Deep in the Amazon lives a tribe of lesbians who reproduce without the involvement of penises, sperm, or any males at all.
Whiptail lizards, Cnemidophorous uniparens, lost all of its males somewhere along the evolutionary cycle. Females now reproduce by female-female sex. As described in Aarathi Prasad’s Like A Virgin: Exploring the Frontiers of Conception:
While the lizard is on top, it will intermittently rub its cloaca against the back of the passive female, stroking the back and neck with its jaws and forelimbs. The active female then grasps the back of the neck or shoulder of the passive female in its jaws and begins to curve and force its tail beneath the others’ tail, so that the cloacae of both are brought into close contact, somewhat as a male lizard would so in order to erect one of its two penises through its cloaca.
Once the orifices of both females are in contact, the courting female shifts its jaws to grip the lower half of the mounted females body. This forces the couple to adopt the contorted posture characteristic of mating lizards of opposite sexes.
Obviously questions remain. We do not know how this female-on-female sexual act causes the eggs in the passive female to “activate” as if fertilized and begin dividing into embryos, and we do not know if this pseudo-copulation is required to start the process. There is evidence of solo females reproducing in captivity without another female’s assistance.
We also do not understand how this lizard passes on DNA correctly. Typical sexuality combines half the maternal and and half the paternal DNA to give the child a new full set, but these lizards start with twice the normal DNA so halving it again gives their children a full set.
Once again, God and Mother Nature laugh at our formerly simplistic ideas of how sex works.
* A cloaca, by the way, is the name for the vent in the rear of many birds, fish, mammals, reptiles and others that serves as the single orifice for the intestines, urinary tract, and reproduction. Descriptively enough, the word comes from Latin, meaning sewer.