Sex and gender differences in secular trend of body size and frame indices of Lithuanians

In Lithuania, as in many other European countries, positive secular trend of body size became especially expressed at the middle of XX. century. The analysis showed the evident secular trend in height of adult Lithuanians since the end of XIX. century till 2001 from 163.5 till 181.3 cm in males and from 153.3 cm till 167.5 cm in females. Concerning growth and development of children, during the 1925-2001 period especially obvious acceleration of height was determined at the middle of adolescence due to much earlier sexual maturation at the end of XX. century. Secular trend of body height was more expressed in males of all ages, nevertheless this process stabilized in both sexes during the last decades. While comparing secular changes in BMI of adolescent Lithuanian girls and boys between the 1925-2001 period, the evident sexual differences in secular changes were determined from the middle of pubescence: the course of changes in BMI during the XX. century was nearly the same in both sexes, but at the end of XX. century older adolescent girls became obviously thinner compared with the changes of BMI in boys of the same age. A very similar trend in BMI of adult Lithuanian women since 1980 till 2002 was also detected. This phenomenon could be more related with the changes in life stile, modern-day canons for unrealistically thin female's body and strong social pressure on women today.     

Tracking variability: recent anthropometric data for croatian population and comparison with other world populations

The variability that exists within the populations of individual countries and the variability that exists between the populations of different countries are both of interest in practical application. For these reasons, a comparison is made in this work between certain anthropometric variables of our sample of Croatian population and anthropometric variables that are available for other human populations in the world of the same or a similar age. The total sample was 1,372 subjects aged from 23 to 59 years old. For the purpose of comparison, data were taken from the study "International Data on Anthropometry" which provides an overview of anthropometric variables for many world populations, as well as data from Rudan's research that was carried out on Croatian population in the late seventies of the last century. Mean value, standard deviation and coefficient of variation have been calculated for every measured parameter. A comparison between the two research samples of Croatian population fairly displays up going trend, for body mass and other bodily dimensions, formed in three decades of difference. Mean value for body height in Rudan's sample is 161.0 cm, and for Bubas's sample in this research was 170.6 cm, both values state for Croatian population but with difference of more than 30 years. Human biologists use term "secular trend" to describe alterations in the measurable characteristics of a population of humans that occur over a century. Accordingly, in adult age, the rate of gain, concerning body height, is 10 to 30 mm per decade. The changes in body proportions during recent decades are less marked than those in body size, but the relationships between stature and weight within one national group have changed significantly.     

Research on secular trends in auxology

Current status of research on secular trends in growth and maturation is considered from several perspectives. The need to define secular trends as positive, negative or absent is initially discussed. Positive secular trends, i.e., increases in size and earlier maturation, characterize the majority of the auxological literature. However, some populations have experienced negative secular trends or no trends. Positive secular trends and cessation of secular trends in stature and age at menarche are described for developed countries, followed by a brief discussion of secular changes in body proportions and composition. Data from developing countries illustrate all three types of secular trends. Some segments of the population show positive changes in size and age at menarche, while others show no evidence of secular change or negative secular trends. Finally, comparisons of estimated statures in earlier European populations suggest a negative secular trend, i.e., a decline in estimated stature from about the 11th to the 19th centuries, which is followed by a positive secular trend starting about the mid-19th century.     

Recent environmental change in North African wetland lakes: diatom and other stratigraphic evidence from nine sites in the CASSARINA Project

All nine wetland lakes in the CASSARINA North African suite of sample sites have been disturbed strongly by human activity during the 20th century. Dated lake sediment core were used to provide evidence of the extent of recent environmental change at each site. Sedimentary diatoms at seven sites were useful for inferring salinity change trends during the last century. At two sites preservation problems severely degraded the sedimentary diatom record. Sediment core integrity was otherwise established.Lithostratigraphic measurements indicated some site specific changes in soil erosion and sediment composition but, for the Egyptian Delta lakes, no physical signal synchronous with Aswan High Dam construction was found. Sedimentary diatom assemblages were generally site characteristic and halophilous taxa were common. At two sites planktonic diatoms indicated some recent eutrophication but generally the assemblages were more indicative of salinity changes. Diatom-inferred salinity trends for the seven sites typically indicated that reductions in water salinity occurred sometime during the early or mid 20th century.Rather than climate, hydrological modification of water resources is implicated as the primary driver of salinity changes during most of the 20th century. In the western North African region these modifications were mainly local land drainage and water diversion programmes to alleviate winter flooding and/or promote summer water availability. In the Delta region, the Nile has been intensively exploited since antiquity and intensively so from the late 19th century to release more fresh water for agriculture. Here, diatom records indicate that freshening began well before the Aswan High Dam but salinity fluctuations have tended to diminish during the latter part of the 20th century. A small reversal in the water freshening trend in the 1980/90s was possibly a response to land subsidence/sea-level change or to reduced freshwater supply.Freshwater supply to the sites is generally diminishing as former freshwater surpluses switch to deficit. One site (Merja Bokka, Morocco) became completely dry in 1998 as agriculture encroached and Megene Chitane, the only acid lake in Tunisia, is currently affected by excessive inflow abstraction. At the beginning of the 21st century, eight of the nine CASSARINA sites persist as viable but modified aquatic ecosystems. They nevertheless continue to support valuable aquatic biodiversity, especially in the Delta sites and in Chitane. The modern diatom communities are clearly tolerant of considerable environmental change but the remaining sites are increasingly threatened by major hydrological disturbance. Base-line floristic data for the late 20th century are given but continuous biomonitoring combined with effective management is needed urgently to help conserve North Africa's diminishing natural wetland lake resources.     

The decline in BMI among Japanese women after World War II

The body mass index (BMI) of the Japanese is significantly lower than is found in other high-income countries. Moreover, the average BMI of Japanese women is lower than that of Japanese men, and the age-specific BMI of Japanese women has decreased over time. The average BMI of Japanese women at age 25 decreased from 21.8 in 1948 to 20.4 in 2010 whereas that of men increased from 21.4 to 22.3 over the same period. We examine the long-term BMI trend in Japan by combining several historical data sources spanning eleven decades, from 1901 to 2012, to determine not only when but also how the BMI decline among women began: whether its inception was period-specific or cohort-specific. Our nonparametric regression analysis generated five findings. First, the BMI of Japanese women peaked with the 1930s birth cohort. This means that the trend is cohort-specific. Second, the BMI of men outpaced that of women in the next cohort. Third, the BMI of Japanese children, boys and girls alike, increased steadily throughout the 20th century. Fourth, the gender difference in the BMI trend is due to a gender difference in the weight trend, not the height trend. Fifth, these BMI trends are observed in urban and rural populations alike. We conclude that the BMI decline among Japanese women began with those who were in their late teens shortly after World War II.     

Secular trends in some Russian populations

Secular changes of body measurements in children have been the subject of studies in many different countries. In recent years, there has been an increase in BMI associated with a significant trend towards obesity in both Europe and the US. The aim of the present study was to analyze trends in body measurements and BMI in Russia from the 1960's to the beginning of the 21st century. This was done at three locations of the Russian Federation: the city of Moscow, the cities of Saratov and Naberezhnye Chelny in the Volga-river area. In addition, data on secular changes of Abkhazian children were analyzed. A large number of anthropometric measurements were taken on each individual including height, weight, arm, leg and trunk lengths (estimated), body diameters and circumferences, skinfold thickness, head and face dimensions. Stages of secondary sex characteristics also were evaluated; data on menarcheal age were collected by status-quo and retrospective methods. Changes in hand grip strength have been evaluated in some of the samples. While stature was increasing during these years, weight, chest circumference and BMI were characterized by negative changes, which became more obvious in elder girls. Changes in handgrip strength also showed negative trends. There were noticeable changes in head and face measurements, which were expressed in more elongated head and face forms, i.e. the head became longer and narrower with narrower and higher faces. Secular changes in head and facial morphology may be considered part of the general trend.     

Gender differences in body build and physiological functions in the adult population of Yucatan, Mexico

This study, conducted in 1994-95, evaluates differences in body build, blood pressure and respiratory functions between sexes and age groups of low socioeconomic strata individuals living in Merida, Yucatan, Mexico. The cross-sectional sample includes 344 males and 320 females, 20-98 years of age divided into six age groups (20-29, 30-39, 40-49, 50-59, 60-69 and 70+ years) by sex. Differences between age cohorts in height, weight, fatness, systolic blood pressure, and most respiratory variables (excluding expiratory reserve volume, minute ventilation and respiration rate) are greater among women than in men. The more marked secular trend in stature and bigger biological differences between age cohorts in women might have its beginning in 19th century when living conditions of women were worse than those of men. Only since the last decades of 20th century, migrations and improvements in living conditions might caused more drastic changes in women of low social strata than in men. Results of regression analysis show a greater relationship between studied variables in women than in men what confirms that women are less sensitive to environmental factors. A pattern of changes in minute ventilation (MV) with rising age of the cohorts differs between men and women (smaller differences appear in the women's cohort) Also a different pattern (MV) is seen in European populations. The latter may suggest existence of some adaptational phenomena to the local environment.     

Recent increase in body size of the American marten Martes americana in Alaska

Using museum specimens, we studied recent changes in skull size of the American marten Martes americana , in continental Alaska. In Alaska, global warming has resulted in milder winters that may contribute to an improved food supply in the wild. In the present study, we tested the hypothesis that body size of the marten had increased during the second half of the 20th century, in response to global warming. We found that skull size, and by implication body size, increased significantly during the second half of the 20th century, possibly due to an improved food supply and/or lower metabolic demands in winter. Improved food availability in winter may result from the improved nutritional conditions for prey, and/or from increased access to prey resulting from a longer snow-free season. Longitude had a significant positive effect on skull size and a significant negative effect on teeth size. In Alaska, the climate is milder along the western coast and becomes harsher inland. Hence, the milder climate was associated with larger body size providing further support for our prediction that body size of the American marten was influenced by food availability and reduced energy expenditure. The negative relationship between longitude and teeth size may indicate a trend towards a larger prey in inland marten populations, but we have no data to support or refute this hypothesis.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 93 , 701–707.     

Observations on variation in skull size of three mammals in Israel during the 20th century

Among mammals, food availability, especially during the growth period, is a key predictor in determining final body size, and improved nutrition may lead to an increase in their body size. In Israel during the last century food availability for animals commensal with humans increased greatly, due to a 16-fold increase in the human population and the accompanying changes, such as a 135-fold increase in the area of irrigated agriculture and the availability of large quantities of organic garbage.Using museum material, we studied temporal changes in skull size of a sample of 89 red foxes (Vulpes vulpes Linnaeus, 1758), 108 golden jackals (Canis aureus Linnaeus, 1758) and 117 Cape hares (Lepus capensis Linnaeus, 1758) collected during the 20th century. Four measurements (condylobasal length, zygomatic breadth, the length of the upper cheek teeth row and the length of the mandible) were taken for each skull, and principal component analysis was used to combine the measurements into principal components.We found that skull size of the red fox increased significantly during the 20th century, possibly due to improved food availability from man-made resources such as agricultural produce and garbage. No temporal trend in body size was detected for the jackal and hare. These differences are discussed.     

Twentieth century increase of Scots pine radial growth in NE Spain shows strong climate interactions

Stem radial growth responds to environmental conditions, and has been widely used as a proxy to study long‐term patterns of tree growth and to assess the impact of environmental changes on growth patterns. In this study, we use a tree ring dataset from the Catalan Ecological and Forest Inventory to study the temporal variability of Scots pine (Pinus sylvestris L.) stem growth during the 20th century across a relatively large region (Catalonia, NE Spain) close to the southern limit of the distribution of the species. Basal area increment (BAI) was modelled as a function of tree size and environmental variables by means of mixed effects models. Our results showed an overall increase of 84% in Scots pine BAI during the 20th century, consistent with most previous studies for temperate forests. This trend was associated with increased atmospheric CO₂ concentrations and, possibly, with a general increase in nutrient availability, and we interpreted it as a fertilization effect. Over the same time period, there was also a marked increase in temperature across the study region (0.19 °C per decade on average). This warming had a negative impact on radial growth, particularly at the drier sites, but its magnitude was not enough to counteract the fertilization effect. In fact, the substantial warming observed during the 20th century in the study area did not result in a clear pattern of increased summer drought stress because of the large variability in precipitation, which did not show any clear time trend. But the situation may change in the future if temperatures continue to rise and/or precipitation becomes scarcer. Such a change could potentially reverse the temporal trend in growth, particularly at the driest sites, and is suggested in our data by the relative constancy of radial growth after ca. 1975, coinciding with the warmer period. If this situation is representative of other relatively dry, temperate forests, the implications for the regional carbon balance would be substantial.     

A divergent pattern of the sex difference in life expectancy: Sweden and Japan, early 1970s-late 1990s

For most of the 20th century the sex gap in life expectancy in the industrialized countries has widened in favor of women. By the early 1980s a reversal in the long-term pattern of this differential had occurred in some countries, where it reached a maximum and thereafter followed a declining trend. Of particular interest to the present investigation is the anomalous experience of Japan, where unlike other high-income countries the female advantage in life expectancy has been expanding. We contrast the case of Japan with that of Sweden, where, like many other high-income nations, the sex differential in longevity has been narrowing in recent years. We observe that in Sweden, until the early 1980s, the sex gap in life expectancy (female-male) exceeded that of Japan; but this situation reversed in subsequent periods, when the Swedish differential narrowed and that of Japan widened. A decomposition analysis indicates that these divergent patterns since 1980 have resulted mainly from larger than expected reductions in male mortality in Sweden due to heart disease and from accidents and violence, lung cancer and "other" cancers. In Japan, death rates for men and women from heart disease--which is a leading cause of death--have tended to decline more or less at the same pace since the early 1980s; and with regard to lung cancer, and "other" neoplasms, male death rates in Japan have been rising while those of women have either declined or risen more slowly. Moreover, during the 1990s, male and female suicide rates rose in Japan, but the rates for men went up faster. Altogether, the net effect of these divergent mortality trends for men and women in Japan underlie much of the observed widening of its sex differential in longevity in recent years.     

Plant identification credibility in ethnobotany: a closer look at Polish ethnographic studies

In Italy, malaria was an endemic disease that was eradicated by the mid-20th century. This paper evaluates the prophylactic and therapeutic remedies used by folk medicine to cure malaria in Calabria (southern Italy). The data has been collected by analysing works of physicians, ethnographers, folklorists and specialists of the study of Calabrian history between the end of the 19th century and the 20th century. The data collected have allowed us to describe the most common cures used by the Calabrian people to treat malaria and the most evident symptoms of this disease, such as intermittent fever, hepato-spleenomegaly, asthenia and dropsy. This approach uncovered a heterogeneous corpus of empirical, magical and religious remedies, which the authors have investigated as evidences of past "expert medicine" and to verify their real effectiveness in the treatment of malaria.     

Determinants of variation in adult body height

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 living conditions, not only in developing countries but also in modern Western societies. Future studies combining different scientific traditions in auxology are needed to create a more holistic view of body height.     

“艺术的外貌、科学的内涵、使命的担当”——植物园500年来的科研与社会功能变迁(二):科学的内涵

世界植物园500多年来的科研行进轨迹既是整个生物学发展史的一个缩影, 也表现出人类对植物资源发掘与利用, 使之服务于经济与社会发展的不懈追求。从16-17世纪的植物园主要研究药用植物并发掘药物, 到18-20世纪以来从植物分类学逐步拓展至众多植物学分支学科, 进一步发展到当今的植物分子生物学及基因组、代谢组学等等。植物园在长达几个世纪的发展进程中, 其科学研究内涵始终贯穿其中, 既奠定了18世纪植物分类学的根基, 也对18世纪以来许多生物学发现及其理论体系的建立作出了不可磨灭的贡献。同时, 16世纪以来跨大陆、跨地区、跨国家之间的植物引种驯化及其发掘利用与传播深刻改变了世界经济社会格局, 影响了一些国家的兴衰。在近代500多年的植物引种驯化与传播过程中, 植物园发挥了引领作用。本文试图对植物园500年来的科学研究轨迹进行梳理, 展望当今植物园在植物宏观与微观生物学及其大数据时代相关研究领域的发展趋势, 为我国植物园的科研方向提供可借鉴的参考。     

Oyster (Ostrea edulis) extirpation and ecosystem transformation in the Firth of Forth,Scotland

Marine inshore communities, including biogenic habitats have undergone dramatic changes as a result of exploitation, pollution, land-use changes and introduced species. The Firth of Forth on the east coast of Scotland was once home to the most important oyster (Ostrea edulis Linnaeus, 1758) beds in Scotland. 19th and early 20th century fisheries scientists documented the degradation and loss of these beds, yet transformation of the wider benthic community has been little studied. We undertook archival searches, ecological surveys and shell community analysis using radioisotope dated sediment cores to investigate the history of decline of Forth oyster beds over the last 200 years and the changes to its wider biological communities. Quadrat analysis of the present day benthos reveal that soft-sediment communities dominate the Firth of Forth, with little remaining evidence of past oyster beds in places where abundant shell remains were picked up by a survey undertaken in 1895. Queen scallops (Aequipecten opercularis Linnaeus, 1758) and horse mussels (Modiolus modiolus Linnaeus, 1758) were once common within the Forth but have also markedly decreased compared to the earlier survey. Ouranalyses of shell remains suggest that overall mollusc biomass and species richness declined throughout the 19th century and early 20th century, suggesting broader-scale community change as human impacts increased and as habitats degraded. Inshore communities in the Firth of Forth today are less productive and less diverse compared to past states, with evidence suggesting that most of the damage was done by early bottom trawling and dredging activities. Given the pervasive nature of intensive trawling over the past 150 years, the kind of degradation we document for the Firth of Forth is likely to be commonplace within UK inshore communities.     

Libbie Henrietta Hyman (1888-1969): from developmental mechanics to the evolution of animal body plans

Libbie Hyman is the most influential comparative invertebrate zoologist of the 20th century in the English-speaking world. During the first part of her career Hyman conducted experimental research on the metabolic and developmental physiology of a host of invertebrates and vertebrate embryos. One important aim of these studies was to elucidate the hidden processes of morphogenesis. Some of the papers from this early phase of Hyman's career already contain the seeds for her subsequent occupation with comparative embryology and morphology to address questions about animal body plan evolution and metazoan phylogeny. Hyman's views on invertebrate evolution and phylogeny have become widely incorporated into textbooks, and until very recently Hyman's ideas have been equated with 'traditional' or 'classical' views on animal evolution. Hyman's enduring fame and significance for modern evo-devo is primarily based upon her magisterial six-volume series The Invertebrates, which is the most encompassing single-author synthesis of invertebrate structure and development of the 20th century. In The Invertebrates Hyman addressed numerous questions about the evolution of animal body plans and metazoan phylogeny that are nowadays core items on the research agenda of evo-devo. In addition, Hyman had a lasting influence on teaching with the publication of her widely used laboratory manuals for elementary zoology, and especially comparative vertebrate anatomy.     

Fertility decline driven by poverty: the case of Addis Ababa, Ethiopia

Demographic transition theory states that fertility declines in response to development, thus wealth and fertility are negatively correlated. Evolutionary theory, however, suggests a positive relationship between wealth and fertility. Fertility transition as a result of industrialization and economic development started in the late 19th and early 20th centuries in Western Europe; and it extended to some of the Asian and Latin American countries later on. However, economic crises since the 1980s have been co-incident with fertility decline in sub-Sahara Africa and other developing countries like Thailand, Nepal and Bangladesh in the last decade of the 20th century. A very low level of fertility is observed in Addis Ababa (TFR=1.9) where contraceptive prevalence rate is modest and recurrent famine as well as drought have been major causes of economic crisis in the country for more than three consecutive decades, which is surprising given the high rural fertility. Detailed socioeconomic and demographic characteristics of 2976 women of reproductive age (i.e. 15-49 years) residing in Addis Ababa were collected during the first quarter of 2003 using an event history calendar and individual women questionnaire. Controlling for the confounding effects of maternal birth cohort, education, marital status and accessible income level, the poor (those who have access to less than a dollar per day or 250 birr a month) were observed to elongate the timing of having first and second births, while relatively better-off women were found to have shorter birth intervals. Results were also the same among the ever-married women only model. More than 50% of women currently in their 20s are also predicted to fail to reproduce as most of the unmarried men and women are 'retreating from marriage' due to economic stress. Qualitative information collected through focus group discussions and in-depth interviews also supports the statistical findings that poverty is at the root of this collapse in fertility. Whilst across countries wealth and fertility have been negatively correlated, this study shows that within one uniform population the relationship is clearly positive.     

Growth variation, final height and secular trend. Proceedings of the 17th Aschauer Soiree, 7th November 2009

Growth and body height have always been topics interesting to the public. In particular, the stupendous increase of some 15-19 cm in final adult height during the last 150 years in most European countries (the “secular trend”), the concomitant changes in body and head proportions, the tendency towards early onset of sexual maturation, the changes in the age when final height is being reached, and the very recent trend in body mass index, have generated much scientific literature. The marked plasticity of growth in height and weight over time causes problems. Child growth references differ between nations, they tend to quickly become out of date, and raise a number of questions regarding fitting methods, effects caused by selective drop-out, etc. New findings contradict common beliefs about the primary importance of nutritional and health related factors for secular changes in growth. There appears to be a broad age span from mid-childhood to early adolescence that is characterised by a peculiar insusceptibility. Environmental factors that are known to influence growth during this age span appear to have only little or no impact on final height. Major re-arrangements in height occur at an age when puberty has almost been completed and final height has almost been reached, implying that factors, which drive the secular trend in height, are limited to early childhood and late adolescence.