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。     

Estimation of adult skeletal age‐at‐death using the Sugeno fuzzy integral

Age‐at‐death estimation of an individual skeleton is important to forensic and biological anthropologists for identification and demographic analysis, but it has been shown that the current aging methods are often unreliable because of skeletal variation and taphonomic factors. Multifactorial methods have been shown to produce better results when determining age‐at‐death than single indicator methods. However, multifactorial methods are difficult to apply to single or poorly preserved skeletons, and they rarely provide the investigator with information about the reliability of the estimate. The goal of this research is to examine the validity of the Sugeno fuzzy integral as a multifactorial method for modeling age‐at‐death of an individual skeleton. This approach is novel because it produces an informed decision of age‐at‐death utilizing multiple age indicators while also taking into consideration the accuracies of the methods and the condition of the bone being examined. Additionally, the Sugeno fuzzy integral does not require the use of a population and it qualitatively produces easily interpreted graphical results. Examples are presented applying three commonly used aging methods on a known‐age skeletal sample from the Terry Anatomical Collection. This method produces results that are more accurate and with smaller intervals than single indicator methods. Am J Phys Anthropol 2010. © 2009 Wiley‐Liss, Inc.     

The influence of body size on adult skeletal age estimation methods

Accurate age estimations are essential to archaeological and forensic analyses. However, reliability for adult skeletal age estimations is poor, especially for individuals over the age of 40 years. This is the first study to show that body size influences skeletal age estimation. The ??can et al., Lovejoy et al., Buckberry and Chamberlain, and Suchey‐Brooks age methods were tested on 764 adult skeletons from the Hamann‐Todd and William Bass Collections. Statures ranged from 1.30 to 1.93 m and body masses ranged from 24.0 to 99.8 kg. Transition analysis was used to evaluate the differences in the age estimations. For all four methods, the smallest individuals have the lowest ages at transition and the largest individuals have the highest ages at transition. Short and light individuals are consistently underaged, while tall and heavy individuals are consistently overaged. When femoral length and femoral head diameter are compared with the log‐age model, results show the same trend as the known stature and body mass measurements. The skeletal remains of underweight individuals have fewer age markers while those of obese individuals have increased surface degeneration and osteophytic lipping. Tissue type and mechanical loading have been shown to affect bone turnover rates, and may explain the differing patterns of skeletal aging. From an archaeological perspective, the underaging of light, short individuals suggests the need to revisit the current research consensus on the young mortality rates of past populations. From a forensic perspective, understanding the influence of body size will impact efforts to identify victims of mass disasters, genocides, and homicides. Am J Phys Anthropol 156:35–57, 2015 © 2014 Wiley Periodicals, Inc.     

An elusive paleodemography? A comparison of two methods for estimating the adult age distribution of deaths at late Classic Copan,Honduras

Comparison of different adult age estimation methods on the same skeletal sample with unknown ages could forward paleodemographic inference, while researchers sort out various controversies. The original aging method for the auricular surface (Lovejoy et al., 1985a) assigned an age estimation based on several separate characteristics. Researchers have found this original method hard to apply. It is usually forgotten that before assigning an age, there was a seriation, an ordering of all available individuals from youngest to oldest. Thus, age estimation reflected the place of an individual within its sample. A recent article (Buckberry and Chamberlain, 2002) proposed a revised method that scores theses various characteristics into age stages, which can then be used with a Bayesian method to estimate an adult age distribution for the sample. Both methods were applied to the adult auricular surfaces of a Pre-Columbian Maya skeletal population from Copan, Honduras and resulted in age distributions with significant numbers of older adults. However, contrary to the usual paleodemographic distribution, one Bayesian estimation based on uniform prior probabilities yielded a population with 57% of the ages at death over 65, while another based on a high mortality life table still had 12% of the individuals aged over 75 years. The seriation method yielded an age distribution more similar to that known from preindustrial historical situations, without excessive longevity of adults. Paleodemography must still wrestle with its elusive goal of accurate adult age estimation from skeletons, a necessary base for demographic study of past populations.     

Cementum annulations,age estimation,and demographic dynamics in Mid-Holocene foragers of North India

One of the principal problems facing palaeodemography is age estimation in adult skeletons and the centrist tendency that affects many age estimation methods by artificially increasing the proportion of individuals in the 30–45-year age category. Several recent publications have indicated that cementum annulations are significantly correlated with known age of extraction or death. This study addresses the question of how demographic dynamics are altered for an archaeological sample when cementum-based age estimates are used as opposed to those obtained via conventional macroscopic methods. Age pyramids were constructed and demographic profiles were compared for the early Holocene skeletal population from Damdama (India). The results demonstrate that the use of cementum annulations for age estimation in only a subset of the skeletal sample has a significant impact on the demographic profile with regard to specific parameters such as mean age at death and life expectancy at birth. This confirms the importance of using cementum annulations to refine age estimates in archaeological samples, which, when combined with a fertility-centred approach to demography, can provide new insights into population dynamics in the past.     

Brief communication: Estimates of some demographic parameters in a neolithic rock-cut chamber (approximately 2000 BC) using iterative techniques for aging and demographic estimators

Two new techniques—one anthropological, which estimates the mean age at death for adult skeletons, the other demographic, which gives main survivorship curve parameters—are used on a sample of skeletons (N ≅ 170) discovered in a Neolithic rock-cut chamber (Loisy-en-Brie, France). The iterative technique for aging used a stochastic sampled F matrix derived from the trabecular involution of the femoral head observed in the reference collection of Coimbra (Portugal; N = 421). The results, obtained from techniques and data, independent of each other, are strongly consistent. Overall, they give a life expectancy at birth of about 25–28 years and the probability of death at 1 and 5 years, respectively, of about .271-.249 and .429-.380. Am J Phys Anthropol 102:569–575, 1997. © 1997 Wiley-Liss, Inc.     

Anatomical, physiological, and epidemiological correlates of the aging process: a confirmation of multifactorial age determination in the Libben skeletal population

Paleodemographic analyses based on estimates of skeletal age at death consistently report high levels of young adult mortality with few individuals living in excess of 50 years. Critics assert these data indicate systematic underaging of adults and justifiably remark that criteria for estimating skeletal age at death may be unreliable, age determinations are too frequently based on one or two criteria alone, and adult paleodemographic age profiles often mimic the age distribution of the modern population from which an age indicator's standards were originally derived. This study reports a series of tests based on well-documented biological aging phenomena that can be used to investigate potential effects of systematic underaging in adults, assuming the skeletal population is of sufficient size to permit such tests. These include patterns of third decade sternal clavicular epiphyseal fusion, multiple age and sex criteria associated with cortical bone dynamics, and fractures known to occur throughout the entire adult ages range. These phenomena are examined here for the Libben site skeletal population where adult age at death was determined by the multifactorial summary age technique. None of the biological criteria reported here were used in the Libben summary age analysis and thus serve as an independent test of accuracy in age determination. In addition, the summary age method has recently been applied to a series of modern skeletons of known age (Todd samples 1 and 2). Age standards for criteria employed with Libben and Todd 1 were identical. Since Todd 1 displayed underaging in older adults, a second Libben age distribution adjusted for Todd 1 bias was generated for comparison. A third Libben adult survivorship profile based on a Coale and Demeny West level 3 mortality experience, considered by some to be a more realistic model for skeletal populations, was produced for comparison. For all criteria examined, original Libben summary ages provided superior concordance with known patterns of biological aging in human populations. While Libben ages adjusted for Todd 1 bias were slightly better in the third decade, both Todd 1 adjusted and Coale and Demeny West level 3 age distributions produced unrealistic patterns of biological aging for individuals greater than 35 years. Implications of these results are discussed.     

Brief communication: infracranial maturation in the skeletal collection from Coimbra, Portugal: new aging standards for epiphyseal union

Age at death of a single skeletal individual or a group is essential information in archaeological, paleoanthropological, and forensic contexts. Dental remains are the most commonly used age indicators, but when the dentition is not available, or too few teeth are present for an accurate age assessment, other age indicators such as skeletal maturation must be used. Of particular utility in this regard is the fusion of the epiphyses of the infracranial skeleton. Here we present new aging standards based on the infracranial maturation of individuals from the known age and sex collection from Coimbra, Portugal. We scored infracranial epiphyseal fusion and spheno-occipital synchondrosis closure (64 loci of ossification in total) on 137 skeletons from individuals between 7 and 29 years old. We further discuss developmental differences between the sexes and similarities and differences between the Coimbra documented collection and other published aging standards.     

Brief communication: the collection of identified human skeletons housed at the Bocage Museum (National Museum of Natural History), Lisbon, Portugal

A large collection of identified human skeletons curated at the Bocage Museum (National Museum of Natural History, Lisbon, Portugal) has remained in relative anonymity since its collecting protocol was initiated in the 1980s. This collection originates from modern cemetery sources and is comprised of 1,692 skeletons with basic documentary data (age at death, place of birth, occupation, place of residence, and date and cause of death). At present, this information is more readily available for 699 individuals. The remaining 993 are in the process of being fully documented. The skeletons consist largely of Portuguese nationals who lived in the 19th and 20th centuries (1805-1975) in Lisbon. Both sexes are equally represented, and ages at death range from birth to 98 years, including 92 subadults (<20 years old).     

The history and composition of the Raymond A. Dart Collection of Human Skeletons at the University of the Witwatersrand,Johannesburg, South Africa

The Raymond A. Dart Collection of Human Skeletons (Dart Collection) is housed in the School of Anatomical Sciences at the University of the Witwatersrand, Johannesburg, South Africa, and comprises one of the largest documented cadaver‐derived human skeletal assemblages in the world. This collection originated in the early 1920s as a result of the efforts of Raymond Dart and continues to grow. The skeletons included represent varied indigenous and immigrant populations from southern Africa, Europe and Asia. This contribution documents the history of the collection and provides an updated inventory and demographic assessment of this valuable research collection. According to a recent inventory the Dart Collection currently comprises 2,605 skeletons representing individuals from regional SA African (76%), White (15%), Coloured (4%) and Indian (0.3%) populations. A large proportion of the skeletons (71%) represent males. The recorded ages at death range from the first year to over 100 years of age, but the majority of individuals died between the ages of 20 and 70. The Dart Collection has been affected by collection procedures based on availability. All of the cadavers collected before 1958, and large proportions subsequently, were derived from unclaimed bodies in regional South African hospitals. Some details of documentation (age at death, population group) are estimates and some aspects of the collection demographics (sex ratios) do not closely reflect any living South African population. Our inventory and analysis of the Dart Collection is aimed to assist researchers planning research on the materials from this collection. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.     

Application of the anatomical method to estimate the maximum adult stature and the age‐at‐death stature

This study focuses on the age adjustment of statures estimated with the anatomical method. The research material includes 127 individuals from the Terry Collection. The cadaveric stature (CSTA)–skeletal height (SKH) ratios indicate that stature loss with age commences before SKH reduction. Testing three equations to estimate CSTA at the age at death and CSTA corrected to maximum stature from SKH indicates that the age correction of stature should reflect the pattern of age‐related stature loss to minimize estimation error. An equation that includes a continuous and linear age correction through the entire adult age range [Eq. (1)] results in curvilinear stature estimation error. This curvilinear stature estimation error can be largely avoided by applying a second linear equation [Eq. (2)] to only individuals older than 40 years. Our third equation [Eq. (3)], based on younger individuals who have not lost stature, can be used to estimate maximum stature. This equation can also be applied to individuals of unknown or highly uncertain age, because it provides reasonably accurate estimates until about 60/70 years at least for males. Am J Phys Anthropol 152:96–106, 2013. © 2013 Wiley Periodicals, Inc.     

Detection of significant demographic differences between subpopulations of prehispanic Maya from Copan, Honduras, by survival analysis

Heterogeneity and small sample size are problems that affect many paleodemographic studies. The former can cause the overall distribution of age at death to be an amalgam that does not accurately reflect the distributions of any of the groups composing the heterogeneous population. The latter can make it difficult to separate significant from nonsignificant demographic differences between groups. Survival analysis, a methodology that involves the survival distribution function and various regression models, can be applied to distributions of age at death in order to reveal statistically significant demographic differences and to control for heterogeneity. Survival analysis was used on demographic data from a heterogeneous sample of skeletons of low status Maya who lived in and around Copan, Honduras, between A.D. 400 and 1200. Results contribute to understanding the collapse of Classic Maya civilization.     

Contrasting Demographic Structure of Short‐ and Long‐lived Pioneer Tree Species on Amazonian Forest Edges

Although tropical forests have been rapidly converted into human‐modified landscapes, tree species response to forest edges remains poorly examined. In this study, we addressed four pioneer tree species to document demographic shifts experienced by this key ecological group and make inferences about pioneer response to forest edges. All individuals with dbh ≥ 1 cm of two short‐lived (Bellucia grossularioides and Cecropia sciadophylla) and two long‐lived species (Goupia glabra and Laetia procera) were sampled in 20 1‐ha forest edge plots and 20 1‐ha forest interior plots in Oiapoque and Manaus, Northeast and Central Amazon, respectively. As expected, pioneer stem density with dbh ≥ 1 cm increased by around 10–17‐fold along forest edges regardless of species, lifespan, and study site. Edge populations of long‐lived pioneers presented 84–94 percent of their individuals in sapling/subadult size classes, whereas edge populations of short‐lived pioneers showed 56–97 percent of their individuals in adult size classes. These demographic biases were associated with negative and positive net adult recruitment of long‐ and short‐lived pioneers, respectively. Our population‐level analyses support three general statements: (1) native pioneer tree species proliferate along forest edges (i.e., increased density), at least in terms of non‐reproductive individuals; (2) pioneer response to edge establishment is not homogeneous as species differ in terms of demographic structure and net adult recruitment; and (3) some pioneer species, particularly long‐lived ones, may experience population decline due to adult sensitivity to edge‐affected habitats.     

Accumulation of “Old Proteins” and the Critical Need for MS‐based Protein Turnover Measurements in Aging and Longevity

Aging and age‐related diseases are accompanied by proteome remodeling and progressive declines in cellular machinery required to maintain protein homeostasis (proteostasis), such as autophagy, ubiquitin‐mediated degradation, and protein synthesis. While many studies have focused on capturing changes in proteostasis, the identification of proteins that evade these cellular processes has recently emerged as an approach to studying the aging proteome. With advances in proteomic technology, it is possible to monitor protein half‐lives and protein turnover at the level of individual proteins in vivo. For large‐scale studies, these technologies typically include the use of stable isotope labeling coupled with MS and comprehensive assessment of protein turnover rates. Protein turnover studies have revealed groups of highly relevant long‐lived proteins (LLPs), such as the nuclear pore complexes, extracellular matrix proteins, and protein aggregates. Here, the role of LLPs during aging and age‐related diseases and the methods used to identify and quantify their changes are reviewed. The methods available to conduct studies of protein turnover, used in combination with traditional proteomic methods, will enable the field to perform studies in a systems biology context, as changes in proteostasis may not be revealed in studies that solely measure differential protein abundances.     

Medieval monastic mortality: Hazard analysis of mortality differences between monastic and nonmonastic cemeteries in England

Scholarship on life in medieval European monasteries has revealed a variety of factors that potentially affected mortality in these communities. Though there is some evidence based on age‐at‐death distributions from England that monastic males lived longer than members of the general public, what is missing from the literature is an explicit examination of how the risks of mortality within medieval monastic settings differed from those within contemporaneous lay populations. This study examines differences in the hazard of mortality for adult males between monastic cemeteries (n = 528) and non‐monastic cemeteries (n = 368) from London, all of which date to between AD 1050 and 1540. Age‐at‐death data from all cemeteries are pooled to estimate the Gompertz hazard of mortality, and “monastic” (i.e., buried in a monastic cemetery) is modeled as a covariate affecting this baseline hazard. The estimated effect of the monastic covariate is negative, suggesting that individuals in the monastic communities faced reduced risks of dying compared to their peers in the lay communities. These results suggest better diets, the positive health benefits of religious behavior, better living conditions in general in monasteries, or selective recruitment of healthy or higher socioeconomic status individuals. Am J Phys Anthropol 152:322–332, 2013. © 2013 Wiley Periodicals, Inc.     

An investigation of age‐related changes at the acetabulum in 18th–19th century ad adult skeletons from Christ Church Spitalfields,London

The age‐markers described at the adult acetabulum by Rissech et al. (J Forensic Sci 51 (2006) 213–229) were scored in the Spitalfields collection of skeletons of documented age and sex (N = 161). The purpose of the work was as a contribution to the evaluation of the general utility of these markers for estimating age at death. To this end, their relationship both with age, and with some other factors, was investigated. The latter comprised sex, general tendency toward bone formation in periarticular soft tissue (as measured by the occurrence of diffuse idiopathic skeletal hyperostosis), and occupation (as documented for some of the males). Of the seven Rissech et al. variables, only four were found to show a statistically significant relationship with age. The correlation between a composite score derived from a linear combination of these four variables, and age was similar to or greater than correlations between age and composite scores based on other age indicators reported in the literature for Spitalfields. Male acetabula aged at a greater rate than those of females. There was no relationship with the occurrence of DISH, but for occupation, those in nonmanual professions showed greater acetabular scores‐for‐age than those in manual trades. Am J Phys Anthropol 2012. © 2012 Wiley Periodicals, Inc.     

Evaluation of the suchey–brooks method of age estimation in an Australian subpopulation using computed tomography of the pubic symphyseal surface

Despite the prominent use of the Suchey–Brooks (S–B) method of age estimation in forensic anthropological practice, it is subject to intrinsic limitations, with reports of differential interpopulation error rates between geographical locations. This study assessed the accuracy of the S–B method to a contemporary adult population in Queensland, Australia and provides robust age parameters calibrated for our population. Three‐dimensional surface reconstructions were generated from computed tomography scans of the pubic symphysis of male and female Caucasian individuals aged 15–70 years (n = 195) in Amira® and Rapidform®. Error was analyzed on the basis of bias, inaccuracy and percentage correct classification for left and right symphyseal surfaces. Application of transition analysis and Chi‐square statistics demonstrated 63.9 and 69.7% correct age classification associated with the left symphyseal surface of Australian males and females, respectively, using the S–B method. Using Bayesian statistics, probability density distributions for each S–B phase were calculated, providing refined age parameters for our population. Mean inaccuracies of 6.77 (±2.76) and 8.28 (±4.41) years were reported for the left surfaces of males and females, respectively; with positive biases for younger individuals (<55 years) and negative biases in older individuals. Significant sexual dimorphism in the application of the S–B method was observed; and asymmetry in phase classification of the pubic symphysis was a frequent phenomenon. These results recommend that the S–B method should be applied with caution in medico‐legal death investigations of Queensland skeletal remains and warrant further investigation of reliable age estimation techniques. Am J Phys Anthropol, 2013. © 2013 Wiley Periodicals, Inc.     

Differential response to larval crowding of a long‐ and a short‐lived medfly biotype

Response of endophytic fruit fly species (Tephritidae) to larval crowding is a form of scramble competition that may affect important life history traits of adults, such as survival and reproduction. Recent empirical evidence demonstrates large differences in adult life history traits, especially longevity, among Mediterranean fruit fly (Ceratitis capitata; "medfly") biotypes obtained from different regions of the world. However, whether the evolution of long lifespan is associated with response to stress induced by larval crowding has not been fully elucidated. We investigated, under constant laboratory conditions, the response of a short‐ and a long‐lived medfly biotypes to stress induced by larval crowding. Survival and development of larvae and pupae and the size of resulting pupae were recorded. The lifespan and age‐specific egg production patterns of the obtained adults were recorded. Our findings reveal that increased larval density reduced immature survival (larvae and pupae) in the short‐lived biotype but had rather neutral effects on the longed‐lived one. Only larvae of the long‐lived biotype were capable of prolonging their developmental duration under the highest crowding regime to successfully pupate and emerge as adults. Response of emerging adults to larvae crowding conditions was similar in the two medfly biotypes. Those individuals emerging from high larval density regimes had reduced longevity and fecundity. Long‐lived biotype individuals, however, appeared to suffer a higher cost in longevity compared with the short‐lived one. The importance of our findings to understand the evolution of long lifespan is discussed.