Found 648 Documents across 65 Pages (0.009 seconds)
  1. Periodic catastrophes over human evolutionary history are necessary to explain the forager population paradoxGurven, Michael D. - Proceedings of the National Academy of Sciences of the United States of America, 2019 - 5 Hypotheses

    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.

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  2. Sexually transmitted disease and gender roles: an index of cultural evolutionMackey, Wade C. - Cross-Cultural Research, 2007 - 1 Hypotheses

    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.

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  3. Male contribution to diet and female reproductive successMarlowe, Frank W. - Current Anthropology, 2001 - 3 Hypotheses

    This article seeks to understand male-female bonding by testing the relationship between male contribution to subsistence (a proxy for male provisioning) and female reproductive success in foraging societies. Analysis supports a positive association.

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  4. Testing evolutionary hypotheses about human biological adaptation using cross-cultural comparisonMace, Ruth - Comparative Biochemistry and Physiology. Part A: Molecular and Integrative Physiology, 2003 - 5 Hypotheses

    Can physiological variation in human populations be attributed to environmental variables? Arguing for the importance of phylogenetic comparative methods, the authors present the results of previous research by Holden & Mace (1997) on lactose intolerance as well as introduce new research on sex ratio at birth. The authors suggest that global variance in sex ratio at birth is an adapted response to the physiological costs of giving birth to boys in high fertility populations.

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  5. Men’s status and reproductive success in 33 nonindustrial societies: Effects of subsistence, marriage system, and reproductive strategyvon Rueden, Christopher R. - Proceedings of the National Academy of Sciences, 2016 - 2 Hypotheses

    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.

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  6. Likely Electromagnetic Foundations of Gender InequalityLeón, Federico R. - Cross-Cultural Research, 2022 - 2 Hypotheses

    This study seeks to examine the influence that UV radiation and climate might have on gender inequality, and tests two extant theories on why gender inequality exists -- the life-history theory (aligned with climate) and the cognitive performance theory (aligned with UV radiation). The model with UV radiation as the main predictor fits the data on gender inequality the best, and pathogen prevalence and the ACP1*B allele were also found to be associated with gender inequality. The model was found to be robust across continents and ancestry. The study also highlights the need for further research to better understand the complex interplay of these factors in different cultures.

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  7. Traditional agriculture practices and the sex ratio todayAlesina, Alberto - PLoS ONE, 2018 - 1 Hypotheses

    This study investigates the relationship between historical utilization of the plow and modern sex ratios. The authors argue that in societies without the plow subsistence is generally egalitarian with both men and women contributing. However, the use of the plow requires more physical strength which, they argue, leads to a preference for boys and, thus, men. Therefore, in cultures that use the plow, this is reflected in male-biased sex ratios which are negotiated by way of practices like sex-selective abortions, infanticide, and/or differential access to resources based on sex.

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  8. Sex Ratio at Birth, Polygyny, and Fertility: A Cross-National StudyBarber, Nigel - Social Biology, 2004 - 3 Hypotheses

    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.

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  9. Fertility and mode of subsistence: a phylogenetic analysisSellen, Daniel W. - Current Anthropology, 1997 - 1 Hypotheses

    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.

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  10. On the relationship between country sex ratios and teen pregnancy ratesBarber, Nigel - Cross-Cultural Research, 2000 - 3 Hypotheses

    This study attempted to replicate earlier findings regarding population structure and teen pregnancy rates. Findings support the previous predictions that sex ratio, economic development, and latitude are all inversely related to teen birth rates.

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