Susan Pfeiffer

The Natural Decomposition of Adipocere

Adipocere is a waxy substance which sometimes forms from the adipose tissue of dead bodies, especially when they are under water. A disinterment in southern Ontario lead to the recovery of extensive adipocere from an interment which occurred in AD 1869. Subsequent laboratory research was designed to explore the conditions under which adipocere will disappear, the goal being to identify strategies for estimating a range of time since death in cases where adipocere is present. Varieties of aerobic or facultatively anaerobic microorganisms from the surface of the adipocere were separated and identified. In culture, the gram positive bacteria were able to degrade the adipocere. We propose that the persistence of adipocere is related to the exclusion of gram positive bacteria from the burial environment. The role of bacteria in adipocere formation and degradation must be understood before we can use the presence of adipocere to extrapolate information about the post-death interval.

Evaluation of Morphological and Histological Adult Skeletal Age-at-Death Estimation Techniques Using Ribs

Adult age-at-death estimation standards were applied to an independent sample (N = 50, 55) of documented ages 17.5 to 95 years. Estimates derived from the sternal rib end morphological and from the cortical rib histological techniques were compared with each other and to the documented ages. Comparisons to the documented ages reveal no statistically significant differences between the techniques. However, the comparison of each individuals estimates show a poor correlation (r = 0.54) despite the equal performance of the age estimations on the entire sample. Averaging of the two rib age estimates results in an estimate with a stronger Pearsons r (0.86) and a lower standard error of the estimate (7.5 years).

Maxillary sinusitis as an indicator of respiratory health in past populations

Chronic infectious respiratory disease in a past human population is investigated through the quantification of maxillary sinusitis among Iroquoian horticulturists. Three hundred forty-eight right and left maxillae of a Southern Ontario Iroquoian skeletal sample, Uxbridge Ossuary, ca. AD 1440, were examined for evidence of chronic infection (minimum number of individuals = 207: 114 adults, 22 adolescents, 38 juveniles and 33 infants). Modern clinical criteria were applied to differentiate lesions of respiratory and dental origin. Osseous lesions of the maxillary sinuses were observed in 50% of the individuals examined. These lesions are morphologically consistent with nonspecific lesions observed in other past populations that have been attributed to the presence of pathogens. The prevalence of maxillary sinusitis increases with age. Osseous changes suggestive of maxillary sinusitis of respiratory origin are at a maximum prevalence in juveniles and adolescents. In adults, infection of dental origin becomes a confounding factor in the identification of sinusitis of respiratory origin. Fifteenth century Iroquoians were experiencing high airborne pathogen levels and poor indoor air quality. The prevalence of maxillary sinusitis and the exploration of the origin of tissue injury may contribute to our reconstruction of the quality of life and the respiratory health status of past human populations.

Low Bone Mass in Past and Present Aboriginal Populations

A slight and gradual loss of bone mass is characteristic of all aging primates, if they live long enough (Garn, 1970; Burr, 1980). Nevertheless, the observation of reduced bone mass among ancestral human skeletal remains is limited to relatively recent populations. Since the domestication of plants roughly 12,000 years ago, skeletal remains from disparate parts of the world have occasionally shown low bone mass. Perhaps earlier populations did not suffer age-related bone loss because they died at young ages (Pfeiffer, 1990), or perhaps their diet or lifestyle facilitated effective bone maintenance. Past human populations were more dependent on local natural resources and their own physical labor for subsistence, a cultural pattern maintained by only a few geographically isolated aboriginal groups today. These “anthropological populations” have been portrayed as natural paradigms whose dietary habits might be studied as representations of our species’ natural “set point” for nutritional requirements, and against which we might evaluate modern regimens and their biological consequences (Eaton et al., 1988; Eaton and Nelson, 1991).

Conditions for Evolution of Small Adult Body Size in Southern Africa

Discoveries from diverse locales indicate that early Homo was sometimes petite. Small body size among fossil forms is difficult to explain because its existence in modern human populations is not fully understood. The history, ethnography, genetics, and bioarchaeology of KhoeSan peoples of southern Africa are reviewed in the context of their small adult body size. Since the Middle Stone Age, at least some southern African foragers were petite. Throughout the Later Stone Age (LSA; the Holocene), most groups followed a mobile, coastally oriented foraging strategy that relied on small package size foodstuffs. Distinctive skeletal shape and allometry of LSA adult skeletons provide clues about selective factors. Neither dietary insufficiency nor heat dissipation models of selection apply in the LSA context. Energetics and avoidance of serious accidents may be relevant factors. An aspect of life history—the timing of cessation of growth—has been assessed by comparing dental and skeletal development within juvenile skeletons. After a slow start, LSA child growth shows a tempo like that of modern children and no evidence of early maturation. Among fossil or recent forms, small body size should be assessed not only as possible evidence of selection for smallness but also as evidence of the absence of selection for large body size.

Bioarchaeological Evidence for the Basis of Small Adult Stature in Southern Africa Growth, Mortality, and Small Stature

Natural selection for small adult body size may be directly linked to various factors that differ by global region. Indirect selection through early cessation of growth has been postulated for pygmy groups. Small adult body size was maintained throughout the Holocene by the ancestors of the KhoeSan groups, Later Stone Age hunter-gatherers who lived in the coastal and near-coastal regions of South Africa. Contextual information from 134 burials of juveniles (76 with radiocarbon dates) is combined with assessment of child growth. Both timing of cessation of growth and patterns of juvenile mortality are pertinent to questions about the possible selective value of smallness. Later Stone Age juveniles who had dental ages in the midteen years had not yet achieved adult size; hence, early cessation of growth is not evident. For the period between ca. 3800 and 1800 BP, which was a time of increased variability in adult body size, there are more burials of older juveniles. The variability in the mortality profile suggests fluctuations in the rates of juvenile mortality rather than consistently high rates. We conclude that small body size had been established by the Holocene, and we suggest that its maintenance is linked to direct rather than indirect selection.

Determination of Sex from Adult Human Ribs

ABSTRACTWhen identifying unknown human remains, categorization by sex is critical. Highly dimorphic elements such as the pelvis and skull are often missing or damaged. This study investigates the existence of sexual dimorphism at gross and histological levels in human ribs. The sample consists of one mid-thoracic rib from each of 58 adults (31 females, 27 males, ages 25 to 50) from the skeletons excavated from the crypt (1729–1852 AO) of Christ Church in Spitalfields, East London, Great Britain. Funerary records of sex and age at death allow for exceptional control of these variables. Measurements include minimum and maximum rib diameter, total area and cortical area, as well as the histological variables of total osteon area and total haversian area. The gross measures of the rib reveal high degrees of sexual dimorphism (female: male, 75:100), while the histological measures show no statistically significant differences between the sexes. On the basis of gross morphological variables alone, males and fem...

Bone-Remodelling Age Estimates Compared With Estimates by Other Techniques

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Allometry of head and body size in holocene foragers of the south african cape

Opportunities to assess morphological allometry in small-bodied human populations are rare. The foragers of the Later Stone Age of the South African Cape are characteristically small-bodied. Previous studies have shown that during the period of ca. 3500 to 2000 years BP (uncalibrated (14) C dates), the regional population shows transient reduced stature, body mass, and cranial size, a pattern that has been tentatively tied to demographic pressure on resources. This study examines the relationships among cranial size (centroid size) and body size (femoral length, femoral head diameter, and bi-iliac breadth) during the second half of the Holocene (N = 62). Reduced major axis regression indicates negative allometry of cranial centroid size with body size. Residuals (from ordinary least squares regression of cranial centroid size on body size) are regressed on radiocarbon date to examine temporal changes in the relationship between cranial and body size. Cranial and pelvic sizes are most conserved through time, while more ancient skeletons possess shorter femora and smaller femoral heads. The relationship between cranial centroid size and femoral length shows larger and more variable residuals at more recent dates, indicating a greater or more variable disassociation between cranial size and stature relative to more ancient skeletons. A similar, but nonsignificant relationship exists between cranial size and bi-iliac breadth. These results provide insights into the use of aspects of body size and proportionality in the assessment of health in past populations.

Juvenile mortality in Southern African archaeological contexts

Estimates of age at death that are both accurate and precise can provide information about the patterns and causes of premature mortality in both Later Stone Age and Iron Age archaeology. Assuming a link between subsistence and health, differences in patterns of childhood growth are hypothesized. The best source of this information comes from the formation of tooth crowns and roots. Through the study of femur shafts from Later StoneAge juvenile skeletons, it can be demon strated that linear growth was normal in tempo. The study offemora from a smaller number of Iron Age juvenile skeletons suggests that growth in this group did notfollow a normal pattern, perhaps because prolonged ill health preceded death. Growth of Iron Age children who failed to reach adulthood appears to be variable but slow and this may provide insights into the Iron Age biosocial environment. Because of the demonstrated correlation between dental development and femur shaft length, the Later Stone Age juvenile long bone lengths provided here can be used in Later Stone Age contexts to estimate chronological age at death if dental information is unavailable. This approach should not be used in Iron Age contexts, since such an approach is likely to yield biased (under-aged) estimates of age at death.