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}}</ref> The evolution of complex penile morphologies like the foreskin may have been influenced by females.<refname="Diamond">{{REFbook

The external genitalia of primates are marked by an astounding variety of specialized structures, but over the past 65 million years, the prepuce has not only withstood the test of time, it has also evolved in its complexity. The survival and further development of the human penile prepuce in the face of the extraordinarily rapid evolution of humans over the last 7 to 9 million years is particularly noteworthy, especially against the background of a fourfold increase in penile size.<ref>{{REFbook | lastname="Diamond | first=Jared M. | year=1997 | title=Why Sex is Fun: The Evolution of Human Sexuality | url= | editor= | edition= | volume= | chapter= | pages= | location=London | publisher=Weidenfeld & Nicolson | isbn=0465031269 | quote= | accessdate= | note=}}<"/ref>

=== Comparative Anatomy anatomy ===

A histologic study of the penile and clitoral prepuce, carried out on human and non-human primates, showed that corpuscular receptors are concentrated at the prepuce/glans penis and the prepuce/glans clitoridis interface in humans and rhesus monkeys.<refname="macaca">{{REFjournal

| first=C.

The rhesus monkey has fewer corpuscular receptors in the prepuce (foreskin) and more corpuscular receptors in the glans (head). In humans, however, the glans penis has few corpuscular receptors and predominant free nerve endings,<ref>Halata, Z, & Spaethe, A. (1997). Sensory innervation of the human penis. Plenum Press.</ref><ref name="halta86">Halata, Z, & Munger, B. (1986). The neuroanatomical basis for the protopathic sensibility of the human glans penis. Brain Res, 34(506)</ref> consistent with protopathic sensibility. Protopathic simply refers to a low order of sensibility (consciousness of sensation), such as to deep pressure and pain, that is poorly localised. The human glans penis has virtually no fine touch sensation and can only sense deep pressure and pain at a high threshold.<ref>Von, FMF.M. (1894). Beitrage Beiträge zur physiologie Physiologie des schmerzsinnsSchmerzsinns. Akad Wiss Leipzig Math.-Naturwiss Kl Ber.</ref><ref>Cold, C, & Tarara, R. (1920). Penile and clitoral prepuce mucocutaneous receptors in name="macaca mulatta. Vet Pathol, 34(506).<"/ref> While the human glans penis is protopathic, the prepuce contains a high concentration of touch receptors in the ridged band.<ref name="cold-mcgrath"/>