71 research outputs found

    Michael C. Crawford and Benjamin C. Campbell (eds.): Causes and Consequences of Human Migration: An Evolutionary Perspective

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98261/1/j.1728-4457.2013.00599.x.pd

    Men, women, and sustainability

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43486/1/11111_2005_Article_BF02208407.pd

    Editor's Introduction: Unforeseen Consequences of Policy Decisions

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43501/1/11111_2004_Article_489373.pd

    Ecological demography: A synthetic focus in evolutionary anthropology

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    The interests of evolutionary anthropologists, behavioral ecologists, and demographers converge on the ecology of human fertility. Ecological conditions influence the optimum pattern of maternal effort. Patterns of abortion, neglect, and infanticide vary with mothers' ability to invest in their children and children's ability to use that investment. As in most other mammals, the ecology of human fertility varies between the sexes: status and resource control are important for males, whereas reproductive value is crucial for females. In pre-industrial societies, and even in monogamous societies in demographic transition, wealthy men had more children than did poorer men. This correlation, often assumed to have disappeared, persists today, with richer men still having more sexual access than others. Sex differences in the ecology of fertility mean that sex of the offspring, as well as birth order, influences parental investment. Because individual fertility varies with environment, it is not surprising that “natural” (uncontrolled) fertility varies across societies or that demographic transitions proceed locally, with occasional reverses, as individuals strive to maximize their lifetime reproductive success in changing, competitive, conditions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38586/1/1360010507_ftp.pd

    Linking our evolutionary past and our ecological future: A behavioral ecological approach

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31869/1/0000819.pd

    Women and sustainable development, a reflection

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43485/1/11111_2005_Article_BF02208406.pd

    The geometry of reaction norms yields insights on classical fitness functions for Great Lakes salmon.

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    Life history theory examines how characteristics of organisms, such as age and size at maturity, may vary through natural selection as evolutionary responses that optimize fitness. Here we ask how predictions of age and size at maturity differ for the three classical fitness functions-intrinsic rate of natural increase r, net reproductive rate R0, and reproductive value Vx-for semelparous species. We show that different choices of fitness functions can lead to very different predictions of species behavior. In one's efforts to understand an organism's behavior and to develop effective conservation and management policies, the choice of fitness function matters. The central ingredient of our approach is the maturation reaction norm (MRN), which describes how optimal age and size at maturation vary with growth rate or mortality rate. We develop a practical geometric construction of MRNs that allows us to include different growth functions (linear growth and nonlinear von Bertalanffy growth in length) and develop two-dimensional MRNs useful for quantifying growth-mortality trade-offs. We relate our approach to Beverton-Holt life history invariants and to the Stearns-Koella categorization of MRNs. We conclude with a detailed discussion of life history parameters for Great Lakes Chinook Salmon and demonstrate that age and size at maturity are consistent with predictions using R0 (but not r or Vx) as the underlying fitness function

    Joint use of habitat by red kangaroos and shorthorn cattle in arid central Australia

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    The distribution of cattle and red kangaroos among the major communities of a 170 km 2 paddock in central Australia was determined from 108 and 82 air surveys respectively over a four and a half year period. Fifty-nine surveys of each species were used in this report. Changes in use of the communities by the two species were analysed in relation to forage conditions using linear regression techniques. The two species showed trends in time of use of the open and wooded communities. Kangaroos used the mulga-perennial community (groved Acacia woodland with a shrub and perennial grass understorey) during good forage conditions and moved to the drought refuge open communities when forage conditions deteriorated. Cattle, on the other hand, used the open communities during good forage conditions and tended to move to the mulga communities and the hills when drought began. Mulga-annual (ungroved Acacia woodland with short grass and forb understorey) was the only major community which showed no clear linear relationship between kangaroo use and forage conditions. This might be a buffer area from which kangaroos come and go as other areas become more attractive as feeding areas. Cattle, however, show some preference for mulga annual during medium forage conditions. There appears to be little spatial interaction by the two species except during drought when kangaroos concentrate on the open communities and some cattle continue to feed in these communities. Community selection seems to be determined mainly by forage conditions, as there is no evidence that one species attracts or repels the other in spatial terms. In the conditions observed, the two species successfully coexisted with some control of numbers of cattle by man.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74942/1/j.1442-9993.1982.tb01301.x.pd

    Intergenerational Wealth Transmission and the Dynamics of Inequality in Small-Scale Societies

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    Small-scale human societies range from foraging bands with a strong egalitarian ethos to more economically stratified agrarian and pastoral societies. We explain this variation in inequality using a dynamic model in which a population’s long-run steady-state level of inequality depends on the extent to which its most important forms of wealth are transmitted within families across generations. We estimate the degree of intergenerational transmission of three different types of wealth (material, embodied, and relational), as well as the extent of wealth inequality in 21 historical and contemporary populations. We show that intergenerational transmission of wealth and wealth inequality are substantial among pastoral and small-scale agricultural societies (on a par with or even exceeding the most unequal modern industrial economies) but are limited among horticultural and foraging peoples (equivalent to the most egalitarian of modern industrial populations). Differences in the technology by which a people derive their livelihood and in the institutions and norms making up the economic system jointly contribute to this pattern
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