Phylogenetic and population genetic methods that compare nucleic acid variation are being used to identify species and populations of pathogenic fungi and determine how they reproduce in nature. These studies show that asexual or sexual reproductive morphology does not necessarily correlate with clonal or recombining reproductive behavior, and that fungi with all types of reproductive morpholog...

Genetic and cell biological analyses of sperm behavior in the female reproductive tract are providing important clues to the mechanisms of sperm competition, a form of sexual selection that is an important force that shapes reproductive behavior, physiology and morphology in a wide range of species.

BACKGROUND Climate-driven environmental change in the North Pacific has been well documented, with marked effects on the habitat and foraging behavior of marine predators. However, the mechanistic linkages connecting climate-driven changes in behavior to predator populations are not well understood. We evaluated the effects of climate-driven environmental variability on the reproductive success...

Exposure to estrogenic endocrine disruptors (EDCs) during development affects fertility, reproductive and non-reproductive behavior in mammals and fish. These effects can also be transferred to coming generations. In fish, the effects of developmental EDC exposure on non-reproductive behavior are less well studied. Here, we analyze the effects of 17α-ethinylestradiol (EE2) on anxiety, shoaling ...

The research that has been conducted to date on Vietnamese adolescents has focused on unprotected and unsanctioned sexual activity and its health consequences, specifically abortion and sexually transmitted diseases, especially HIV. The question we pose in this article is whether this concern is warranted. Is the population community justified in limiting research on this population to early se...

A competing theory of teen reproductive behavior argues that teens give little consideration to the costs of an unwanted pregnancy when deciding to have sex. Under this model, changes in laws that alter the price of accessing reproductive health services have little effect on sexual activity. It is only after an act of unprotected intercourse or contraceptive failure—when faced with an unwanted...

Five characters separate man from other hominoids-a large neocortex, bipedality, reduced anterior dentition with molar dominance, material culture, and unique sexual and reproductive behavior. Evidence provided by the fossil record, primate behavior, and demographic analysis shows that the traditional view that early human evolution was a direct consequence of brain expansion and material cultu...

Reinforcement is an increase in premating reproductive isolation between taxa resulting from selection against hybrids. We present a model of reinforcement with a novel type of selection on female mating behavior. Previous models of reinforcement have focused on the divergence of female mating preferences between nascent species. We suggest that an increase in the level of female mating discrim...

This study aims at investigating the effectiveness of nutritional supplements containing vitamins, minerals, and ammonia on the sexual and breeding behaviors in Ghezel sheep. To this end, 28 three and half-year old ewes (50±3 kilograms) with the record of giving birth to two lambs and 4 three-year old (90±3.5 kilograms) rams were used. The ewes were divided into two groups of A (i.e., treatment...

Gonads are the main source of sex steroids, which have been implicated in the regulation of sexually differentiated behavior, such as reproductive and aggressive displays. In the Mozambique tilapia (Oreochromis mossambicus) territorial males have higher androgen levels than non-territorials, express reproductive behavior and use a urine-borne pheromone to signal their social status towards cons...