The hypothesis that maternal effects act as an adaptive bridge in translating maternal environments into offspring phenotypes, and thereby affecting population dynamics has not been studied in the well-controlled fields. In this study, the effects of maternal population density on offspring stress axis, reproduction and population dynamics were studied in root voles (Microtus oeconomus). Parent...

The gender of the offspring is determined by the fertilizing sperm. Previous gender studies were based on washed sperm, but not on sperm in seminal plasma. The objective was to correlate motility parameters assessed during semen analyses with the offspring gender. For comparison, fixed sperm head DNA quantitated by Hoechst 33342 fluorescence microscopy was also analyzed. Forty-six patients unde...

The possession of offspring is the most important human biological goal, which conditions the survival of the human species. The problem of the lack of offspring is a phenomenon concerning approximately 15% of married couples in Poland. In a half of the cases, the causative agent is the male factor infertility problem. It is considered that in approximately 20% of patients with idiopathic infer...

Testosterone (T) is often referred to as the "male hormone," but it can influence aggression, parental behavior, and immune function in both males and females. By experimentally relating hormone-induced changes in phenotype to fitness, it is possible to ask whether existing phenotypes perform better or worse than alternative phenotypes, and hence to predict how selection might act on a novel or...

Eusocial animal societies are typified by the presence of a helper (worker) caste which predominantly cares for young offspring in a social group while investing little in their own direct reproduction. A key question is what determines whether an individual becomes a worker or leaves to initiate her own reproduction. In some insects, caste is determined nutritionally during development. In oth...

Natural selection favors alleles that increase the number of offspring produced by their carriers. But in a world that is inherently uncertain within generations, selection also favors alleles that reduce the variance in the number of offspring produced. If previous studies have established this principle, they have largely ignored fundamental aspects of sexual reproduction and therefore how se...

To discuss the psychological impact of disclosure decisions on donor gamete participants including gamete donors, intended parents, and the children conceived through these third party reproductive techniques. In the past decade, there has been a dramatic increase worldwide in the number of children born as a result of gamete donation. The growing demand for these programs has resulted in a tre...

Age at reproduction can influence the survival and future of an individual as well that their offspring. Remarkably, it has been shown grandmaternal age also affect characteristics grandoffspring in humans laboratory or semi-captive animals. However, currently we do not know whether effects exist wild populations. We gathered data on female reproduction, offspring using a 16-year long-term surv...

introduction: there are several evidences that show various environmental stresses during pregnancy, affect physiological behavior of the offspring. in this study the effects of rem (rapid eye movement) sleep deprivation of pregnant rats on spatial learning of adult male offspring by morris water maze were investigated. methods: water tank technique was used for inducing rem sleep deprivation. ...

Avoiding inbreeding, and therefore avoiding inbreeding depression in offspring fitness, is widely assumed to be adaptive in systems with biparental reproduction. However, inbreeding can also confer an inclusive fitness benefit stemming from increased relatedness between parents and inbred offspring. Whether or not inbreeding or avoiding inbreeding is adaptive therefore depends on a balance betw...