Age and sex bias in the reconstruction of past population structures

Palaeodemographical studies are founded on the assumption that the sex and age distribution of the skeletal sample reflects the constitution of the original population. It is becoming increasingly clear, however, that the type and amount of information that may be derived from osteoarchaeological collections are related to the state of preservation of remains. This work proposes a new method to evaluate bone preservation, to identify age and sex biases in the preservation of human skeletal remains, and to assess whether differences in preservation patterns are more dependent on factors intrinsic or extrinsic to anatomical features of human bones. Three osteological collections and over 600 skeletons were observed. The state of preservation of human bones was assessed using three preservation indexes: the anatomical preservation index (API), the bone representation index (BRI), and the qualitative bone index (QBI). The results suggest that subadult skeletons are generally more poorly preserved and with bones less well-represented than adult skeletons. Among subadults, female and male skeletons have different patterns of preservation according to their age. This pattern of preservation depends on intrinsic anatomical properties of bones themselves, while external factors can only increase these differences in the state of preservation and representation of osseous remains. It is concluded from this that failure to recognize these differences may lead to misleading interpretations of paleodemography of past human populations.     

年龄鉴定的转换分析法及其在月家庄墓地人骨中的应用

转换分析是一种基于贝叶斯统计的人骨年龄鉴定新方法,具有综合多种年龄标志物、不受参考样本影响、适用于老年个体等优势。本文将其用于陕西洛川月家庄墓地人骨年龄鉴定并与传统方法进行对比。结果表明,两种方法构建出的人群死亡年龄结构、生存过程有显著差异：转换分析得到的最高寿命、平均死亡年龄明显高于传统方法,更多个体可存活至中老年。两种方法鉴定出的年龄差值受样本保存状况、年龄阶段的影响,存在结构性差别。转换分析是人骨年龄鉴定方法的重大创新,使鉴定过程标准化、鉴定误差定量化。未来需使用一些年龄已知的个体开展更多验证研究,以评估该方法对我国人骨样本的适用性及不同软件间的差异。     

Life expectancy of the 20th century Venda: A compilation of skeletal and cemetery data

Little information is available on the 20th century mortality rates of rural black South African groups, such as the Venda. The purpose of this study was to apply abridged life tables in order to estimate life expectancy from both skeletal remains and death registry information of modern South African communities. Comparisons were also made with prehistoric and contemporary groups as a means to better evaluate life expectancy for this time period. The sample consisted of 160 skeletons of known Venda origin and burial registry information for 1364 black South Africans from the Rebecca Street and Mamelodi Cemeteries in Pretoria, South Africa. Standard anthropological techniques were applied to determine sex and estimate age from the skeletal remains. The stationary and non-stationary life table models were used to analyse the data. A high rate of child mortality, low juvenile and adult mortality with a steady increase in mortality after the age of 30 years was observed for both the Venda and the cemetery samples. Throughout the 20th century, life expectancy was shown to increase for black South Africans. However, due to the widespread HIV infection/AIDS of the 21st century, infant and young adult mortality rates continue to rise at such a speed that the decline in mortality seen for South Africans in the last 50 years will most likely to be lost in the next decade due to this disease.     

Survived spondyloptosis of the thoracic spine in the Early Middle Ages (Czech Republic)

At a Slavic site Pohansko near B?eclav (Czech Republic), at the burial ground around the church (9th–10th century) 757 skeletons (208 males, 159 females, 354 sub-adults and 36 undetermined individuals), were excavated. More or less complete vertebral column was preserved in 109 adults. Among those, in the grave number 403, the skeletal remains of an adult male were found with the deformity of the spine probably caused by severe trauma (spondyloptosis). Due to the poor preservation of the caudal part of the spine, we cannot exclude diagnoses including spondylitis tuberculosa and developmental defects of the spine such as the persistence of neurocentral synchondroses, or the retrosomatic cleft. Considering the first possible diagnosis to be the most probable, it would be the first survived case of spondyloptosis identified in the palaeopathological literature.     

The Black Death in Hereford,England: A demographic analysis of the Cathedral 14th-century plague mass graves and associated parish cemetery

Objectives

This study explores the paleoepidemiology of the Black Death (1348–52 AD) mass graves from Hereford, England, via osteological analysis. Hereford plague mortality is evaluated in the local context of the medieval city and examined alongside other Black Death burials.

Methods

The Hereford Cathedral site includes mass graves relating to the Black Death and a 12th-16th century parish cemetery. In total, 177 adult skeletons were analyzed macroscopically: 73 from the mass graves and 104 from the parish cemetery. Skeletal age-at-death was assessed using transition analysis, and sex and stress markers were analyzed.

Results

The age-at-death distributions for the mass graves and parish cemetery were significantly different (p = 0.0496). Within the mass graves, young adults (15–24 years) were substantially over-represented, and mortality peaked at 25–34 years. From 35 years of age onwards, there was little variation in the mortality profiles for the mass graves and parish cemetery. Males and females had similar representation across burial types. Linear enamel hypoplasia was more prevalent within the mass graves (p = 0.0340) whereas cribra orbitalia and tibial periostitis were underrepresented.

Conclusions

Mortality within the Hereford mass graves peaked at a slightly older age than is seen within plague burials from London, but the overall profiles are similar. This demonstrates that young adults were disproportionately at risk of dying from plague compared with other age groups. Our findings regarding stress markers may indicate that enamel hypoplasia is more strongly associated with vulnerability to plague than cribra orbitalia or tibial periostitis.     

Differential skeletal preservation at Windover Pond: causes and consequences

In this paper, we evaluate the causes of differential skeletal preservation in the Windover Pond skeletal series (8BR246). We collected data on sex and age for approximately 110 individuals, and calculated a preservation score for each individual based on the presence of 80 skeletal landmarks. Our research questions evaluated the relationship between bone preservation and individual age and sex, and between the presence of preserved brain material and skeletal preservation, and the effects of burial location on bone preservation. The results indicate variability in average preservation for the sample (micro = 0.53, SD = 0.22) with an apparent lack of sex-specific (P = 0.79) or age-specific (P = 0.37) differences in preservation. The relationship between brain and skeletal preservation (P = 0.15) was not significant. The horizontal distribution of burials was not significantly correlated with skeletal preservation (north: r = -0.10, P = 0.93; east: r = 0.09, P = 0.45); however, vertical depth was a significant predictor of preservation (r = -0.31, P = 0.005), indicating that skeletal preservation decreased as burials were located closer to the ground surface. The observed variability in preservation scores may be related to the partial drying and resubmergence of the uppermost burials for the last few millennia. Comparison of Windover element-specific survival rates with previous analyses based on terrestrial samples (Galloway et al. [1997] Forensic taphonomy, Boca Raton: CRC Press; Waldron [1987] Death, decay and reconstruction, Manchester: Manchester University Press; Willey et al. [1997] Am J Phys Anthropol 104:513-528) affirms the relationship between element weight or density and bone survival. The unique taphonomic context of our study sample effected little change in bone deterioration processes.     

Odontometric determination of sex at Mound 72, Cahokia

The mortuary context of Mound 72 at the Cahokia site is one of the most unusual ever described in prehistoric North America. Previous skeletal analyses suggested that four large mass graves within the mound contained only female skeletons. However, these findings were complicated by extremely poor bone preservation that limited the number of skeletal observations that could be made. Furthermore, most skeletons were aged in the 15–25 year range, a time when sexually dimorphic bony traits may still be developing. In this study, dental remains were used to examine sex in the four presumably all‐female mass graves in Mound 72. Additional sources of information, including the original field/laboratory notes and new sexing data based on modern standards, were gathered to fully evaluate the dental estimates. Initially, discriminant function analysis was performed on odontometrics using the original Mound 72 sex assignment. Inconsistent results indicated that some of the skeletons may have been misclassified in the original analyses. To overcome this issue, discriminant function equations were generated using a large pooled skeletal sample from two sites in close temporal and geographic proximity to Cahokia. Application of the equations to Mound 72 revealed that each of the four mass burial groups contained individuals classified as male. These assignments were checked against the skeletal remains and the original field/laboratory notes. Discussion centers on how the results affect previous archaeological interpretations as well as the methodological considerations associated with this study. Am J Phys Anthropol 151:408–419, 2013.© 2013 Wiley Periodicals, Inc.     

The ‘Prof. Dr. Rómulo Lambre’ Collection: An Argentinian sample of modern skeletons

This paper describes the ‘Prof. Dr. Rómulo Lambre’ skeletal collection. The Lambre Collection is housed in the School of Medical Sciences of the National University of La Plata and it consists of skeletal remains ceded by the Municipal Cemetery of La Plata. The collection has more than four hundred skeletons, with information on age, sex, nationality, date and cause of death. It was created for teaching and research purposes in compliance with current legislation, and its management meets guidelines specified in the Declaration of the Argentinian Association for Biological Anthropology on Research Ethics on Human Remains (2007).     

The MAD legacy: How meaningful is mean age-at-death in skeletal samples

This study examines the representativeness of palaeodemographic reconstructions from human skeletal remains. Mean age-at-death (MAD) is the primary statistic used in interpretations of changing patterns of health and well being from palaeodemographic analyses. A series of sampling experiments were conducted on three documented 19th century samples representing the total cemetery population from which skeletal samples could be drawn. Comparisons of the age-at-death distributions of simulated skeletal samples to the parent population were made to assess the relative magnitude of deviation associated with different types of bias (age, sex, temporal). From the examples presented, variability in age-at-death distribution is high in samples of less than 100, suggesting that for samples of less than 100analyzable individuals, it is probable that the mortality profiles constructed are not an accurate reflection of the cemetery. It is proposed that whateverprocess mean age-at-death reflects for past populations (fertility or mortality), is irrelevant if the sample on which the statistic is calculated is not representative of the population. Given that most cemetery samples will be subject, differentially, to biases at a variety of levels, comparative studies based on palaeodemographic data cannot be considered reliablewithout careful control for those biases. It is suggested that representativeness is the primary theoretical obstacle for researches to overcome, and that it is necessary to shift our focus to rigorously exploring those factors that bias our samples. Without some direct quantification of the representativeness of a sample, palaeodemographic estimators such as mean age-at-death are meaningless and any subsequent interpretations regarding the past, dubious at best.     

Iberomaurusian funerary behaviour: evidence from Grotte des Pigeons, Taforalt, Morocco

Grotte des Pigeons at Taforalt, north-east Morocco, is well known for a large assemblage of Iberomaurusian (Epipalaeolithic) skeletons, possibly representing the earliest and most extensively used prehistoric cemetery in North Africa. New archaeological excavations carried out in 2005 and 2006 revealed further human remains in a largely undisturbed burial area in an alcove at the back of the cave. This discovery provides the first opportunity to report on Iberomaurusian human mortuary activity at this site. Reported here are a closely spaced and inter-cutting series of four burials. These contained the remains of four adults, of which three were buried in a seated or slightly reclining position facing towards the cave entrance and one was buried in a highly flexed position on its left side. The distribution of articulated and disarticulated bones suggested intensive use of the area, with earlier burials disturbed or truncated by subsequent burials, and displaced skeletal elements deliberately or unwittingly incorporated into later depositions. Through this process, parts of a single skeleton were redistributed among several discrete graves and within the surrounding deposit. Some aspects of the Iberomaurusian funerary tradition that are evident from the human remains excavated in the 1950s are absent in the newly excavated adult burials, suggesting a possible elaboration of funerary activity over time.     

Paleodemography of the Carlston Annis (Bt-5) Late Archaic skeletal population

The study presents a demographic assessment of the Carlston Annis (Bt-5) Late Archaic hunting and gathering population recovered from the banks of the Green River in west-central Kentucky. The shell midden habitation and cemetery site originally yielded the remains of 390 individuals. Radiocarbon dates place site occupation between 3,000 and 4,500 y.b.p. The skeletal sample consisted of 354 individuals ranging in age from 7 months in utero to 70 + years. Subadults were aged by seriation of dental and skeletal developmental criteria. Adult ages were determined by the multifactorial summary age method that employed 1) five indicators of adult skeletal age at death, 2) the procedure of age indicator seriation, and 3) differential weighting of age assessments as determined by principal components analysis. Adult sex diagnoses were based on qualitative assessment of pelvic and cranial morphological criteria. The Bt-5 life table analysis yields an E0 of 22.4 years, crude birth of 45, mean family size of 3.3, gross reproductive rate of 2.7, generation length of 26.6 years, and B of .076, indicating a healthy population with a substantial capability to replace succeeding generations. Survivorship profiles and demographic parameters that compare the Carlston Annis (Bt-5) and Indian Knoll (Oh-2) skeletal series are presented. Both populations display type II survivorship curves, with high infant mortality and early onset of elevated mortality rates in adults. Major differences between Bt-5 and Oh-2 demographic parameters concern adult sex ratio and adult age distribution over 30 years. These differences are interpreted to reflect census errors in the Oh-2 demographic reconstruction that were possibly introduced by selective methodological biases and/or taphonomic factors.     

A new method for assessing the sex of fragmentary skeletal remains: femoral shaft circumference

A simple discriminant function using midshaft femoral circumference for the determination of sex has been tested with 114 skeletons from the Libben Site, Ontario County, Ohio. The results have been shown to be 85% consistent with other, accepted means of determining sex. Femur circumference an be an aid to the sexual identification of poorly preserved and fragmentary skeletal remains.     

Basics in paleodemography: a comparison of age indicators applied to the early medieval skeletal sample of Lauchheim

Recent advances in the methods of skeletal age estimation have rekindled interest in their applicability to paleodemography. The current study contributes to the discussion by applying several long established as well as recently developed or refined aging methods to a subsample of 121 adult skeletons from the early medieval cemetery of Lauchheim. The skeletal remains were analyzed by 13 independent observers using a variety of aging techniques (complex method and other multimethod approaches, Transition Analysis, cranial suture closure, auricular surface method, osteon density method, tooth root translucency measurement, and tooth cementum annulation counting). The age ranges and mean age estimations were compared and results indicate that all methods showed smaller age ranges for the younger individuals, but broader age ranges for the older age groups.     

Isotopic evidence of dietary variations and weaning practices in the Gaya cemetery at Yeanri,Gimhae, South Korea

Stable carbon and nitrogen isotope analyses were conducted to investigate dietary variation in human skeletons (n = 109) from the Gaya cemetery at Yeanri located near Gimhae City, South Korea. The cemetery contained three distinct grave types dating to 4th–7th century AD. The main purposes of this research were to reconstruct palaeodiet in the Gaya population and to explore correlations between stable isotope compositions and burial types, inferred age, and sex of these individuals. The isotopic data indicate that the people at Yeanri consumed a predominantly C₃‐based terrestrial diet supplemented with freshwater and/or marine resources. The comparison of isotopic results reveals significant differences in δ¹³C values among three adult burial types (wood‐cist coffin: ?18.5 ± 0.5‰, stone‐cist coffin: ?18.1 ± 0.6‰, mausoleum: ?17.8 ± 0.9‰). Males in wood‐cist and stone‐cist coffins have relatively more elevated mean δ¹³C and δ¹⁵N values than females. The isotopic ratios from the two adult age groups (21–40 years and 40–60 years) indicate that there was no significant dietary change in individuals with age. The isotope data from the infants and children suggest the weaning was a gradual process that was completed between 3 and 4 years of age in the Gaya population. This evidence indicates that the dietary variations within the cemetery reflect social status, sex, and childhood consumption patterns. Am J Phys Anthropol, 2010. © 2009 Wiley‐Liss, Inc.     

Middle Palaeolithic burial is not a dead issue: the view from Qafzeh, Saint-Césaire, Kebara, Amud, and Dederiyeh.

Inferences of purposeful Middle Palaeolithic (MP) burial are almost universally accepted, despite published arguments that the pre-1960s discoveries are equally well explained by natural processes. In the modern human origins debate (perhaps the most hotly disputed question in palaeoanthropology) inferences of MP burial are crucial in arguments for an early Upper Pleistocene emergence of modern humans. The present paper contributed to that debate by re-examining a number of post-1960s excavations of MP hominid remains. Because these were excavated with meticulous attention to depositional circumstances and stratigraphic context, most palaeoanthropologists consider these inferences of purposeful burial to be based on irrefutable evidence. This paper focuses on the reasoning behind such claims, especially the assumption that articulated sketetal material is prima facie evidence for deliberate burial. First it reviews a range of processes operating in caves and rockshelters that condition the probability of articulated skeletal material preserving without hominid intervention. Processes such as deposition, decomposition, and disturbance are inherently more variable in caves and rockshelters than is usually acknowledged. The first section concludes that purposeful protection is not necessary to account for the preservation of articulated skeletal remains. The second part of the paper examines the published record from Qafzeh, Saint-Césaire, Kebara, Amud and Dederiyeh, where the majority of the remains claimed to have been buried are fragmented, incomplete, and disarticulated. This re-examination suggests that in all of the post-1960s cases of putative burial, the hominid remains occur in special depositional circumstances, which by themselves are sufficient to account for the preservation in evidence at these sites. This conclusion severely weakens arguments for purposeful burial at the five sites. Moreover, the equivocal nature of the evidence in the more recent cases renders even less secure the similar claims made for discoveries of hominid skeletal remains at La Chapelle-aux-Saints, Le Mousterier, La Ferrassie, Teshik-Tash, La Grotte du Régourdou, Shanidar, and several others. Finally, by highlighting the equivocal nature of the evidence, this paper underscores the ongoing need for palaeoanthropologists to specify as wide a range of taphonomic processes as possible when interpreting the archaeological record. This will aid in producing robust inferences, and will bring about increasingly accurate knowledge of when hominids became human.     

A new reference collection of documented human skeletons from Mérida,Yucatan, Mexico

This report documents the history and composition of a new reference collection currently composed of 84 identified human skeletons from the modern cemetery of Xoclán in Mérida, Yucatan, Mexico. The skeletal sample is the first of its kind in the Yucatan peninsula, a region with a population short of two million mostly local and non-local Mexican residents and descendants of the ancient Maya. The growing collection is curated at the Facultad de Ciencias Antropológicas (School of Anthropological Sciences) of the Autonomous University of Yucatan. Here we describe recovery procedures, preservation, background information and validation measures of the individuals who make up the collection. Detailed information on the generational pattern, sex, and age distribution, along with socioeconomic context and provenience of the skeletons are provided. The majority of the skeletal series is represented by males and by older individuals of both sexes. Almost all of these individuals come from Mérida's middle and lower socioeconomic sectors and died within the urban city boundaries. Biographic information was collected on each individual at the municipal civil registry and confronted with information of national and municipal censuses (2000 and 2005), to be validated and to be discussed here in terms of the representativeness of the reference series and its potential uses in forensic, anthropological and medical research.     

Histologic examination of age of the First African Baptist Church adults

This study applies a recently formulated method of histologic estimation of age at death to samples of anterior femoral cortex taken from adult skeletons from the First African Baptist Church cemetery and compares the results with macroscopic age estimates made by J.L. Angel and J.O. Kelley. Of the 65 samples taken, 44 were sufficiently well preserved to produce readable thin sections, although most were so fragile that they had to be embedded before sectioning. In most cases the histologic ages agreed with the macroscopic age estimations within the standard error of the estimate of the histologic method. Most cases of disagreement could be attributed to poor preservation. Despite differences between individual gross and microscopic age estimates, the two methods proved to be significantly correlated and produced the same overall demographic picture of a population whose female members were likely to die at earlier ages than the males.     

Fractures in late medieval skeletal populations from Serbia

Bone fractures were analyzed from skeletal remains of 861 adult individuals from six cemeteries dating to the Late Medieval period in Serbia. Results of the study were compared to other cemetery populations (635 individual skeletons) of the same date and region in an attempt to understand fracture patterns. The association of types of fractures and their prevalence with sex, age at death, cemetery site, and information deriving from historical sources are discussed. Results showed that the long bone fracture frequency was 0.7%, and the majority of the fractures were the result of direct force. This rate is similar to some studies of contemporary British skeletal samples. However, it is much lower than for some other Old World sites. Cranial vault fractures had a rate of 6.7%, and of the facial skeleton, 1.3%; the frontal bone was the most affected of bones of the cranial vault. Injuries were more common on the upper extremities (0.8%) compared to the lower (0.6%). However, the fibula was the most fractured bone (2.8%), followed by the ulna (2.4%). This pattern is similar to three of six Late Medieval urban sites in Britain. These findings suggest that this rural community was exposed to a low risk of trauma, probably related mostly to accidents sustained during farming, and rarely to interpersonal violence.     

Loss of identity in nineteenth-century Norway: Oslo's House of Correction

In Norway, there was considerable overlap between the poor house, the workhouse, and correctional facilities. An assemblage of human skeletal remains from Oslo's House of Correction cemetery, largely comprised of individuals disturbed during municipal development in 1989, consists of c. 314 individuals who died as inmates or residents; many were disabled or elderly. Although names were recorded at death, the cemetery lacked grave markers or a map, with no expectation families might one day reclaim relatives. All remains have been aged and sexed anthropologically, with samples collected for biomolecular investigations. Despite extensive archival documentation, including names recorded in the House of Correction church book, their identities are shrouded by time. Observations of age, injury, and disease can suggest why inmates ended up in the House of Correction cemetery. But there, individual stories end and identities are lost.     

Social implications of mortality patterns of juveniles from Poundbury Camp, Romano-British Cemetery

Attempts have been made to reconstruct the Romano-British population that was buried at Poundbury Camp, Dorchester, England. Over 1400 graves were excavated and about 1200 skeletons of adults and juveniles were recovered, dating from the 1st to the 5th Centuries AD. The burial patterns indicate that the family was the important unit in the community that was served by Poundbury Camp. The newborn but perhaps not the stillborn were buried in the cemetery. Infanticide was not practised. Infant mortality was high and weaning may have been at a very early age. There were relatively few children and family sizes must have been small. Among the adolescents there were three times as many girls as boys. This is interpreted as a consequence of the materialism of a society with an agrarian economy.