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1. Sex‐biased parental investment and female wealth accumulation in ancient California

   https://doi.org/10.1002/ajpa.24806  

   Greenwald, Alexandra M. ; Burns, Gregory R. ; Eerkens, Jelmer W. ; Bartelink, Eric J. ; Leventhal, Alan ; Arellano, Monica V. ( July 2023 , American Journal of Biological Anthropology)

   The mortuary record at Middle Period siteKalawwasa Rummeytak(CA‐SCL‐134) (2600‐1225 cal BP) in California's southern Santa Clara Valley shows pronounced wealth inequality;Olivellashell bead wealth, as well as other grave goods, are concentrated in the burials of several older adult females. The concentration of wealth among women, along with regional strontium isotopic evidence of male‐biased residential shifts in early adulthood, suggests a matrilineal kinship system that practiced matrilocal post‐marital residence patterns. We suggest local resource enhancement effects incentivized keeping women in their natal communities and investing more in female offspring.

   With the consent of, and in collaboration with, the Muwekma Ohlone Tribe of the San Francisco Bay Area, this paper employs isotopic analysis (δ¹⁵N andδ¹³C,⁸⁶Sr/⁸⁷Sr) to examine duration of exclusive breastfeeding, weaning age (complete cessation of breastmilk consumption), early childhood diet, and lifetime residential mobility of individuals interred atKalawwasa Rummeytakto test the assumption that the site inhabitants favored matrilocality and that female offspring received greater levels of investment in groups with female wealth/status attainment. First molars, third molars, and bone was sampled from 22 individuals.

   The average weaning age for females atKalawwasa Rummeytakis 36.3 months ± 9.7 (1 SD), or just over 3 years. The average weaning age for males is 31.2 ± 7.9 months (1 SD), or about 2.6 years. Infants at the site were provisioned with supplemental foods dominated by C₃plants and terrestrial herbivores, as well as anadromous fish. After weaning, individuals consumed a diet dominated by acorns, C₃plants, and terrestrial herbivores, with periodic inclusion of anadromous fish. 30% of the sampled population of females exhibit local first molar⁸⁷Sr/⁸⁶Sr values, suggesting thatKalawwasa Rummeytakis their natal community. None of the males interred at the site are locals.

   Despite the small sample size often unavoidable in archaeological contexts, we find possible female‐biased parental investment strategies. Cessation of breastfeeding (weaning) was, on average, 5 months earlier for males compared to females. There are no differences between females and males in the consumption of supplemental or post‐weaning foods. Strontium data suggest a flexible postmarital residence system that favored matrilocality. This may have incentivized greater investment in female offspring.

    

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2. Exploring the effects of weaning age on adult infectious disease mortality among 18th–19th century Italians

   https://doi.org/10.1002/ajhb.23864  

   Smith, April K. ; Reitsema, Laurie J. ; Fornaciari, Antonio ; Sineo, Luca ( January 2023 , American Journal of Human Biology)

   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.

    

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3. Calculus and survivorship in medieval London: The association between dental disease and a demographic measure of general health

   https://doi.org/10.1002/ajpa.23772  

   Yaussy, Samantha L. ; DeWitte, Sharon N. ( January 2019 , American Journal of Physical Anthropology)

   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.

   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.

    

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4. Sex differences in adult famine mortality in medieval London

   https://doi.org/10.1002/ajpa.23930  

   DeWitte, Sharon N. ; Yaussy, Samantha L. ( October 2019 , American Journal of Physical Anthropology)

   Recurrent famine events during the medieval period might have contributed to excess mortality during the Black Death in London, England (c. 1349–1350). Previous research using conventional methods of age estimation revealed that adult males experienced lower risks of mortality under “normal” (attritional) but not famine mortality conditions following the Black Death. However, given the biases inherent in conventional age estimation methods, this study reassesses sex differences in risks of medieval adult famine mortality using ages estimated via transition analysis, which avoids some of the limitations of conventional age estimation methods.

   We apply hazards analysis (the Gompertz model of adult mortality) to ages estimated for human skeletal remains (n= 1245) from London cemeteries dated to the pre‐Black Death (c. 1000–1250 CE) and post‐Black Death (c. 1350–1540 CE) periods.

   The results reveal no sex differences in risks of mortality before the Black Death but indicate that adult males faced lower risks of mortality after the Black Death during conditions of normal and famine mortality.

   These findings largely support those of our previous research, which suggested that selective mortality during the Black Death or sex‐biased improvements in standard of living following the epidemic reduced risk of mortality for adult males in the post‐Black Death period under normal mortality conditions. However, the use of transition analysis age estimates also revealed a reduced risk of mortality for post‐Black Death adult males under famine conditions.

    

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

   https://doi.org/10.1002/ajpa.24279  

   McCool, Weston C. ; Anderson, Amy S. ; Kennett, Douglas J. ( March 2021 , American Journal of Physical Anthropology)

   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.

   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.

    

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