Some animals can have offspring without needing to mate. This event, popularly known as “virgin birth”, occurs through a process called “virgin birth”. female during parthenogenesis It creates an embryo from an unfertilized egg. Descendants, as a rule, are of only one gender – all male or female.

When an animal reproduces only in this way, the process is called obligate parthenogenesis. For animals that normally reproduce sexually, this process is called facultative parthenogenesis. This type of facultative parthenogenesis is generally very rare. From bats to sharks, here are eight virgin-born animals.

Komodo monitor lizard

In 2006, scientists for the first time discovered the Komodo dragon (Varanus komodoensis) may be a virgin. At that time, only two Komodo dragons lived in Europe. One of these dragons, a female at Chester Zoo in England, gave birth to a litter of 25 eggs despite having no contact with males.

Sharks

On an ordinary morning at Omaha’s Henry Doorly Zoo and Aquarium, zookeepers were stunned to discover a 6.5-inch (16.5-centimeter) juvenile shark in an aquarium containing three female capped sharks (Sphyrna tiburo). None of the Caponehead females had ever met a male of the species in captivity, and there were no signs of mating from the various species in the tank.

Spontaneous births like this were once attributed to the female’s ability to store sperm long after it was collected from the wild. However, since female capogolins were collected from the wild three years before puberty, scientists ruled out this explanation. This event genetically confirmed that sharks had undergone parthenogenesis for the first time.

Virgin births have since been observed in zebra sharks (Stegostoma tigrinum), blacktip reef sharks (Carcharhinus melanopterus) and smooth-bottom sharks (mustelus mustelus).

california condor

No thanks! Even when California condors are with males, females (Gymnogyps californianusPeople in critical condition sometimes decide to have children.

Hoping to help revive the population, researchers at the San Diego Zoo mated a female condor to a fertile male. But apparently there was no need for a male: Geneticists testing DNA samples in the laboratory discovered two male chicks carrying two identical copies of their mother’s DNA.

sticks

Unlike other animals, parthenogenesis is not uncommon in sticklebacks. In fact, creatures of the same kind Timema That’s the only way they reproduce, and they’ve been doing it for a million years. But having children without having sex is not ideal: In the long term, asexual reproduction can negatively impact animals’ ability to adapt to environmental changes over time. So like insects Timema Did you manage to survive this long?

The study, published in September in the journal Proceedings of the Royal Society B, examined eight populations of four species: Timema genevievae, T. shepardi, T.monikensis And T. douglasi. It turns out that insidious sex is behind their long-term viability: Two of the four species occasionally resort to sexual reproduction, creating diversity in the gene pool and limiting risk.

blind snake

Blind Brahman Serpent (Ramphotyphlops braminus) is another species believed to reproduce only asexually. So far only females of this species have been found.

peaceful

Tadpoles are microscopic aquatic creatures known for their ability to withstand extreme conditions. These plump water bears can go both ways, reproducing both sexually and asexually. However, parthenogenesis is common only in lake and terrestrial habitats.

alligators

This year, scientists announced the first known case of a virgin crocodile birth. After a female American alligator spent 16 years away from other males (Crocodylus acuteus) laid a clutch of 14 eggs. In 2002, a female crocodile arrived at the Costa Rican zoo Parque Reptilandia. After that he spent all his time alone indoors.

Although the crocodile was able to produce fertilized eggs on its own, the eggs were ultimately not viable. Only seven of the 14 developed during incubation. Only one egg had a fully formed fetus after incubation, but the baby alligator was stillborn. DNA analysis of the fetus confirmed a more than 99.9% genetic match to the female alligator.

shellfish

One of the most striking types of parthenogenesis is sperm-dependent parthenogenesis demonstrated by Amazonian molluscs.Poecilia formosa). These mollinia are named after the all-female tribes in Greek mythology who used only men for reproduction and killed their male children at birth. Like their namesakes, all-female Amazon molinesia depend on male sperm to initiate the formation of a fertilized egg. But there’s a problem: Males come from other related species and don’t contribute genetic material to the egg.