The Evolutionary Biology of Human Female Sexuality - Tapa dura

"The authors provide an impressively up-to-date, thorough, and evenhanded review not only of recent work on human sexuality in relation to ovarian cycle stage, but also of relevant research on other taxa and of the latest theoretical and empirical work on sexual selection and antagonistic coevolution of the sexes. The result is a tour de force, and those who wish to refute it will have to come to grips with its forceful argumentation and impressive breadth of information."--The Quarterly Review of Biology

Research conducted over the last fifteen years has placed in question many of the traditional conclusions about the evolution of human female sexuality. Women have not lost estrus, as earlier researchers thought, but it is simply concealed, resulting in two functionally distinct sexualities with markedly different ends in each phase.
At the fertile phase of the cycle, women prefer male traits that may mark superior genetic quality, and at infertile phases, they prefer men willing to invest resources in a mate. Thus, women's peri-ovulatory sexuality functions to obtain a sire of superior genetic quality, and is homologous with estrus in other vertebrates.
This model sheds light on male human sexuality as well: men perceive and respond to women's estrus, including by increased mate guarding. Men's response is limited, compared to other vertebrate males, implying coevolutionary history of selection on females to conceal estrus from men and selection on men to detect it. Research indicates that women's concealed estrus is an adaptation to copulate conditionally with men other than the pair-bond partner. Women's sexual ornaments-the estrogen-facilitated features of face and body-are honest signals of individual quality pertaining to future reproductive value.