In this section, I argue that keeping the difference constant between utility derived from the amount of marital interaction in monogamous mating and in polygynous mating is harmless.
Interaction analyses showed that having a current partner who was circumcised had a significant protective effect against cervical HPV infection in women reporting two or more lifetime sexual partners but not in monogamous women (P for interaction = 0.005) (Table 3).
Second, we used treatment-level (Y chromosome and mitochondrial genotyping) reproductive success measures to determine differences between promiscuous line and monogamous line mice that achieved social dominance (that is, the interaction between social dominance and reproductive success).
If she is involved in polygyny, she enjoys less utility due to a lower amount of marital interaction compared to what she would enjoy in a monogamous marriage.
This, in turn, should help explain complex social interactions seen in both rodents and people.In some cases the monogamous rodents will, no doubt, become promiscuous.
A man who marries polygynously provides less marital interaction to each of his wives compared to a man in a monogamous marriage.
Thus, the risk of infection almost doubled in women reporting two or more lifetime sexual partners if they were current smokers, whereas in monogamous women current smokers showed little increase in risk compared with non-smokers (P for interaction = 0.01).
To simplify the analysis, I assume in the benchmark model that only women value marital interaction and the difference between a woman's utility derived from time spent with her mate in monogamous marriage and of that in polygynous marriage is constant, denoted by ( lambda in mathfrak {R}_).10.10
The primary finding of this research is that, during direct competition among second-generation animals, promiscuous line males had greater mating success, but not greater viability, than monogamous line males; promiscuous line females had fewer litters than monogamous line females, and a significant treatment by sex interaction effect on reproductive success suggested a mild fitness load.
Because this is the first description of a hybrid zone between polyandrous bird species, it provides a useful counterpoint to studies of hybrid zones among avian species characterized by monogamous or polygynous mating systems, and we believe that intensive studies of this system should provide insight into the interaction of genes, environment, and behavior in the avian speciation process.
