Wing size, sex-comb tooth number and larval competitive ability had only weak statistical differences. The significant difference came in adult survivability. This result supports the proposition that females with a choice of mates are able to select males whose genetic makeup gives their offspring a chance for a longer lifespan. The choice may even account for an increase in body size. The success of this research may lie in the fact that selection was carried out over multiple generations, which increased the likelihood of identifying small genetic effects.
Some problems remain, however.
Still, the findings confirm that adult survival rates increased with an increased opportunity for sexual selection, a result consistent with the idea that females choose males on the basis of relatively high genetic quality. The research opens some new doors for investigation. Promislow says that not all fitness traits will necessarily benefit from sexual selection and that gene-environment interactions could result in unexpected consequences generations later. Genetic benefits to one sex might even prove detrimental to the other. In the meantime, the current study confirms the validity of at least one model of sexual selection.