منابع مشابه
Distorting sex ratios.
D uring sperm production in mammals, the process of meiosis generates sper-matozoa that are genetically different but functionally equivalent. So, with respect to the sex chromosomes, for example, equal numbers of sperm are produced carrying either an X or a Y chromosome. Because X and Y sperm are equally capable of fertilizing an egg, equal numbers of male and female embryos are produced, and ...
متن کاملColony sex ratios in the facultatively polygynous ant Pheidole pallidula: a reanalysis with new data.
A recent study by Fournier et al. (2003) provides important new information on sex allocation in the ant Pheidole pallidula, and proposes a new scenario for sex-ratio evolution in P. pallidula and similar species. However, Helms proposed to the authors that two important conclusions of the study were questionable because of potential problems with the analyses. Here we provide new data and a re...
متن کاملBayesian analysis of split sex ratios: methods and application to the ant Aphaenogaster rudis
Objective: We develop the use of Bayesian logistic regression models for the analysis of sex ratio data for organisms with variable brood sizes. Background: Ant populations often exhibit ‘split sex ratios’, whereby most colonies produce strongly male-biased or female-biased broods. Furthermore, colony-level sex ratios may depend on brood size or other non-normally distributed covariates. The la...
متن کاملColony sex ratios vary with queen number but not relatedness asymmetry in the ant Formica exsecta.
Split-sex-ratio theory assumes that conflict over whether to produce predominately males or female reproductives (gynes) is won by the workers in haplodiploid insect societies and the outcome is determined by colony kin structure. Tests of the theory have the potential to provide support for kin-selection theory and evidence of social conflict. We use natural variation in kinship among polygyno...
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ژورنال
عنوان ژورنال: Nature
سال: 1994
ISSN: 0028-0836,1476-4687
DOI: 10.1038/370257a0