Technical note: Error in Olivier and Pineau's regression formulae for calculation of stature and lunar age from radial diaphyseal length in forensic fetal remains

Stewart ([1979] Essentials of Forensic Anthropology, pp. 128–131) cites five regression formulae presented by Olivier and Pineau ([1960] Ann. Méd. Lég. 40:141–144) for estimation of fetal stature from diaphyseal length. Of these formulae, one appears problematic: the formula for calculation of stature from the radius yields values which suggest the fetus has a much greater crown-heel (CH) length than do the remaining formulae for the diaphyses of other long bones. Moreover, when this stature estimate, so derived, is then inserted into these authors' earlier general formula for estimation of lunar age (Olivier and Pineau [1958] Arch. Anat. 6:21–28) the error is compounded. A fetus is now indicated to be nearly a trimester older than when the CH lengths obtained by the other long bone formulae are used. Accordingly, we believe this particular formula, unlike the others, is incorrect and should not be used to estimate lunar age from fetal remains. © 1996 Wiley-Liss, Inc.     

A clockwork fish: Age prediction using DNA methylation‐based biomarkers in the European seabass

Age‐related changes in DNA methylation do occur. Taking advantage of this, mammalian and avian epigenetic clocks have been constructed to predict age. In fish, studies on age‐related DNA methylation changes are scarce and no epigenetic clocks have been constructed. However, in fisheries and population dynamics studies there is a need for accurate estimation of age, something that is often impossible for some economically important species with the currently available methods. Here, we used the European sea bass, a marine fish the age of which can be determined with accuracy, to construct a piscine epigenetic clock, the first one in a cold‐blooded vertebrate. We used targeted bisulfite sequencing to amplify 48 CpGs from four genes in muscle samples and applied penalized regressions to predict age. We thus developed an age predictor in fish that is highly accurate (0.824) and precise (2.149 years). In juvenile fish, accelerated growth due to elevated temperatures had no effect on age prediction, indicating that the clock is able to predict the chronological age independently of environmentally‐driven perturbations. An epigenetic clock developed using muscle samples accurately predicted age in samples of testis but not ovaries, possibly reflecting the reproductive biology of fish. In conclusion, we report the development of the first piscine epigenetic clock, paving the way for similar studies in other species. Piscine epigenetic clocks should be of great utility for fisheries management and conservation purposes, where age determination is of crucial importance.     

Age estimation in a long‐lived seabird (Ardenna tenuirostris) using DNA methylation‐based biomarkers

Age structure is a fundamental aspect of animal population biology. Age is strongly related to individual physiological condition, reproductive potential and mortality rate. Currently, there are no robust molecular methods for age estimation in birds. Instead, individuals must be ringed as chicks to establish known‐age populations, which is a labour‐intensive and expensive process. The estimation of chronological age using DNA methylation (DNAm) is emerging as a robust approach in mammals including humans, mice and some non‐model species. Here, we quantified DNAm in whole blood samples from a total of 71 known‐age Short‐tailed shearwaters (Ardenna tenuirostris) using digital restriction enzyme analysis of methylation (DREAM). The DREAM method measures DNAm levels at thousands of CpG dinucleotides throughout the genome. We identified seven CpG sites with DNAm levels that correlated with age. A model based on these relationships estimated age with a mean difference of 2.8 years to known age, based on validation estimates from models created by repeated sampling of training and validation data subsets. Longitudinal observation of individuals re‐sampled over 1 or 2 years generally showed an increase in estimated age (6/7 cases). For the first time, we have shown that epigenetic changes with age can be detected in a wild bird. This approach should be of broad interest to researchers studying age biomarkers in non‐model species and will allow identification of markers that can be assessed using targeted techniques for accurate age estimation in large population studies.     

The MiAge Calculator: a DNA methylation-based mitotic age calculator of human tissue types

Cell division is important in human aging and cancer. The estimation of the number of cell divisions (mitotic age) of a given tissue type in individuals is of great interest as it allows not only the study of biological aging (using a new molecular aging target) but also the stratification of prospective cancer risk. Here, we introduce the MiAge Calculator, a mitotic age calculator based on a novel statistical framework, the MiAge model. MiAge is designed to quantitatively estimate mitotic age (total number of lifetime cell divisions) of a tissue using the stochastic replication errors accumulated in the epigenetic inheritance process during cell divisions. With the MiAge model, the MiAge Calculator was built using the training data of DNA methylation measures of 4,020 tumor and adjacent normal tissue samples from eight TCGA cancer types and was tested using the testing data of DNA methylation measures of 2,221 tumor and adjacent normal tissue samples of five other TCGA cancer types. We showed that within each of the thirteen cancer types studied, the estimated mitotic age is universally accelerated in tumor tissues compared to adjacent normal tissues. Across the thirteen cancer types, we showed that worse cancer survivals are associated with more accelerated mitotic age in tumor tissues. Importantly, we demonstrated the utility of mitotic age by showing that the integration of mitotic age and clinical information leads to improved survival prediction in six out of the thirteen cancer types studied. The MiAge Calculator is available at http://www.columbia.edu/～sw2206/softwares.htm.     

Epigenetic estimation of age in humpback whales

Age is a fundamental aspect of animal ecology, but is difficult to determine in many species. Humpback whales exemplify this as they have a lifespan comparable to humans, mature sexually as early as 4 years and have no reliable visual age indicators after their first year. Current methods for estimating humpback age cannot be applied to all individuals and populations. Assays for human age have recently been developed based on age‐induced changes in DNA methylation of specific genes. We used information on age‐associated DNA methylation in human and mouse genes to identify homologous gene regions in humpbacks. Humpback skin samples were obtained from individuals with a known year of birth and employed to calibrate relationships between cytosine methylation and age. Seven of 37 cytosines assayed for methylation level in humpback skin had significant age‐related profiles. The three most age‐informative cytosine markers were selected for a humpback epigenetic age assay. The assay has an R² of 0.787 (P = 3.04e?16) and predicts age from skin samples with a standard deviation of 2.991 years. The epigenetic method correctly determined which of parent–offspring pairs is the parent in more than 93% of cases. To demonstrate the potential of this technique, we constructed the first modern age profile of humpback whales off eastern Australia and compared the results to population structure 5 decades earlier. This is the first epigenetic age estimation method for a wild animal species and the approach we took for developing it can be applied to many other nonmodel organisms.     

Combining capture–recapture data and known ages allows estimation of age‐dependent survival rates

In many animal populations, demographic parameters such as survival and recruitment vary markedly with age, as do parameters related to sampling, such as capture probability. Failing to account for such variation can result in biased estimates of population‐level rates. However, estimating age‐dependent survival rates can be challenging because ages of individuals are rarely known unless tagging is done at birth. For many species, it is possible to infer age based on size. In capture–recapture studies of such species, it is possible to use a growth model to infer the age at first capture of individuals. We show how to build estimates of age‐dependent survival into a capture–mark–recapture model based on data obtained in a capture–recapture study. We first show how estimates of age based on length increments closely match those based on definitive aging methods. In simulated analyses, we show that both individual ages and age‐dependent survival rates estimated from simulated data closely match true values. With our approach, we are able to estimate the age‐specific apparent survival rates of Murray and trout cod in the Murray River, Australia. Our model structure provides a flexible framework within which to investigate various aspects of how survival varies with age and will have extensions within a wide range of ecological studies of animals where age can be estimated based on size.     

A cross-setting study of chimpanzee (Pan troglodytes) personality structure and development: zoological parks and Yerkes National Primate Research Center

This study addressed whether personality ratings using a 43 adjective questionnaire based on the Five-Factor Model generalized from a sample of 202 zoo-housed chimpanzees to a sample of 175 chimpanzees housed in Yerkes National Primate Research Center. Mean interrater reliabilities of adjectival ratings were lower for the chimpanzees housed in Yerkes. In addition, rank order of the interrater reliabilities of items differed between settings. To compare factor structure, we first examined whether we could replicate the original six factor structure found in an earlier study of 100 zoo chimpanzees using principal factors analysis in the Yerkes sample and 102 new zoo chimpanzees. The dominance, extraversion, conscientiousness, and agreeableness factors were clearly replicated in the Yerkes sample and the 102 new zoo chimpanzees. The Neuroticism and Openness factors did not replicate in the Yerkes sample, but they also did not replicate in the new zoo chimpanzees. These findings suggest the need to sample more adjectives representing neuroticism and openness in future versions of the questionnaire. We next sought to determine whether factor structure, as determined by principal components analysis, remained invariant across the two settings. This analysis revealed dominance, extraversion, conscientiousness, and agreeableness factors in both settings and a high level of congruence between the zoo and Yerkes samples for these factors. Finally, we tested whether factor scores in the two samples were similarly related to age and sex. With the exception of differences in age effects for dominance and agreeableness, age, and sex effects were consistent across samples. These findings suggest that, whereas there may be differences in the ease with which ratings are made, personality structure, and development are largely consistent across widely differing settings.     

柳江化石智人的身高

作者将柳江人的右侧股骨残段作了复原。根据华南人由肢骨测量身高的公式,如果柳江人股骨属男性,其身高为156.69±3.74厘米,比现代当地居民的平均身高偏矮。     

Secondary osteon and Haversian canal dimensions as behavioral indicators

Variation in the size of structures within mature cortical bone is relevant to our understanding of apparent differences between human samples, and it is relevant to the development of histologically based age-estimation methods. It was proposed that variation may reflect effects of physical activity, through biomechanical and/or metabolic mechanisms. If these factors are local, femoral osteon area (On.Ar) should be more histologically variable than On.Ar in ribs. Ribs should show a higher variation in Haversian canal area (H.Ar) if they are sites of more remodeling activity and hence of arrested refilling of secondary osteons at time of death. This study compares On.Ar and H.Ar of secondary osteons from femora (15) and ribs (29) from 44 Holocene (Later Stone Age) foragers from South Africa (M = 19, F = 25) to values from paired femora and ribs from historic samples (Spitalfields and St. Thomas, 20 pairs from each). Fixed-effects analysis of variance demonstrates rib On.Ar to be significantly smaller than femur, but with no sex or age effects. The femur-to-rib On.Ar ratio is lower for the Holocene foragers than for the two modern samples because of relatively large rib On.Ar. Femora and ribs from the same skeleton normally show femoral On.Ar larger than rib On.Ar (37/44 pairs). Mean femoral values of On.Ar are more diverse than rib On.Ar values, but within-sample coefficients of variation are similar. Values for H.Ar are highly variable and do not reflect anatomical site, age, sex, or population effects. The patterning of osteon size does not appear to be linked to physical activity or to different rates of metabolic activity within the skeleton, at least not in a straightforward way.     

Probabilistic approach to age estimation of children by dental maturation

Two probabilist methods of age prediction in children are proposed: they are both based on the radiological presence of erupted teeth or germs. Using an apprenticeship sample of known age and sex, we established several discriminant models (+/- 13, +/- 16, +/- 18 years old). We also evaluated a Bayesian model with the following age groups: < 13, [13-16[, [16-18[, > or = 18 years old, or [X and Y] years old. When applied on a known test sample, Fisher's linear functions presented a success rate greater than 90%, above 13 years threshold, and below 16 and 18 years thresholds, and Bayesian approach, greater than 85%. Therefore, these methods provide an interesting alternative for children age determination that can be applied in biological and forensic anthropology, too.     

Estimating age from adult occlusal wear: A modification of the miles method

The Miles method of age estimation relies on molar wear to estimate age and is widely used in bioarcheological contexts. However, because the method requires physical seriation and a sample of subadults to estimate wear rates it cannot be applied to many samples. Here, we modify the Miles method by scoring occlusal wear and estimating molar wear rates from adult wear gradients in 311 hunter‐gatherers and provide formulae to estimate the error associated with each age estimate. A check of the modified method in a subsample (n = 22) shows that interval estimates overlap in all but one case with age categories estimated from traditional methods; this suggests that the modifications have not hampered the ability of the Miles method to estimate age even in heterogeneous samples. As expected, the error increases with age and in populations with smaller sample sizes. These modifications allow the Miles method to be applied to skeletal samples of adult crania that were previously only amenable to cranial suture age estimation, and importantly, provide a measure of uncertainty for each age estimate. Am J Phys Anthropol 149:181–192, 2012. © Wiley Periodicals, Inc.     

Linkage analysis and association analysis in the presence of linkage using age at onset of COGA alcoholism data

Complex disease mapping usually involves a combination of linkage and association techniques. Linkage analysis can scan the entire genome in a few hundred tests. Association tests may involve an even greater number of tests. However, association tests can localize the susceptibility genes more accurately. Using a recently developed combined linkage and association strategy, we analyzed a subset of the Collaborative Study on the Genetics of Alcoholism (COGA) data for the Genetic Analysis Workshop 14 (GAW14). In this analysis, we first employed linkage analysis based on frailty models that take into account age of onset information to establish which regions along the chromosome are likely to harbor disease susceptibility genes for alcohol dependence. Second, we used an association analysis by exploiting linkage disequilibrium to narrow down the peak regions. We also compare the methods with mean identity-by-descent tests and transmission/disequilibrium tests that do not use age of onset information.     

指纹与年龄相关性的量化分析

本文利用Leica M125体视显微镜对1510份样本中右手拇指的皱纹、乳突纹线密度、乳突纹线和小犁沟的宽度、细点线、屈肌褶纹等特征进行测量,通过SPSS软件分析年龄信息特征的相关性,选取其中相关性大的变量进行多元线性回归,并得出推断公式以分析并量化随年龄的增长指纹与年龄相关信息的变化特点及规律。研究结果显示,手印中的皱纹、乳突纹线密度、乳突纹线和小犁沟的宽度、细点线、屈肌褶纹等特征与年龄具有相关性,但利用这些变量构建的多元回归模型拟合优度并不高;皱纹、乳突纹线密度、乳突纹线和小犁沟的宽度、细点线、屈肌褶纹等可作为手印分析年龄的参考和辅助特征。乳突纹线的边缘形态、手印印痕的模糊程度、汗孔等以当前科技手段难以用测量描述特征的年龄信息,在手印分析年龄中或可发挥核心价值,具体还需进一步探究。     

Transition analysis: a validation study with known-age modern American skeletons

Transition Analysis-a recent skeletal age-estimation procedure (Boldsen et al.: Paleodemography: age distributions from skeletal samples (2002) 73-106)-is evaluated using 252 known-age modern American males and females from the Bass Donated Collection and Mercyhurst forensic cases. The pubic symphysis worked best for estimating age, followed by the sacroiliac joint and cranial sutures. Estimates based on all skeletal characteristics are influenced by the choice of prior distribution, although its effect is dwarfed by both the inaccuracy and imprecision of age estimates. Age intervals are narrowest for young adults, but are surprisingly short in old age as well. When using an informative prior distribution, the greatest uncertainty occurs from the late 40s into the 70s. Transition Analysis estimates do not perform as well as experience-based assessments, indicating the existing procedure is too narrowly focused on commonly used pelvic and cranial structures.     

Estimating cladoceran birth rate: use of the egg age distribution to estimate mortality of ovigerous females and eggs

The birth rate of natural cladoceran populations can change rapidly (during 2–3 days), reflecting rapid changes in their environment. If the egg ratio is calculated on the basis of egg age distribution, the birth rate can be estimated at short sampling intervals (shorter than egg stage duration) by modified Paloheimo's (1974) formula. When female size structure and age of eggs in clutches at the beginning and the end of a sampling interval are known, death rates of ovigerous females and eggs in separate size classes can be determined and incorporated in birth rate estimates. All these methods have been employed using the data on the population of Diaphanosoma brahyurum from the lake Obsterno (North-Western Belarus) in July–August, 1992. The birth rate values computed by the proposed methods and Poloheimo's formula differed significantly in many cases. The accuracy of birth rate estimations from various calculation methods was tested using a computer simulation. The model contains the essential features of cladoceran life history: distinct egg, juvenile and adult stages, development of eggs and reproduction. The population was divided into 25 age classes, each of 1 day duration. Durations of the egg, juvenile and adult stages were set at 3, 6 and 20 days, respectively. The embryogenesis was divided into three egg stages, each of 1 day duration. Survivorship was set from 0.2 up to 1.0 for each age class. The survivorship and brood size were changed through each of five time intervals (days) that allowed to simulate an increase or reduction of population density. Fecundity, survivorship and egg stage duration remained constant during each of 5 days that assumed stability of an environment (this does not occur in nature). Nevertheless, the egg ratio, proportion of juveniles and birth rates were variable even under these circumstances. Computer simulations showed that Poloheimo's formula evaluates birth rate with the relative error of 62% and usually overestimates its values. We propose methods to decrease errors of birth rate estimations by 3.5–5.5 times.     

Estimating Body Composition in Adolescent Sprint Athletes: Comparison of Different Methods in a 3 Years Longitudinal Design

A recommended field method to assess body composition in adolescent sprint athletes is currently lacking. Existing methods developed for non-athletic adolescents were not longitudinally validated and do not take maturation status into account. This longitudinal study compared two field methods, i.e., a Bio Impedance Analysis (BIA) and a skinfold based equation, with underwater densitometry to track body fat percentage relative to years from age at peak height velocity in adolescent sprint athletes. In this study, adolescent sprint athletes (34 girls, 35 boys) were measured every 6 months during 3 years (age at start = 14.8 ± 1.5yrs in girls and 14.7 ± 1.9yrs in boys). Body fat percentage was estimated in 3 different ways: 1) using BIA with the TANITA TBF 410; 2) using a skinfold based equation; 3) using underwater densitometry which was considered as the reference method. Height for age since birth was used to estimate age at peak height velocity. Cross-sectional analyses were performed using repeated measures ANOVA and Pearson correlations between measurement methods at each occasion. Data were analyzed longitudinally using a multilevel cross-classified model with the PROC Mixed procedure. In boys, compared to underwater densitometry, the skinfold based formula revealed comparable values for body fatness during the study period whereas BIA showed a different pattern leading to an overestimation of body fatness starting from 4 years after age at peak height velocity. In girls, both the skinfold based formula and BIA overestimated body fatness across the whole range of years from peak height velocity. The skinfold based method appears to give an acceptable estimation of body composition during growth as compared to underwater densitometry in male adolescent sprinters. In girls, caution is warranted when interpreting estimations of body fatness by both BIA and a skinfold based formula since both methods tend to give an overestimation.     

Using molt cycles to categorize the age of tropical birds: an integrative new system

ABSTRACT Accurately differentiating age classes is essential for the long‐term monitoring of resident New World tropical bird species. Molt and plumage criteria have long been used to accurately age temperate birds, but application of temperate age‐classification models to the Neotropics has been hindered because annual life‐cycle events of tropical birds do not always correspond with temperate age‐classification nomenclature. However, recent studies have shown that similar molt and plumage criteria can be used to categorize tropical birds into age classes. We propose a categorical age‐classification system for tropical birds based on identification of molt cycles and their inserted plumages. This approach allows determination of the age ranges (in months) of birds throughout plumage succession. Although our proposed cycle‐based system is an improvement over temperate calendar‐based models, we believe that combining both systems provides the most accurate means of categorizing age and preserving age‐related data. Our proposed cycle‐based age‐classification system can be used for all birds, including temperate species, and provides a framework for investigating molt and population dynamics that could ultimately influence management decisions.     

Brief communication: A test and correction of the clavicle method of Stout and Paine for histological age estimation of skeletal remains

The histological method developed by Stout and Paine ([1992] Am. J. Phys. Antropol. 87:111–115) for estimating age at death using the clavicle is tested on a known age independent sample from a nineteenth century cemetery near Spitalfriedhof St. Johann in Basel, Switzerland. The mean absolute difference between reported ages and histologically predicted ages is 5.5 years. Mean predicted age for the sample is different from mean reported age. This difference is accounted for by differences in the age distributions between the original autopsy sample used to derive the histological age-predicting formula and the cemetery sample, and an inherent loss of reliability of histological age predictions for the skeletal remains of older individuals. A new formula based upon the combined original autopsy sample of Stout and Paine (1992) and the Swiss cemetery sample is presented. It is recommended that this formula be used when estimating ages for older individuals or archaeological skeletal samples. © 1996 Wiley-Liss, Inc.     

Hand Preferences for Bimanual Coordination in 77 Bonobos (<Emphasis Type="Italic">Pan paniscus</Emphasis>): Replication and Extension

The literature on manual laterality in nonhuman primates provides inconsistent and inconclusive findings and is plagued by methodological issues (e.g., small samples, inconsistency in methods, inappropriate measures) and gaps. Few data are available on bonobos and these are only from small samples and for relatively simple tasks. We examined laterality in a large sample of bonobos for a complex task. We tested 48 bonobos from Lola Ya Bonobo sanctuary (DR Congo) in an extension of our previous study of 29 bonobos from 3 European zoos. We assessed hand preferences using the tube task, which involves bimanual coordination: one hand extracts food from a tube that is held by the other hand. This task is a good measure of laterality and it has been used in other studies. We recorded events (frequency) and independent bouts of food extraction. We found significant manual laterality, which was not influenced by the settings or rearing history. We observed little effect of sex and found an influence of age, with greater right hand use in adults. The laterality was marked, with strong preferences and most individuals being lateralized (when analyzing frequency). We found individual preferences, with no group-level bias, even when we combined the data from the sanctuary and the zoos to enlarge the sample to 77. These first data, for a complex task and based on a large sample, are consistent with previous findings in bonobos and in other nonhuman primate species for a variety of tasks. They suggest that, despite particular features in terms of proximity to humans, language and bipedalism, bonobos do not display a laterality that is more marked or more similar to human handedness compared to that of other nonhuman primate species.