Recent studies have uncovered remarkable variation in paternity within primate groups. To date, however, we lack a general understanding of the factors that drive variation in paternity skew among primate groups and across species. Our study focused on hypotheses from reproductive skew theory involving limited control and the use of paternity "concessions" by investigating how paternity covarie...

This study sought to assess the potential effects of hand-rearing by evaluating the relationships among rearing type and reproductive success in the American Zoo and Aquarium Association’s Species Survival Plan for western lowland gorillas. Our study included data on 697 gorillas: 257 wild-born (WB) and 440 born at zoos or related facilities in North America. We found no significant differences...

Organisms are selected to maximize lifetime reproductive success by balancing the costs of current reproduction with costs to future survival and fecundity. Males and females typically face different reproductive costs, which makes comparisons of their reproductive strategies difficult. Burying beetles provide a unique system that allows us to compare the costs of reproduction between the sexes...

Two experiments were conducted to determine whether prostaglandin F2~ (PGF2a) administered to does immediately before natural or artificial insemination would increase the retention of sperm in the reproductive tract. The PGF2~ was injected intramuscularly at 200 /~g/kg of body weight. In the first experiment, 16 estrous does, eight injected intramuscularly with PG2a, were mated naturally and n...

Background The effect of smoking cigarettes is followed by diverse effects on ovaries and developing follicles but the effect of passive smoking on ovarian function is unknown. On the other hand, the ovarian response to induction is a very important step in assisted reproduction. The aim of this study is to compare ovarian response in passive smokers and non-passive smokers in an assisted repro...

Bateman's experimental study of Drosophila melanogaster produced conclusions that are now part of the bedrock premises of modern sexual selection. Today it is the most cited experimental study in sexual selection, and famous as the first experimental demonstration of sex differences in the relationship between number of mates and relative reproductive success. We repeated the experimental metho...

Objective: To assess perception and behavior after reproductive health counseling among adolescent patients in a tertiary care-based pediatric rheumatology clinic. Methods: Adolescent females seen at Stanford pediatric rheumatology clinic were prospectively enrolled during routine visits. At study start, standard clinic procedures for the following were reviewed with providers: 1) HEADSS (home,...

Background & aim: Considering the lack of information regarding the effects of religion on young couples’ fertility preferences, this study aimed to evaluate the relationship between religious beliefs and fertility preferences among engaged couples in Mashhad, Iran, in 2013. Methods:This cross-sectional study was conducted on 450 engaged couples, referring to premarital counseling clinics at h...