Found 1599 Hypotheses across 160 Pages (0.007 seconds)
  1. Current mortality risk will mediate the relationship between early mortality risk and adolescent fertility rates. (4004)Placek, Caitlyn D. - Adolescent fertility and risky environments: a population-level perspective ..., 2012 - 3 Variables

    This study provides the first tests of the relationships between population-level adolescent fertility rates and mortality risk at two different time points. The hypotheses are based in life-history theory, which predicts that human reproductive choices are shaped by mortality. The authors find that reproductive strategies are significantly predicted by both early (between ages 1-7) risks of mortality and current cues of mortality risk.

    Related HypothesesCite
  2. Different levels of early mortality risk will influence the relationship between current risk of death and reproductive outcomes. (4004)Placek, Caitlyn D. - Adolescent fertility and risky environments: a population-level perspective ..., 2012 - 3 Variables

    This study provides the first tests of the relationships between population-level adolescent fertility rates and mortality risk at two different time points. The hypotheses are based in life-history theory, which predicts that human reproductive choices are shaped by mortality. The authors find that reproductive strategies are significantly predicted by both early (between ages 1-7) risks of mortality and current cues of mortality risk.

    Related HypothesesCite
  3. Combining more than one of the four demographic scenarios (altered mean vital rates (i.e., fertility and mortality), vital rate stochasticity, vital rate covariance, and periodic catastrophes) increases the likelihood of returning the rate of population growth to ZPG p. 12763.Gurven, Michael D. - Periodic catastrophes over human evolutionary history are necessary to expla..., 2019 - 5 Variables

    Researchers looked at four different demographic scenarios (altered mean vital rates (i.e., fertility and mortality), vital rate stochasticity, vital rate covariance, and periodic catastrophes) and their possible effects on the rapid population growth of contemporary human foragers and steady population decline of chimpanzees. They evaluated these variables and the various conditions that would favor a more sustainable zero population growth (ZPG) among 10 small-scale subsistence human populations (Agta, Ache, Hadza, Hiwi, Ju/’hoansi, Gainj, Tsimane, Yanomamo, Northern Territory Aborigines, and Herero) and five wild chimpanzee groups (Gombe, Kanyawara, Mahale, Ngogo, and Taï). The results state that the most effective modifications towards ZPG would include a combination of more than one of the four demographic scenarios tested, with the most realistic solution including both vital rate alteration and an increase in catastrophes.

    Related HypothesesCite
  4. Rates of women's infection with HIV/AIDS will be positively associated with income, infant mortality, percentage of labor force engaged in agriculture, total fertility rate, and negatively associated with murder/homicide rate (54).Mackey, Wade C. - Sexually transmitted disease and gender roles: an index of cultural evolution, 2007 - 6 Variables

    This article examines the relationship between HIV/AIDS and several parameters of a nation’s demography, including income, mortality, labor, fertility, and homicide rates. Associations were supported by statistical tests. Regional differences are considered; Europe and the Muslim area had lower level of women’s HIV/AIDS infection. Four cultural adaptations to combat STDs are discussed.

    Related HypothesesCite
  5. The secondary sex ratio will decline as total fertility increases.Barber, Nigel - Sex Ratio at Birth, Polygyny, and Fertility: A Cross-National Study, 2004 - 2 Variables

    This article discusses the variation in sex ratios at birth among human populations and the possible explanations for this variation. One possible explanation is the timing of intercourse and its relationship to the frequency of intercourse, which can affect the timing of conception. The article presents evidence that the male/female sex ratios of 148 countries declined with total fertility rates and polygyny intensity and increased with contraception use in correlational analysis. These results were independent of mother's age and level of economic development. The predictive effect of polygyny and contraception disappeared when total fertility was added to the equation. The article also considers other possible explanations for the variation in sex ratios, such as genetics, hormones, nutrition, and social factors.

    Related HypothesesCite
  6. A culturally independent association exists between dependence on agriculture and fertility(879).Sellen, Daniel W. - Fertility and mode of subsistence: a phylogenetic analysis, 1997 - 2 Variables

    This study tests for a relationship between subsistence type and fertility using phylogenetic and statistical analyses. The authors find a clear relationship between dependence on agriculture and fertility among non-permanently settled groups.

    Related HypothesesCite
  7. Through altering mean vital rates (both fertility and mortality) it would be possible to adjust the current rapid growth of contemporary human forager groups to achieve ZPG (zero population growth) p. 12761. Gurven, Michael D. - Periodic catastrophes over human evolutionary history are necessary to expla..., 2019 - 2 Variables

    Researchers looked at four different demographic scenarios (altered mean vital rates (i.e., fertility and mortality), vital rate stochasticity, vital rate covariance, and periodic catastrophes) and their possible effects on the rapid population growth of contemporary human foragers and steady population decline of chimpanzees. They evaluated these variables and the various conditions that would favor a more sustainable zero population growth (ZPG) among 10 small-scale subsistence human populations (Agta, Ache, Hadza, Hiwi, Ju/’hoansi, Gainj, Tsimane, Yanomamo, Northern Territory Aborigines, and Herero) and five wild chimpanzee groups (Gombe, Kanyawara, Mahale, Ngogo, and Taï). The results state that the most effective modifications towards ZPG would include a combination of more than one of the four demographic scenarios tested, with the most realistic solution including both vital rate alteration and an increase in catastrophes.

    Related HypothesesCite
  8. The presence of grandmothers will predict lower child mortality rates (10).Sear, Rebecca - Who keeps children alive? A review of the effects of kin on child survival, 2008 - 2 Variables

    Evolutionary anthropologists have long emphasized the puzzle of short inter-birth intervals, extended childhoods, and long post-reproductive lives of humans, in particular the problem it poses for raising children. While there is agreement that mothers receive assistance from kin to offset the high costs of raising children, opinion is equivocal as to which kin help and to what extent they help. Here the authors review 45 studies from historical and contemporary natural fertility populations to assess the effects of various types of kin on child survival rates.

    Related HypothesesCite
  9. Male status is positively associated with mating effort, but not with offspring mortality (10825).von Rueden, Christopher R. - Men’s status and reproductive success in 33 nonindustrial societies: Effects..., 2016 - 8 Variables

    The researchers examine associations between male status and various measures of reproductive success among foraging/non-foraging, and monogamous/polygynous societies in order to test the "egalitarian hypothesis" which predicts lower status effects in hunter-gatherer groups. Contrary to this hypothesis, they find that male social status is equally significantly associated with reproductive success in foraging and nonforaging societies. Additional support is found for the "mating effort" hypothesis, which predicts that male reproductive success will be more associated with fertility than offspring mortality in polygynous societies, leading the authors to make various suggestions regarding the evolutionary mechanisms at play.

    Related HypothesesCite
  10. Through altering a population’s vital rate stochasticity it would be possible to adjust the current rapid growth of contemporary human forager groups to achieve ZPG (zero population growth) p. 12763.Gurven, Michael D. - Periodic catastrophes over human evolutionary history are necessary to expla..., 2019 - 2 Variables

    Researchers looked at four different demographic scenarios (altered mean vital rates (i.e., fertility and mortality), vital rate stochasticity, vital rate covariance, and periodic catastrophes) and their possible effects on the rapid population growth of contemporary human foragers and steady population decline of chimpanzees. They evaluated these variables and the various conditions that would favor a more sustainable zero population growth (ZPG) among 10 small-scale subsistence human populations (Agta, Ache, Hadza, Hiwi, Ju/’hoansi, Gainj, Tsimane, Yanomamo, Northern Territory Aborigines, and Herero) and five wild chimpanzee groups (Gombe, Kanyawara, Mahale, Ngogo, and Taï). The results state that the most effective modifications towards ZPG would include a combination of more than one of the four demographic scenarios tested, with the most realistic solution including both vital rate alteration and an increase in catastrophes.

    Related HypothesesCite