From Greek mythology to the Virgin Mary, the concept of a “virgin birth” has captivated human imagination for millennia. Scientifically, this phenomenon is called parthenogenesis (Greek: parthenos, “virgin” + genesis, “birth”), and while it sounds like science fiction, nature suggests otherwise.

Parthenogenesis in the Animal Kingdom

Parthenogenesis is not just a mythological concept; it’s a documented reproductive strategy in various species. Over the past few decades, scientists have observed this phenomenon in:

• Reptiles: Species like the Komodo dragon can reproduce without males. In 2006, scientists confirmed that female Komodo dragons could lay viable eggs without any male involvement. As researchers noted in Nature:

“This reproductive plasticity indicates that female Komodo dragons may switch between asexual and sexual reproduction, depending on the availability of a mate.”

• Birds: Instances have been recorded in turkeys and, more recently, in California condors. According to Reshma Ramachandran, a researcher at Mississippi State University who studies bird parthenogenesis, this phenomenon may be far more widespread than currently known.

“Pigeons, zebra finches and chickens—and now condors—come from distinct bird families,” she notes. “There’s no real answer as to why a population might show parthenogenesis, but I’m certain that there’s other instances of parthenogenesis we’re missing. I think the percentage of birds with it will go way higher.”

• Fish and Amphibians: Parthenogenesis has been observed in captive fish, but a Current Biology study offered the first genetic proof of wild-born parthenogenic offspring in a normally sexual vertebrate—the critically endangered smalltooth sawfish.

“What the DNA fingerprints told us was altogether more surprising: female sawfish are sometimes reproducing without even mating,” said Andrew Fields, coauthor of the study.

All seven parthenogenetic offspring were female and showed genetic patterns incompatible with sexual reproduction. As evolutionary biologist Warren Booth noted,

“Facultative parthenogenesis is a more common occurrence than people would ever expect.”

• Mice: While parthenogenesis doesn’t occur naturally in mammals, a 2004 study successfully created a mouse from two female genomes using genetic engineering. The mouse, named Kaguya, survived to adulthood and even reproduced—proving that mammalian parthenogenesis is possible in the lab, but only with precise manipulation of imprinted genes. Patrick Tam, head of the embryology unit at the Children’s Medical Research Institute in Westmead, Australia, commented on the breakthrough in The Scientist, explaining that:

“When you put these two sets of chromosomes together functionally, the individual would have a father-like genome with the original mother genome, and therefore it works and gives rise to a [viable organism].”

This delicate engineering involved mimicking the role of a paternal genome—something nature doesn’t do on its own.

Well… what about humans?

In humans—and mammals in general—parthenogenesis doesn’t occur naturally. As mentioned earlier in the case of mice, this isn’t just because it’s rare, but because it’s biologically blocked. Our cells carry special markers through a process called genomic imprinting, which lets the body know whether a gene came from the mother or the father. Many genes crucial for development only work if they come from the right parent—some must be paternal to switch on. Without that precise balance, the embryo can’t survive. In labs, scientists have managed to “trick” this mechanism in mice using genetic editing, but in nature, parthenogenesis hits a wall.

However, sometimes biology gets… confused. And when it does, strange and fascinating things can happen:

1. Molar Pregnancy

This is what happens when an egg is fertilized—but something goes horribly wrong. In a complete molar pregnancy, an egg with no maternal DNA is fertilized by sperm. Instead of forming a baby, it becomes an aggressive mass of placental tissue. It grows rapidly and can become cancerous if untreated. It’s like the sperm tried to build a baby with no help—and built a tumor instead.

2. Partial Molar Pregnancy

In this case, the egg does have DNA, but it gets fertilized by two sperm—resulting in too much paternal DNA. A malformed fetus may begin to develop, but it can’t survive. This again highlights how delicate the balance between maternal and paternal genes is, and how deviations lead to failure.

3. Teratoma

This is when an unfertilised egg starts dividing on its own, without any sperm. It doesn’t grow into a baby, but into a tumor full of human-like tissue—teeth, skin, hair, even eye structures. It’s the closest thing we have to accidental, human parthenogenesis: a desperate egg trying to build a human body… and failing into horror-movie territory.

4. Chimeras

Sometimes, two embryos fuse into one early in pregnancy. This creates a person with two sets of DNA, often without even knowing it. Some chimeras have different DNA in their blood than in their skin—or even in their ovaries. It’s not quite parthenogenesis, but it’s another example of how messy early development can get.

Conclusion

So, could a human ever be born without a father? Nature’s answer is a firm no. Between imprinted genes, biological checkpoints, and centuries of evolutionary safeguards, the idea of a natural virgin birth in humans remains firmly in the realm of mythology. Yet biology doesn’t always follow the rules. From teratomas to molar pregnancies to mysterious chimeras, the human body occasionally glitches—producing eerie echoes of what parthenogenesis might look like, if it were ever allowed. These bizarre failures remind us just how precise, fragile, and strangely creative human reproduction really is.