A Critical Review of the Methodology for the Study of Secular Change Using Skeletal Data (original) (raw)
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Secular Changes in Childhood, Adolescent and Adult Stature
Nestlé Nutrition Institute Workshop Series, 2013
This essay provides a brief history of the etymology and usage of the phrase 'secular change' followed by a description of secular changes in height and relative leg length in childhood, adolescence, and adulthood. Both positive and negative changes are described. Possible causes are reviewed, with an emphasis on nutrition, infection and social-economic-political (SEP) environments. The case of the Maya people living in Mexico, Guatemala, and the United States is given, which shows that intergenerational changes in stature and its components -leg length and upper body length -may occur in different directions and at different rates. The deleterious consequences of rapid catch-up growth after birth have been proposed as a hypothesis to explain the 150 years of positive secular change in height of populations in the richer nations. That hypothesis is found to be an incomplete explanation. Growth changes better track the rate of change in SEP factors. Epigenetic assimilation is a new hypothesis, which focuses on those epigenetic processes regulating gene expression, metabolic function, physiology, and behavior. Epigenetic assimilation shows promise to account for plasticity and intergenerational changes in human growth and development phenotypes.
American Journal of Physical Anthropology, 1984
Age-specific secular trend patterns for children in industrialized world regions have a regular pattern, beginning low at age 6 and increasing to a maximum at age 10 to 14, then declining. While magnitude differs, the patterns are ordinarily parallel, especially in the female samples. However, age-specific secular trend values for children from developing regions, or from areas of industrialized countries not benefitting substantially from development, are irregular in pattern and magnitude. Consequently, it is difficult to predict age at maximal secular change. We suggest that fluctuating environmental circumstances in these developing countries influence growth and, hence, the pattern of secular trend. As more stable environmental conditions relating to growth are present in the industrialized countries, this leads to more stable patterns of growth and age-specific patterns of secular change.
Adult stature variation is commonly attributed to differential stress-levels during development. However, due to selective mortality and heterogeneous frailty, a population's tall stature may be more indicative of high selective pressures than of positive life conditions. This article examines stature in a biocultural context and draws parallels between bioarchaeological and living populations to explore the multidimensionality of stature variation in the past. This study investigates: 1) stature differences between archaeological populations exposed to low or high stress (inferred from skeletal indicators); 2) similarities in growth retardation patterns between archaeological and living groups; and 3) the apportionment of variance in growth outcomes at the regional level in archaeological and living populations. Anatomical stature estimates were examined in relation to skeletal stress indicators (cribra orbitalia, porotic hyperostosis, linear enamel hypoplasia) in two medieval bioarchaeological populations. Stature and biocultural information were gathered for comparative living samples from South America. Results indicate 1) significant (P < 0.01) differences in stature between groups exposed to different levels of skeletal stress; 2) greater prevalence of stunting among living groups, with similar patterns in socially stratified archaeological and modern groups; and 3) a degree of regional variance in growth outcomes consistent with that observed for highly selected traits. The relationship between early stress and growth is confounded by several factorsincluding catch-up growth, cultural buffering, and social inequality. The interpretations of early life conditions based on the relationship between stress and stature should be advanced with caution.
Archaeological and Anthropological Sciences, 2016
Analyses of stature variation in prehistoric and historical populations encounter considerable problems of reliability of the comparisons. To properly compare the results of different studies, it is necessary to conduct a systematic review of the chronological and cultural context of the skeletal series used and identify the most approprriate method to calculate stature values, since stature reconstruction formulae are specific for certain times and places.Stature variations in the population of Sardinia (a Mediterranean island now part of the Italian republic but considered separately given its unique genetic structure) from the Neolithic to the Modern Period were studied to evaluate the intensity of millennial changes. The results were then compared with the values of coeval skeletal series reported in the literature for other Southern European countries (Italy, Spain, Portugal). We used Sardinian skeletal series with radiocarbon dates of from culturally well-defined archaeological contexts. The osteometric measurements were taken on femora of adults who had completed growth and who did not present evident pathological conditions. The data we collected and analyzed indicate that the conditions are lacking to reliably identify a common trend in millennial changes among the considered populations of Southern Europe.
Population history and ecology, in addition to climate, influence human stature and body proportions
Scientific Reports, 2021
Worldwide variation in human stature and limb proportions is widely accepted to reflect thermal adaptation, but the contribution of population history to this variation is unknown. Furthermore, stature and relative lower limb length (LLL) show substantial plastic responses to environmental stressors, e.g., nutrition, pathogen load, which covary with climate. Thus ecogeographic patterns may go beyond temperature-based selection. We analysed global variation in stature, sitting height and absolute and relative LLL using large worldwide samples of published anthropometric data from adult male (n = 571) and female (n = 268) populations in relation to temperature, humidity, and net primary productivity (NPP). Population history was modeled using spatial eigenvector mapping based on geographic distances reflecting the hypothesized pattern for the spread of modern humans out of Africa. Regression models account for ~ 50% of variation in most morphological variables. Population history expl...
Secular change in height, sitting height and leg length in rural Oaxaca, southern Mexico: 1968–2000
Annals of Human Biology, 2004
Objective: To evaluate secular changes in height, sitting height and estimated leg length between 1968 and 2000 in residents in a rural Zapotec-speaking community in Oaxaca, southern Mexico. Materials and methods: Height and sitting height were measured in school children 6-13 was estimated as height minus sitting height. The sitting height/ height ratio was calculated. Subjects were grouped by sex into four age categories: 6-9, 10-13, 13-17 and 19-29 years for analysis. The Preece-Baines Model I growth curve was fitted to cross-sectional means for 1978 and 2000. Results: There were no differences between children 6-9 and 10-13 years in 1968 and 1978 with the exception of the sitting height ratio in girls 6-9 years. Children of both sexes 6-13 years and adolescent boys 13-17 years were significantly larger in the three dimensions in 2000 compared to 1978; adolescent girls differed only in height and sitting height. Adult males in 2000 were significantly taller with longer legs than those in 1978, but the samples did not differ in sitting height and the ratio. Adult females in 1978 and 2000 did not differ significantly in the three dimensions. Rates of secular change in height and sitting height between 1978 and 2000 were reasonably similar in the three age groups of male children and adolescents, but the rate for estimated leg length was highest in 10-13-year-old boys. Secular gains were smaller in adult males, but were proportionally greater in estimated leg length. Girls 6-9 and 10-13 years experienced greater secular gains in height, sitting height and estimated leg length than adolescent and young adult females, while secular gains and rates decreased from adolescent girls to young adult women. Ages of peak velocity for height, sitting height and estimated leg length declined in boys, while only ages of peak velocity for height and estimated leg length declined in girls. Conclusions: There are major secular increases in height, sitting height and estimated leg length of children and adolescents of both sexes since 1978. Secular gains in height are of similar magnitude in boys and girls 6-13 years, but are greater in adolescent and young adult males than females. The secular increase in height of young adults of both sexes is smaller than that among adolescents. Estimated leg length accounts for about 60% of the secular increase in height in children of both sexes. Estimated leg length and sitting height contribute equally to the secular increase in height in adolescent boys, whereas estimated leg length accounts for about 70% of the secular increase in height in young adult males. Sitting height contributes about two-thirds of the secular increase in height in adolescent and young adult females.
Reconstructing stature is at the core of providing information on unidentified human remains. This research shows that there are significant differences between modern populations and those used to create the most common stature estimation formulae. New formulae for the femur and fibula in males and females were created to provide accurate estimates for modern forensic cases. Additionally, a novel measurement of the femur is shown to be moderately correlated with stature and stature estimation formulae for this measurement are included.
Determinants of Variation in Adult Body Height
Journal of Biosocial Science, 2003
Final body height is achieved as the result of a combination of genetic and environmental factors. The aim of this article is to review past studies on body height that have followed different scientific traditions. In modern Western societies, about 20% of variation in body height is due to environmental variation. In poorer environments, this proportion is probably larger, with lower heritability of body height as well as larger socioeconomic body height differences. The role of childhood environment is seen in the increase in body height during the 20th century simultaneously with the increase in the standard of living. The most important non-genetic factors affecting growth and adult body height are nutrition and diseases. Short stature is associated with poorer education and lower social position in adulthood. This is mainly due to family background, but other environmental factors in childhood also contribute to this association. Body height is a good indicator of childhood li...
Economics & Human Biology, 2008
A trend of increasing adult height has been observed in European populations since the middle of the nineteenth century (Komlos, 1985; Floud, 1989), such that, when they reach adult height, children are on average taller than their same-sex parent (Cole, 2003). Such trends have been referred to as secular trends, and defined as ''changes in growth and development of successive generations living in the same territories'' (Ulijaszek, 1998). The major influences on these secular trends are the affluence and health of populations, therefore trends in height and health outcomes can be linked. In times of hardship, in particular during wars, the secular trend may slow or reverse and this may then be followed by a period of quickening of the trend when conditions improve (