Ongoing evolution of polyandry, and consequent extra-pair reproduction in socially monogamous systems, is hypothesized to be facilitated by indirect selection stemming from cross-sex genetic covariances with components of male fitness. Specifically, polyandry is hypothesized to create positive genetic covariance with male paternity success due to inevitable assortative reproduction, driving ong...

Background: Cigarette smoke contains many oxidants and may alter the human reproduction by inducing oxidative stress (OS) in both active and passive smokers. This study was designed to evaluation the effect of environment tobacco smoke (ETS) exposure on oxidative stress in follicular follicle and assisted reproduction outcomes. Materials and Methods: A prospective study was carried out on 236 i...

BACKGROUND AND AIMS The knotweed complex, Fallopia spp. (Polygonaceae), belongs to the most troublesome invasive species in Europe and North America. Vegetative regeneration is widely recognized as the main mode of reproduction in the adventive regions. However, the contribution of sexual reproduction to the success of these invasive species has only been detailed for the British Isles. An exam...

Current industry estimates of reproductive performance for cattle, sheep, and swine operations indicate that males contribute significantly to fertility failures. This appears to be due to the use of subfertile individuals and emphasizes the need for additional research in identifying characteristics of sperm that compromise fertilization. In theory, sperm characteristics, such as motility or t...

the pollution of aquatic ecosystems may affect natural reproduction of fish populations by decreasing the fertilization efficiency. among the various sources of pollution, heavy metals are important group, being found in both freshwater and marine environment. the present study investigated changes of sperm characteristics of caspimyzon wagneri when exposed to manganese (mn). spermatozoids were...