The young sperm gambit

Thermodynamic and oxidative damage to the condensed nuclear DNA of spermato zoa may result in age-related deterioration that results in zygote death. B y definition, any such spermatozoan-age effects are direct (i.e. nonheritab le) and, if they occur, females may be selected to avoid such costs. This p aper examines the potential of spermatozoan-age effects to provide alternat ive explanations for several reproductive phenomena.