the risk and prevalence for severe degenerative disease outcomes in medieval Italy.

Coming of age in the Netherlands: An osteological assessment of puberty in a rural Dutch post-medieval community

OBJECTIVES

The objective of this study is to apply pubertal stage estimation methods to a sample from a rural community: the post-medieval Dutch skeletal collection from Middenbeemster. Puberty is a key developmental period involving transition to physical adulthood with broad societal relevance through its impact on fertility, morbidity, and mortality.

MATERIALS AND METHODS

Individuals (n = 55), including 27 of known sex and age-at-death, between the ages of 8 and 25 years were assessed for six skeletal markers indicative of pubertal growth spurt. Recent novel osteoarchaeological methods from Shapland and Lewis are used to reconstruct the timing and duration of pubertal stages.

RESULTS

Pubertal acceleration occurred earlier in females (10.38 years, n = 8) than males (13.30 years, n = 6), whereas maturation occurred later in males (21.36 years, n = 11) than females (19.30 years, n = 5). Onset appears earlier and completion later compared to other archaeological skeletal samples with osteoarchaeological evidence of puberty. Age shortly after menarche was reconstructed at 20.45 years, substantially later than historic records and bioarchaeological research reports suggest.

CONCLUSION

This early onset and late completion caused a "stretch" of the overall duration of puberty compared to other collections, especially of the last three stages. This prolonged development is reflected in historically known social expectations for the Netherlands, for example, that marriage and children should not occur before about 22-23 years of age. Increasing the range of past peoples with puberty stage reconstruction will permit more insightful interpretations of the biological and cultural patterns of this important life stage.

Survival analysis of the Black Death: Social inequality of women and the perils of life and death in Medieval London

OBJECTIVES

Described as an indiscriminate killer by many chroniclers, the Black Death descended on London during the 14th century. To best understand the pattern of transmission among demographic groups, models should include multiple demographic and health covariates concurrently, something rarely done when examining Black Death, but implemented in this study to identify which demographic groups had a higher susceptibility. Female predisposition to the Black Death was also explored, focusing on whether social inequality added to vulnerability.

MATERIALS AND METHODS

Three attritional cemeteries from the Wellcome Osteological Research Database were compared with the Black Death cemetery, East Smithfield. A Cox proportional hazards regression estimated hazards ratios of dying of the Black Death, using transition analysis ages-at-death as the time variable, and sex and frailty as covariates. Additionally, a binomial logistic regression generated odds ratios for age-at-death, sex, and frailty.

RESULTS

The Cox model produced a significant hazards ratio for individuals deemed frail. Similarly, the logit model calculated significantly increased odds ratios for frail individuals, and decreased odds for individuals aged 65+.

DISCUSSION

The older individuals were not undergoing growth during times of great stress in London pre-dating the Black Death epidemic, which may explain the decreased odds of contracting the Black Death. Further, although women dealt with social inequality, which partially led to the demographic puzzle of the Medieval "missing" women, women's susceptibility to infection by the Black Death was not increased. The phenomenon of the missing women may be due to a combination of factors, including infant and child mortality and preservation.

Genetic resiliency and the Black Death: No apparent loss of mitogenomic diversity due to the Black Death in medieval London and Denmark

OBJECTIVES

In the 14th century AD, medieval Europe was severely affected by the Great European Famine as well as repeated bouts of disease, including the Black Death, causing major demographic shifts. This high volatility led to increased mobility and migration due to new labor and economic opportunities, as evidenced by documentary and stable isotope data. This study uses ancient DNA (aDNA) isolated from skeletal remains to examine whether evidence for large-scale population movement can be gleaned from the complete mitochondrial genomes of 264 medieval individuals from England (London) and Denmark.

MATERIALS AND METHODS

Using a novel library-conserving approach to targeted capture, we recovered 264 full mitochondrial genomes from the petrous portion of the temporal bones and teeth and compared genetic diversity across the medieval period within and between English (London) and Danish populations and with contemporary populations through population pairwise Φ_ST analysis.

RESULTS

We find no evidence of significant differences in genetic diversity spatially or temporally in our dataset, yet there is a high degree of haplotype diversity in our medieval samples with little exact sequence sharing.

DISCUSSION

The mitochondrial genomes of both medieval Londoners and medieval Danes suggest high mitochondrial diversity before, during and after the Black Death. While our mitochondrial genomic data lack geographically correlated signals, these data could be the result of high, continual female migration before and after the Black Death or may simply indicate a large female effective population size unaffected by the upheaval of the medieval period. Either scenario suggests a genetic resiliency in areas of northwestern medieval Europe.

Frequency and developmental timing of linear enamel hypoplasia defects in Early Archaic Texan hunter-gatherers

Digital photographs taken under controlled conditions were used to examine the incidence of linear enamel hypoplasia defects (LEHs) in burials from the Buckeye Knoll archaeological site (41VT98 Victoria county, Texas), which spans the Early to Late Archaic Period (ca. 2,500-6,500 BP uncorrected radiocarbon). The majority (68 of 74 burials) date to the Texas Early Archaic, including one extremely early burial dated to 8,500 BP. The photogrammetric data collection method also results in an archive for Buckeye Knoll, a significant rare Archaic period collection that has been repatriated and reinterred. We analyzed the incidence and developmental timing of LEHs in permanent canines. Fifty-nine percent of permanent canines (n = 54) had at least one defect. There were no significant differences in LEH frequency between the maxillary and mandibular canines (U = 640.5, n1 = 37, n2 = 43, p = .110). The sample studied (n = 92 permanent canines) had an overall mean of 0.93 LEH defect per tooth, with a median of one defect, and a mode of zero defects. Average age at first insult was 3.92 (median = 4.00, range = 2.5-5.4) and the mean age of all insults per individual was 4.18 years old (range = 2.5-5.67). Age at first insult is consistent with onset of weaning stress-the weaning age range for hunter-gatherer societies is 1-4.5. Having an earlier age of first insult was associated with having more LEHs (n = 54, rho = -0.381, p = 0.005).

The effect of leprotic infection on the risk of death in medieval rural Denmark

INTRODUCTION

Paleopathological studies of leprosy in Danish skeletal collections show that many individuals suffered from this stigmatized disease during the Middle Ages. This study examines the risk of death associated with leprotic infection in individuals from the Danish rural cemetery of Øm Kloster (AD 1172-1536). Specifically, we modeled the influence of leprotic infection on age-specific mortality accounting also for sex and social status (lay person / monastic).

MATERIALS AND METHODS

The sample consisted of 311 adult individuals from the Øm Kloster skeletal collection housed at the Institute of Forensic Medicine, University of Southern Denmark (ADBOU). We modeled morbidity and mortality using a three-state illness-death model with the following parameterizations for the three transition hazards: (1) nonlesioned to lesioned: constant; (2) nonlesioned to dead: Gompertz-Makeham; and (3) lesioned to dead: Gompertz-Makeham, directly proportional to the hazard of the well to dead transition.

RESULTS

The mortality hazard of lesioned individuals exceeded that of nonlesioned individuals by a factor of 1.4 (40%) across all individuals, 1.7 for females, 1.0 for males, 1.3 for lay persons, and 1.7 for monastics. Overall, 15% of the sample died with skeletal manifestations of leprosy, though it is likely that a higher percentage of the population carried the bacterium.

DISCUSSION

This study improves understanding of past health and population dynamics focusing on a chronic infectious disease. The methods employed could informatively be applied to larger analyses of community health from skeletal collections by incorporating more than one disease into the multistate model and inferring individual frailty using various skeletal markers.

Three individuals, three stories, three burials from medieval Trondheim, Norway

This article presents the life stories of three individuals who lived in Trondheim, Norway, during the 13^th century. Based on skeletal examinations, facial reconstructions, genetic analyses, and stable oxygen isotope analyses, the birthplace, mobility, ancestry, pathology, and physical appearance of these people are presented. The stories are discussed within the relevant historical context. These three people would have been ordinary citizens, without any privileges out of the ordinary, which makes them quite rare in the academic literature. Through the study of individuals one gets a unique look into the Norwegian medieval society.