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1.
Our objective is to test an optimality model of human fertility that specifies the behavioral requirements for fitness maximization in order (a) to determine whether current behavior does maximize fitness and, if not, (b) to use the specific nature of the behavioral deviations from fitness maximization towards the development of models of evolved proximate mechanisms that may have maximized fitness in the past but lead to deviations under present conditions. To test the model we use data from a representative sample of 7,107 men living in Albuquerque, New Mexico, between 1990 and 1993. The model we test proposes that low fertility in modern settings maximizes number of grandchildren as a result of a trade-off between parental fertility and next generation fertility. Results do not show the optimization, although the data do reveal a trade-off between parental fertility and offspring education and income. We propose that two characteristics of modern economies have led to a period of sustained fertility reduction and to a corresponding lack of association between income and fertility. The first is the direct link between costs of investment and wage rates due to the forces of supply and demand for labor in competitive economies. The second is the increasing emphasis on cumulative knowledge, skills, and technologies in the production of resources. Together they produce historically novel conditions. These two features of modern economies may interact with evolved psychological and physiological mechanisms governing fertility and parental investment to produce behavior that maximizes the economic productivity of lineages at the expense of fitness. If cognitive processes evolved to track diminishing returns to parental investment and if physiological processes evolved to regulate fertility in response to nutritional state and patterns of breast feeding, we might expect non-adaptive responses when returns from parental investment do not diminish until extremely high levels are reached. With high economic payoffs from parental investment, people have begun to exercise cognitive regulation of fertility through contraception and family planning practices. Those cognitive processes maynot have evolved to handle fitness trade-offs between fertility and parental investment. A preliminary presentation of this data was published in R. I. M. Dunbar, ed.,Human Reproduction Decisions: Biological and Social Perspectives. New York: St. Martin’s Press, 1995. Support for the research project, “Male Fertility and Parenting in New Mexico,” began with two seed grants from the University of New Mexico’s Biomedical Research Grants Program, 1988 and 1989, and one from the University of New Mexico Research Allocations Committee, 1988. Further seed money as well as interim funding came from the William T. Grant Foundation (#89130589 and #91130501). The major support for the project came from the National Science Foundation from 1990 to 1993 (#BNS-9011723 and #DBS-911552). Both National Science Foundation grants included Research Experience for Undergraduates supplements. Hillard S. Kaplan is an Associate Professor of Anthropology at the University of New Mexico. His earlier research and publications focused on food sharing, time allocation, parental investment, and reproductive strategies among Ache hunter-gatherers in Paraguay, Machiguenga and Piro forager-horticulturalists in Peru, and villagers of several ethnicities in Botswana. New research and theory concern fertility, parental investment, and mating strategies in developed and developing nations. This research formulates a new theory of reproductive decision-making and the demographic transition, integrating human capital and parental investment theory in a synthesis of economic and evolutionary approaches. Jane B. Lancaster is a Professor of Anthropology at the University of New Mexico. Her research and publications are on human reproductive biology and behavior, especially human parental investment; women’s reproductive biology of pregnancy, lactation, and child-spacing; and male fertility and investment in children. Current research with Hillard S. Kaplan is on male life history strategies among a large sample of men in New Mexico. She has coedited three books on human parental investment:School-Age Pregnancy and Parenthood (with B. Hamburg),Parenting across the Life Span (with J. Altmann, A. Rossi, and L. Sherrod), andOffspring Abuse and Neglect (with R. Gelles). She is scientific editor of a quarterly journal,Human Nature: An Interdisciplinary, Biosocial Perspective published by Aldine de Gruyter. She is also a council member of the newly formed Human Behavior and Evolution Society. John A. Bock is Andrew W. Mellon Post-Doctoral Fellow in Epidemiology and Population Health at the National Centre for Epidemiology and Population Health, The Australian National University. His research focuses on the allocation of parental investment and the determinants of children’s activities, integrating aspects of economic and evolutionary theory. He has ongoing field research with Bantu and Bushmen agro-pastoralists and forager-horticulturalists in the Okavango Delta, Botswana. He is also collaborating with Lancaster and Kaplan on the determinants of progeny distribution and homosexuality among New Mexican men. Sara E. Johnson is a Ph.D. candidate at the University of New Mexico. Her major research trajectory focuses on trade-offs in life history characters. Her research experience includes participation in a study of variation in growth and development among children in a multi-ethnic community in the Okavango Delta, Botswana, in addition to her dissertation work on individual variation in growth and mortality among juvenile baboons. She is collaborating with Lancaster and Kaplan on the association between survival and fertility among Albuquerque men.  相似文献   
2.
The main characteristics of the dominant economic system, including the increasing use of markets and money are described. The global system has expanded trade, including international trade, and production tremendously. While this system has the potential to favour nature conservation, in practice the opposite has occurred. Difficulties raised for conservation of biodiversity by short-term economic crises such as deficits in a country's international payments, the adoption of policies for structural economic adjustment, international capital flows, international loans and foreign aid as well as debt-for-nature swaps are discussed. As explained, it is politically difficult in market economies to support nature conservation at the expense of economic growth and as more economies develop and become market economies this problem spreads. Given global interdependence of nations, an important issue is the distribution of net benefits from biodiversity conservation between developed and less developed countries. Possible distributions of benefits and related issues are discussed. In conclusion, the importance of political lobbying by nature conservation groups in developed market economies is emphasised as a means of ensuring correction of market failures. Unfortunately, no economic system is likely to prove satisfactory in itself in conserving biodiversity so political action by conservationists is always required.  相似文献   
3.
Abstract

According to advances in phytogeographic knowledge, a revision of boundaries for the Italian Ecoregions have been made. Main changes relate to the southern and eastern limits between Temperate and Mediterranean Divisions. The revision triggered a comprehensive update of Ecoregions for an improved support to biodiversity and sustainable management initiatives.  相似文献   
4.
Using longitudinal data, this paper analyses the effect of different forms of social capital on the likelihood of employment and the occupational status of first generation immigrant men in Germany. This allows me to examine to what extent social capital of the bonding and the bridging types yield different returns. The study considers how contacts with natives, co-ethnic ties and family-based social capital are beneficial to the economic position of immigrant men. Random effects and fixed effects models show that strong inter-ethnic ties are beneficial both for employment and occupational status. There is no effect of co-ethnic ties and family-based social capital. It is concluded that, when using panel data, bridging social capital contributes to a better economic position and bonding social capital does not.  相似文献   
5.
Social capital takes on distinctive meaning in the context of large-scale immigration from poor to rich countries. In this article, characteristics of social capital embedded in transnational networks and norms, conditions conducive to the formation of such networks, and effects such networks have are extrapolated from an analysis of how and why cross-border relations among Cuban-Americans and Cubans in their homeland have changed since the 1959 Castro-led revolution. The transnational social capital generating benefit on which the study focuses is remittances. Remittances are of growing global importance to less developed countries, and in some countries they generate more revenue than foreign aid and foreign investment. The analysis addresses a range of unintended as well as intended consequences remittances may have.  相似文献   
6.
As interest in ethnics and their entrepreneurial activities has grown in recent years, sociologists have come to emphasize the importance of ethnic social structures as the source of actions propelling business growth. In a sign of convergence with the ‘new economic sociology’, recent literature suggests that embeddedness in ethnic networks and communities leads to cooperative, if not conformist, behaviour among ethnic economic actors. This article looks at the ‘other side’ of embeddedness, through a case‐study of African‐American, Caribbean, Korean and white construction contractors in New York City. I argue that, in construction, the embeddedness of economic behaviour in ongoing social relations among a myriad of social actors impedes access to outsiders. Embeddedness contributes to the liabilities of newness that all neophytes encounter, breeding a preference for established players with track records. However, the convergence of economic and ethnic ties has a further baneful effect, since outsiders also fall outside those networks that define the industrial community. While African‐American, Caribbean and Korean outsiders all experience these barriers in similar ways, they differ in the adaptive strategies that they have pursued. African Americans appear to be most disadvantaged, in part because they have been the most exposed to the social closure that results from the mobilization of white ethnics’ social capital. By contrast, Caribbeans and Koreans entered the labour market in societies where racial domination played little or no role in labour market outcomes ‐ a considerable asset since construction skills are transferable from one society to another. The Koreans appear to be the most embedded in ethnic networks, through which they secure jobs and skilled labour, though class factors play a role here as well and even the Koreans must reach out beyond the ethnic community for a clientele. By contrast, ethnic solidarity operates less powerfully among the black contractors, who are tied to a community where intra‐ethnic diversity and internal competition have grown as a result of immigration. In the absence of an ethnic market, black'entrepreneurs turn to the state, whose requirements and dependence on union labour expose black builders to risks from which their Korean counterparts are sheltered.  相似文献   
7.
The role of ethnic resources in the educational success of immigrants is highly disputed. Combining arguments of segmented assimilation and Coleman's concept of family social capital, this study investigates whether speaking one's language of origin at home relates to achievement by facilitating the mobilization of resources or their transmission from parents to children. Mediating and moderating mechanisms are disentangled and empirically questioned in regression models that predict the mathematical competences of immigrant students from Turkey, Poland and the former Soviet Union. Based on data from the German National Educational Panel Study, the results contradict the assumption that foreign language use will contribute to education through mechanisms of social capital. Regardless of parental human capital or the group of origin, the language used at home does not affect the students’ learning when German language proficiency is accounted for.  相似文献   
8.
ABSTRACT

This paper examines how race, class, and gender intersect to shape professional Latinos’ entrepreneurial incorporation, as observed by the conditions that prompt professional Latinos to start a business, including access to capital and experiences with discrimination. In-depth interviews with professional Latino business owners in Los Angeles reveal that individual human capital – via resources and wealth accrued through corporate careers – facilitates entrepreneurial activity. Race, ethnicity, and gender, as intersectional social group identities, combine with class to shape variegated impacts on access to capital and business experiences by gender and target market. Ethnicity is a resource for those serving the coethnic community and is more significant in shaping business ownership experiences for men who target a racially/ethnically diverse clientele, whereas gender and race are more salient for women outside the coethnic community. This study contributes to the ethnic enterprise literature by going beyond ethnicity to demonstrate that multiple dimensions of identity shape professional Latino/as’ entrepreneurial incorporation.  相似文献   
9.
Both physiologically and ecologically based explanations have been proposed to account for among‐species differences in lifespan, but they remain poorly tested. Phylogenetically explicit comparative analyses are still scarce and those that exist are biased towards homoeothermic vertebrates. Insect studies can significantly contribute as lifespan can feasibly be measured in a high number of species, and the selective forces that have shaped it may differ largely between species and from those acting on larger animals. We recorded adult lifespan in 98 species of geometrid moths. Phylogenetic comparative analyses were applied to study variation in species‐specific values of lifespan and to reveal its ecological and life‐history correlates. Among‐species and between‐gender differences in lifespan were found to be notably limited; there was also no evidence of phylogenetic signal in this trait. Larger moth species were found to live longer, with this result supporting a physiological rather than ecological explanation of this relationship. Species‐specific lifespan values could not be explained by traits such as reproductive season and larval diet breadth, strengthening the evidence for the dominance of physiological determinants of longevity over ecological ones.  相似文献   
10.
Each year businesses, governments, and homeowners in the United States invest around one fifth of gross domestic product into the creation of capital assets such as buildings, machinery, and software to enable production and consumption. Use of capital is typically included to some extent in environmental life cycle assessments of goods and services but is not incorporated into most environmentally extended input‐output (EEIO) models, including the US Environmental Protection Agency's USEEIO. Capital assets are typically created in years prior to their use, so a challenge lies in distributing the impacts of their creation over time. In this work, a highly detailed capital flow matrix approach is followed to distribute the use of fixed capital assets to consuming industries. Data from the US Bureau of Economic Analysis's Fixed Asset Accounts is merged with its Industry Accounts data by the creation of concordance tables. Public highways and streets are partially reallocated to industries operating vehicles. The resulting capital use matrix is later combined into a modified USEEIO. “Housing” is found to be the largest consumer of fixed assets, followed by general government, fossil fuel extraction, and financial industries involved in leasing. Construction, vehicles, and machinery are mostly used by industries in the form of fixed assets. The types of fixed assets used by industries are consistent with expectations: housing is dominated by structures, transport by equipment, and information industries by intellectual property products.  相似文献   
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