Males Not Required
Some whiptail lizard species are entirely female and reproduce through cloning — but they still perform mating rituals with each other.
Several species of whiptail lizards have completely eliminated males from the equation. These all-female species reproduce through parthenogenesis — essentially cloning themselves.
The offspring are genetically identical to their mothers, as there's no contribution from male DNA. Yet remarkably, females still perform mating behaviors with each other. One female will play the "male" role, mounting and going through the motions of mating.
This pseudo-mating serves a real purpose: it stimulates ovulation. Females that engage in this behavior produce more eggs than those that don't. Hormonal cycles cause females to alternate between playing "male" and "female" roles throughout the season.
These species likely originated from hybridization between two related species. The hybrid offspring were sterile in the traditional sense but could reproduce through parthenogenesis. Over time, they've become fully independent all-female species.
The disadvantage of this system is lack of genetic diversity — all offspring are clones. This makes populations vulnerable to diseases or environmental changes. But the advantage is efficiency: every individual can produce offspring, doubling reproductive potential compared to species with males.