Top 9 Nature’s Virgin Births: The Scientific Evidence of Parthenogenesis

Our first example is the Komodo dragon, the largest living lizard on Earth. In 2006, scientists at the Chester Zoo in England reported two cases of parthenogenesis in captive female Komodo dragons (Watts et al., 2006). These resourceful reptiles can reproduce through parthenogenesis when no males are present, ensuring the survival of their species in isolated habitats.

In 2007, researchers at the Henry Doorly Zoo in Nebraska documented the first known case of a hammerhead shark giving birth through parthenogenesis (Chapman et al., 2007). This fascinating discovery shed light on the reproductive flexibility of these incredible marine predators.

Bdelloid rotifers are minute organisms, typically ranging from 150 to 700 µm in length, and can be found in freshwater habitats. With over 450 described species, bdelloid rotifers are differentiated mainly by their physical characteristics. The main features that differentiate bdelloids from related rotifer groups- are their exclusive ability to reproduce through parthenogenesis- and their capability to endure dry and harsh conditions- by entering a state of desiccation-induced dormancy- known as anhydrobiosis- at any stage of their life cycle. They are often called "ancient asexuals" due to fossil evidence showing their unique history of asexual reproduction- dating back more than 25 million years. In June 2021, scientists reported the successful revival of bdelloid rotifers that had been frozen for 24,000 years in Siberian permafrost (Shmakova et al., 2021).

Whiptail lizards are another intriguing example of parthenogenesis. Several species, such as the New Mexico whiptail (Aspidoscelis neomexicana), reproduce exclusively through parthenogenesis, and their populations are entirely female (Lutes et al., 2010). These lizards have evolved this unique reproductive strategy to adapt to their changing environments.

Aphids are small insects that can reproduce both sexually and asexually. Many species, like the pea aphid (Acyrthosiphon pisum), rely on parthenogenesis for rapid population growth, especially during favorable environmental conditions (Martel et al., 2020). This fascinating reproductive strategy helps them colonize new habitats quickly and efficiently.

Stick insects, or phasmids, are another fascinating group of organisms that exhibit parthenogenesis. Some species, like the Timema cristinae, reproduce through parthenogenesis when males are scarce (Schwander et al., 2011). This reproductive strategy allows them to persist and adapt to changing environments.

Water fleas, or Daphnia, are small crustaceans that typically reproduce asexually via parthenogenesis. Sexual reproduction occurs only under certain environmental conditions, such as overcrowding or limited resources (Ebert, 2005). This dual reproductive strategy enables Daphnia to respond to environmental changes and maintain genetic diversity.

Although honeybees usually reproduce sexually, unfertilized eggs can develop into male drones through a process called arrhenotokous parthenogenesis (Oldroyd et al., 2008). This phenomenon ensures that even in the absence of a queen or a mate, a colony can still produce male offspring and contribute to the overall gene pool.

Parthenogenesis isn’t just limited to the animal kingdom; it also occurs in plants. For example, dandelions (Taraxacum spp.) are known to reproduce asexually through a process called apomixis (Van Dijk et al., 2009), which allows them to produce genetically identical offspring without fertilization. This adaptation helps dandelions spread rapidly and colonize various environments.

Chapman, D. D., Shivji, M. S., Louis, E., Sommer, J., Fletcher, H., & Prodöhl, P. A. (2007). Virgin birth in a hammerhead shark. Biology Letters. https://doi.org/10.1098/rsbl.2007.0189

Ebert, D. (2005). Ecology, Epidemiology, and Evolution of Parasitism in Daphnia. National Center for Biotechnology Information. https://www.ncbi.nlm.nih.gov/books/NBK2036/

Lutes, A. A., Neaves, W. B., Baumann, D. P., Wiegraebe, W., & Baumann, P. (2010). Sister chromosome pairing maintains heterozygosity in parthenogenetic lizards. Nature, 464(7286), 283–286. https://doi.org/10.1038/nature08818

Martel, S. I., Ossa, C. G., Simon, J.-C., Figueroa, C. C., & Bozinovic, F. (2020). Latitudinal trend in the reproductive mode of the pea aphid Acyrthosiphon pisum invading a wide climatic range. Ecology and Evolution. https://doi.org/10.1002/ece3.6536

Oldroyd, B. P., Allsopp, M. H., Gloag, R. S., Lim, J., Jordan, L. A., & Beekman, M. (2008). Thelytokous Parthenogenesis in Unmated Queen Honeybees (Apis mellifera capensis): Central Fusion and High Recombination Rates. Genetics, 180(1), 359–366. https://doi.org/10.1534/genetics.108.090415

Schwander, T., Henry, L., & Crespi, B. J. (2011). Molecular Evidence for Ancient Asexuality in Timema Stick Insects. Current Biology, 21(13), 1129–1134. https://doi.org/10.1016/j.cub.2011.05.026

Shmakova, L., Malavin, S., Iakovenko, N., Shain, D., Plewka, M., & Rivkina, E. (2021). A living bdelloid rotifer from 24,000-year-old Arctic permafrost. Current Biology, 31(11), PR712–R713. https://doi.org/10.1016/j.cub.2021.04.077

Van Dijk, P., de Jong, H., Vijverberg, K., & Biere, A. (2009). An Apomixis-Gene’s View on Dandelions. In I. Schön, K. Martens, & P. Dijk (Eds.), Lost Sex: The Evolutionary Biology of Parthenogenesis (pp. 475–493). Springer Netherlands. https://doi.org/10.1007/978-90-481-2770-2_22

Watts, P. C., Buley, K. R., Sanderson, S., Boardman, W., Ciofi, C., & Gibson, R. (2006). Parthenogenesis in Komodo dragons. Nature, 444(7122), 1021–1022. https://doi.org/10.1038/4441021a