Sex ratios in primate groups
نویسندگان
چکیده
منابع مشابه
Maternal rank and local resource competition do not predict birth sex ratios in wild baboons.
We test two models of adaptive adjustment of birth sex ratios that are expected to apply to Cercopithecine primate species. It has been predicted that when maternal investment differentially influences the reproductive success of male and female offspring, females in good condition will bias investment in favour of the sex that gains the greatest fitness returns from additional investment. This...
متن کاملReconsidering the null hypothesis: Is maternal rank associated with birth sex ratios in primate groups?
Trivers and Willard hypothesized that vertebrates adaptively vary the sex ratio of their offspring in response to the mother's physical condition [Trivers, R. L. & Willard, D. (1973) Science 179, 90-92]. This hypothesis has produced considerable debate within evolutionary biology. Here we use meta-analysis techniques to evaluate claims that nonhuman primate females facultatively adjust the sex ...
متن کاملLocal resource competition and local resource enhancement shape primate birth sex ratios.
Sex ratio theory provides a powerful source of testable predictions about sex allocation strategies. Although studies of invertebrates generally support predictions derived from the sex ratio theory, evidence for adaptive sex ratio biasing in vertebrates remains contentious. This may be due to the fact that most studies of vertebrates have focused on facultative adjustment in relation to matern...
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Present paper is a report on the ratios in different age group of Iranians. In this investigation unlike the former reports, insteed of sampling, we considered the total Iranian population. We calculated the secondary sex ratios in Iranians according to their residential conditions (urbans, rurals and nomads) and age group. Age group in this study were arranged in 5 year periods , and p...
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Effects of mating sex ratios on production performance in Indian peafowl were investigated at PunjabWildlife Research Institute, Gatwala Faisalabad. Research was conducted from May through August 2007 toexplore the most productive mating sex ratio. The sex ratios have a significant effect on egg production.Maximum mean eggs (1.63) were produced by the sex ratio 1:2 while maximum egg fertility (...
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