Historical effects on beta diversity and community assembly in Amazonian trees

We present a unique perspective on the role of historical processes in community assembly by synthesizing analyses of species turnover among communities with environmental data and independent, population genetic-derived estimates of among-community dispersal. We sampled floodplain and terra firme communities of the diverse tree genus Inga (Fabaceae) across a 250-km transect in Amazonian Peru and found patterns of distance-decay in compositional similarity in both habitat types. However, conventional analyses of distance-decay masked a zone of increased species turnover present in the middle of the transect. We estimated past seed dispersal among the same communities by examining geographic plastid DNA variation for eight widespread Inga species and uncovered a population genetic break in the majority of species that is geographically coincident with the zone of increased species turnover. Analyses of these and 12 additional Inga species shared between two communities located on opposite sides of the zone showed that the populations experienced divergence 42,000-612,000 y ago. Our results suggest that the observed distance decay is the result not of environmental gradients or dispersal limitation coupled with ecological drift--as conventionally interpreted under neutral ecological theory--but rather of secondary contact between historically separated communities. Thus, even at this small spatial scale, historical processes seem to significantly impact species' distributions and community assembly. Other documented zones of increased species turnover found in the western Amazon basin or elsewhere may be related to similar historical processes.

The effect of Rh-negative disease on perinatal mortality: some evidence from the Skellefteå region, Sweden, 1860-1900

The Rh-negative gene is a well-known cause of perinatal mortality. In this article, we analyze the possible role of Rh disease in perinatal mortality and stillbirths in a particular historical setting: the Skellefteå region in northern Sweden between 1860 and 1900. The data used for the study cover 23,067 children born to 4,943 women. The exact impact is not possible to establish using historical data, but the typical pattern of the disease allows us to make estimations. The expected levels based on knowledge of blood group distribution, the risk of sensitization from Rh incompatability, and the risk of perinatal mortality in births by sensitized mothers are compared with the observed levels. The results show that Rh disease was important for perinatal mortality and clustering of deaths within families.

How did women count? A note on gender-specific age heaping differences in the sixteenth to nineteenth centuries

The role of human capital in economic growth is now largely uncontested. One indicator of human capital frequently used for the pre-1900 period is age heaping, which has been increasingly used to measure gender-specific differences. In this note, we find that in some historical samples, married women heap significantly less than unmarried women. This is still true after correcting for possible selection effects. A possible explanation is that a percentage of women adapted their ages to that of their husbands, hence biasing the Whipple index. We find the same effect to a lesser extent for men. Since this bias differs over time and across countries, a consistent comparison of female age heaping should be made by focusing on unmarried women.

Reproductive behavior during the pre-transitional period: evidence from rural Bologna

A longitudinal, micro-level study of the effect of socioeconomic transformations on fertility mechanisms in the rural hinterland of Bologna between 1818 and 1900 (the beginning of the demographic transition) demonstrates that the premature death of a last-born child reduces the interval between two consecutive childbirths. Thus does it confirm the importance of breast-feeding in determining birth spacing. Women living in complex sharecropping households experienced a significantly higher risk of childbirth than did women in families headed by daily wage earners. In addition, the reproductive behavior of sharecroppers seemed to be substantially invariant to short-term ºuctuations in prices, whereas the laborers' group experienced a negative price effect. Both descriptive and multivariate analyses indicate a slight and gradual decrease in fertility levels during the period in question.

Adolescent mortality at Winchester College, 1393-1540: new evidence for medieval mortality and methodological considerations for historical demography

This article presents new data on mortality in the late medieval period, and suggests methodologies for analysing incomplete datasets. Using data collated from the records of Winchester College this study follows the lives of 2,692 individuals, and analyses adolescent mortality in the sample group for the period 1393-1540. This study of mortality among 10-18 year olds is the first of its kind to produce data for a sample of adolescents in late medieval England, and thereby contributes significant new data to our understanding of late medieval mortality. These data are placed within the context of that obtained for other medieval population samples, most notably with studies of medieval monastic groups.

A demographic explanation for the recent rise in European fertility

Between 1998 and 2008 European countries experienced the first continent-wide increase in the period total fertility rate (TFR) since the 1960s. After discussing period and cohort influences on fertility trends, we examine the role of tempo distortions of period fertility and different methods for removing them. We highlight the usefulness of a new indicator: the tempo- and parity-adjusted total fertility rate (TFRp*). This variant of the adjusted total fertility rate proposed by Bongaarts and Feeney also controls for the parity composition of the female population and provides more stable values than the indicators proposed in the past. Finally, we estimate levels and trends in tempo and parity distribution distortions in selected countries in Europe. Our analysis of period and cohort fertility indicators in the Czech Republic, Netherlands, Spain, and Sweden shows that the new adjusted measure gives a remarkable fit with the completed fertility of women in prime childbearing years in a given period, which suggests that it provides an accurate adjustment for tempo and parity composition distortions. Using an expanded dataset for ten countries, we demonstrate that adjusted fertility as measured by TFRp* remained nearly stable since the late 1990s. This finding implies that the recent upturns in the period TFR in Europe are largely explained by a decline in the pace of fertility postponement. Other tempo-adjusted fertility indicators have not indicated such a large role for the diminishing tempo effect in these TFR upturns. As countries proceed through their postponement transitions, tempo effects will decline further and eventually disappear, thus putting continued upward pressure on period fertility. However, such an upward trend may be obscured for a few years by the effects of economic recession.

Is sibling rivalry fatal?: siblings and mortality clustering

Evidence drawn from nineteenth-century Belgian population registers shows that the presence of similarly aged siblings competing for resources within a household increases the probability of death for children younger than five, even when controlling for the preceding birth interval and multiple births. Furthermore, in this period of Belgian history, such mortality tended to cluster in certain families. The findings suggest the importance of segmenting the mortality of siblings younger than five by age group, of considering the presence of siblings as a time-varying covariate, and of factoring mortality clustering into analyses.

[Demographic and epidemiological quantification in Balearic hygienism, 1850-1930]

At the end of the 19th century, social medicine promoted the use of quantification as a means to evaluate the health status of populations. In Majorca, hygienists such as the physicians Enric Fajarnés, Bernat Riera, Antoni Mayol and Emili Darder and the civil engineer Eusebi Estada sought a better understanding of health status by considering the population growth, the demographic and epidemiological profile and the influence of weather on mortality. These calculations showed that the Balearic population had a good health status in comparison to the population of mainland Spain, although less so in the international context. These results were explained by the benevolence of the insular climate, a factor that would also guarantee the success of the public health reforms proposed.

Socioeconomic marriage differentials in Australia and New Zealand

While marriage rates are relatively stable among better-educated men and women, they are rapidly declining among those with low educational attainment. This development has been recognized in the US as a new socioeconomic pattern of marriage. This article uses census data to show that socioeconomic marriage differentials are also increasing in Australia and New Zealand. These differentials have previously been noted independently of each other and of the international picture. In synthesizing the antipodean data, the article documents the new socioeconomic marriage pattern as an international phenomenon. This article further considers the extent to which the available explanations for the new marriage pattern fit the antipodean setting. In general, the factors identified as important in the North American setting are applicable to both Australia and New Zealand. In particular, the poor marriage prospects of men with low educational attainment appear to be common to these post-industrial economies with minimalist welfare states.

Toward a comprehensive demography: rethinking the research agenda on change and response

This essay drafts a new interdisciplinary agenda for research on population and development. Starting from Kingsley Davis's 1963 formulation of change and response, Davis's analytical categories are broadened to include inertia as well as change and to encompass both demographic and non-demographic responses at the micro, meso, and macro levels. On that basis the essay proposes what can be called a comprehensive demography, an approach drawing principally on micro-level methodologies like those employed in anthropological demography. Like anthropological demography, comprehensive demography questions the rationality of actors, emphasizes cultural infuences, and stops short of the postmodernist extremes of anthropology. But it also takes explicit account of higher-level social, economic, and political factors bearing on demographic behavior and outcomes. The conclusion raises some epistemological issues. Illustrative examples are offered throughout to demonstrate the feasibility of the approach, mainly referring to sub-Saharan africa and the Caribbean and often drawn from the authors' own fieldwork.

Policy experiment in Russia: cash-for-babies and fertility change

Population decline in modern day Russia is alarmingly steep: Russia loses approximately 750 thousand people each year. To combat population decline, the Russian government instituted aggressive pro-natalist policies. The paper evaluates the capacity of new policies to change women's reproductive behavior using a socio-institutionalist theoretical framework, which analyzes the gendered interaction between the states, the labor market, and family. The paper arrives to a disappointing conclusion that while efforts to improve fertility are quite aggressive, new policies do not challenge gendered hierarchies neither in public nor in private spheres, which will further depress fertility rates of Russian women.

Exploring Thailand's mortality transition with the aid of life tables

The project Thai Health-Risk Transition: A National Cohort Study seeks to better understand the health implications of modernisation and globalisation forces impacting on Thailand. As part of its "look-back" component this paper seeks, using available life tables, to document the country's post-war mortality transition. The onset of transition through mass campaigns of the late 1940s and 1950s is first discussed before attention turns to the life tables. They are predictably far from flawless, but careful analysis does permit trends that have seen around 30 years added to life expectancy to be traced, and age patterns of improved survivorship and their relation to initiatives to improve health to be examined. The broad benefits generated by mass campaigns, ongoing improvements in infant and early childhood mortality, and a phased impact of the expansion of primary health care in rural areas on adult survival prospects after the mid-1970s are demonstrated. The paper also investigates the consequences for mortality of a motorcycle-focused rapid increase in road fatalities in the late 1980s and early 1990s and the HIV/AIDS epidemic that developed after 1984.

The case of the missing girls: sex ratios in fifteenth-century Tuscany

This article addresses the apparent shortage of women in the 1427 Florentine Catasto, perhaps the most complete premodern European demographic source. It argues that the shortage exists because it was only when they entered their first marriage that Tuscan women were viewed as complete, gendered beings by their families, government officials, and society. Before marriage, a woman’s place within the household, her gender, and even her existence were liminal, at least in Tuscan documents. The result is that the ratio of men to women is more balanced for that portion of the population past the age of marriage for women. Shifting the analysis from infants and men, where it has traditionally lain, to young adult women explains the gender imbalance in the documentation and provides a deeper understanding of the ways that gender, adulthood, and identity intersected in premodern Europe.

Living same-name siblings and British historical demography

This article examines the extent to which living siblings were given identical first names. Whilst the practice of sibling name-sharing appeared to have died out in England during the eighteenth century, in northern Scotland it persisted at least until the end of the nineteenth century. Previously it has not been possible to provide quantitative evidence of this phenomenon, but an analysis of the rich census and vital registration data for the Isle of Skye reveals that this practice was widespread, with over a third of eligible families recording same-name siblings. Our results suggest that further research should focus on regional variations in sibling name-sharing and the extent to which this northern pattern occurred in other parts of Britain.

The impact of the HIV/AIDS epidemic on kinship resources for orphans in Zimbabwe

The extended family has been recognized as a major safety net for orphans in sub-Saharan Africa. However, the mortality crisis associated with HIV/AIDS may drastically reduce the availability of relatives and thus undermine traditional forms of mutual support. In this article, the microsimulator SOCSIM is used to estimate and project quantities such as the number of living uncles, aunts, siblings, and grandparents available to orphans. The model is calibrated to the setting of Zimbabwe, using data from demographic and Health Surveys and estimates and projections of demographic rates from the United Nations. The article shows that there is a lag of more than ten years between the peak in orphanhood prevalence and the peak in scarcity of grandparents for orphans. The results indicate that a generalized HIV/AIDS epidemic has a prolonged impact on children and orphans that extends well beyond the peak in mortality. A rapid increase in the number of orphans is followed by a steady reduction in the number of living grandparents for orphans. Consequently, the burden of double orphans (both of whose parents have died) is likely to shift to uncles and aunts. In Zimbabwe, the number of living uncles and aunts per double orphan decreased between 1980 and 2010, but it is expected to increase progressively during the next few decades. Changes in kinship structure have important social consequences that should be taken into account when seeking to address the lack of care for orphans.

Lethal differences: a short history of the concepts of wealth and poverty in Danish epidemiological writings, 1858-1914

Through a study of the history of the concepts of wealth and poverty, this paper investigates the onset of a tradition in the conceptual architecture of epidemiological research concerning social differences in mortality rates from 1858 to 1914. It raises the question as to what the concepts of wealth and poverty meant to those who used them and what objects of interventions the conceptual architecture surrounding the concepts enabled the researchers to create. It argues that a transition began in the late 19th century in which an important framework for the understanding of causal relations behind the mortality patterns changed and that this change in turn influenced the scope of what was conceived as relevant objects of intervention.

Yearning, learning, and conceding: reasons men and women change their childbearing intentions

People's childbearing intentions change over the course of their reproductive lives. These changes have been conceptualized as occurring in response to the realization that an individual is unlikely to achieve his or her intended fertility, because of constraints such as the "biological clock" or lack of a partner. In this article, we find that changes to child-bearing plans are influenced by a much wider range of factors than this. People change their plans in response to the wishes of their partners, in response to social norms, as the result of repartnering, and as the result of learning about the costs and benefits of parenthood; there are also differences between the factors that influence men's and women's decision-making. In a departure from existing studies in this area, we use a flexible analytical framework that enables us to analyze increases in planned fertility separately from decreases. This allows us to uncover several complexities of the decision-making process that would otherwise be hidden, and leads us to conclude that the determinants of increases in planned fertility are not simply equal and opposite to the determinants of decreases.

Marrying in the city in times of rapid urbanization

Economic, social, political, and demographic processes changed Western European cities strongly during the nineteenth century. Especially during this time, the northern part of Belgium (Flanders) became highly urbanized. Investigating the long-term development of the marriage pattern in the cities of Antwerp, Aalst, and Ghent gives a detailed picture of the evolution of the urban marriage pattern. In this article, specific emphasis is on gender, social, and migration distinctions. The results confirm that there is a male-female difference and variation among various social and migrant groups in the age at first marriage during the period 1800-1906. Moreover, regional differences are also visible. In the port city of Antwerp, massive immigration caused a unique evolution in the age at first marriage during the last decades of the nineteenth century, which did not appear in the textile cities of Aalst and Ghent during this time.

The demise of the American Indios

This symposium takes as its point of departure two books by Massimo Livi Bacci, Conquest and El Dorado in the Marshes, published in English in 2008 and 2010. Livi Bacci assesses widely varying estimates of the demographic dimensions of the collapse of the Native populations following their contact with Europeans and elucidates the proximate causes of that catastrophe. Drawing on models that combine production potential with demography, environment, and technology, Shripad Tuljapurkar discusses analogous historical experiences of the populations of Polynesia and the social transformation they entailed. David S. Reher argues that explanations of the estimated demographic dynamics need to take into account the negative fertility responses of the Indigenous population to the disruption of their traditional way of life. Focusing on the biological aspects of immunity to diseases such as smallpox, Andrew Noymer demonstrates that infectious diseases alone could not account for the Indios' population collapse. The contributions to this symposium are based on presentations at a session at the 2010 annual meeting of the Population Association of America, held in Dallas, Texas, that examined the demographic consequences of the Spanish conquest of the Caribbean region and of South America in light of the two books.