Infertility is a major health problem which affects approximately 22% of married couples in reproductive age. The apparent increased incidence of male infertility, in parallel with the widespread use of in vitro fertilization (IVF), raises concern as to the impact of advanced assisted conception techniques in transmitting genetic anomalies to the offspring. Recent research has widely focused on...

Our understanding of parental care behavior can be significantly advanced through the application of Williams's Principle, which states that reproduction has not only a benefit but also a cost to lifetime fitness. My laboratory has formalized Williams's Principle into the relative value theorem and found that its application to fishes, the taxa with the most diverse patterns of parental care, c...

The costs of reproduction are an important constraint that shapes the evolution of life histories, yet our understanding of the proximate mechanism(s) leading to such life-history trade-offs is not well understood. Oxidative stress is a strong candidate measure thought to mediate the costs of reproduction, yet empirical evidence supporting that increased reproductive investment leads to oxidati...

The large human brain, the long period of juvenile dependence, long life span, and male support of reproduction are the co-evolutionary result of the human niche based on skill-intensive techniques of resource accrual. The regulation of fertility under traditional conditions is based upon a co-evolved psychology and physiology where adjustments of investment in offspring depend upon the returns...

Many organisms nourish and care for their offspring, boosting the offspring’s reproductive potential. Trivers (1972) recognized that such parental investment, when made differentially across the sexes, could explain the existence of sexually dimorphic behaviour. However, parental investment in nature is difficult to measure, and explanations involving parental investment are hard to verify. Her...

22 Introduction/Purpose. Exercise improves health but few data are available regarding benefits of 23 exercise in offspring exposed to developmental programming. There is currently a worldwide 24 epidemic of obesity. Obesity in pregnant women predisposes offspring to obesity. Maternal 25 obesity has well documented effects on offspring reproduction. Few studies address ability of 26 offspring e...

Cattle evolved as plain-grazing herbivores gathering together into herds to aid in the defense against predators. In non-domesticated species, matriarchal social groups of mothers and offspring exist separately from groups of male animals in various stages of maturity. The size of the group varies depending on the availability of basic resources such as food supply and access to mates for repro...

Paternal environmental conditions can influence phenotypes in future generations, but it is unclear whether offspring phenotypes represent specific responses to particular aspects of the paternal exposure history, or a generic response to paternal 'quality of life'. Here, we establish a paternal effect model based on nicotine exposure in mice, enabling pharmacological interrogation of the speci...

Analyses of reproductive conflicts of interests have yielded important evolutionary insights in many areas of biology. The usefulness of conflict analyses of traits that have been traditionally interpreted as resulting from female choice is controversial, however. This article explores a possible explanation for why conflicts of interest may be ameliorated in female choice situations. In contra...

The ability to reproduce is the key trait that distinguishes living organisms from inorganic matter, and strategies used achieve successful reproduction are almost as diverse themselves. In animals, most widespread form of involves separate male female sexes: Each sex produces haploid gametes via meiosis, two fuse a new diploid organism. some cases, both parents contribute equally nuclear cytop...