Parthenogenetic species - for example water fleas - reproduce asexually, without need of a male, mating or pollination. In parthenogentic animals, the offspring are usually all female, and in certain types of whiptail lizards, the entire species is female. Parthenogenesis often happens where there are no males of a species in the vicinity. In some cases, should males make a reappearance, the species can switch back to sexual reproduction. Recently in zoos, komodo dragons were discovered to be capable of this reproductive trick.

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