Sperm competition risk and intensity can select for adaptations that increase male fertilisation success. Evolutionary responses are examined typically by generating increased strength of sexual selection via direct manipulation of female mating rates (by enforcing monandry or polyandry) or by alteration of adult sex ratios. Despite being a model species for sexual selection research, the effec...

Strongly female-biased sex ratios are typical for the fungalfeeding haplodiploid Xyleborini (Scolytinae, Coleoptera), and are a result of inbreeding and local mate competition (LMC). These ambrosia beetles are hardly ever found outside of trees, and thus male frequency and behavior have not been addressed in any empirical studies to date. In fact, for most species the males remain undescribed. ...

the aim of this study was identification of important factors and their effects on mortality of lori-bakhtiari lambs from birth to weaning. the data set used for statistical analysis were collected from 4991 lambs born between 1370 and 1384 in flock at lori-bakhtiari sheep breeding station. data was modeled using logistic regression. mortality variable as dependent and ewe weight at mating, ewe...

Theoretical and empirical research on the evolution of clutch size has proved to be an extremely productive area of evolutionary biology. A general prediction is that individuals should produce a smaller number of offspring when resources are more limited, such as when multiple individuals compete for the same resources for their development. However, we expect that the opposite prediction aris...

BACKGROUND AND AIMS Evolutionary transitions between separate and combined sexes have frequently occurred across various plant lineages. In mosses, which are haploid-dominant, evolutionary transitions from separate to combined sexes are often associated with genome doubling. Polyploidy and hermaphroditism have strong effects on the inbreeding depression of a population, and are subsequently pre...

Combination of the sterile insect technique with the incompatible insect technique is considered to be a safe approach to control Aedes albopictus populations in the absence of an accurate and scalable sex separation system or genetic sexing strain. Our previous study has shown that the triple Wolbachia-infected Ae. albopictus strain (wAlbA, wAlbB and wPip) was suitable for mass rearing and fem...

Sex ratio theory predicts that, under local mate competition, a more female-biased offspring sex will be produced by females when their relatedness to mates is closer. We assess how the sexual composition of broods responds mother–mate using Goniozus legneri Gordh (Hymenoptera: Bethylidae), parasitoid wasp that has biased ratios due competition. Relatedness was varied providing virgin with eith...

Although support for same-sex marriage has grown dramatically over the past decade, public opinion remains markedly divided. Here, we propose that the political divide over same-sex marriage represents a deeper divide between conflicting mating strategies. Specifically, we propose that opposition to same-sex marriage can be explained in terms of (a) individual differences in short-term mating o...