A virgin birth might sound miraculous, but in some animals, this marvel is all natural.
Certain animals like sharks and snakes are capable of producing healthy offspring without ever mating, through a process known as parthenogenesis.
Recently in the US, Charlotte the stingray became pregnant without even seeing a member of her own species.
But was this divine intervention, or just another wonder of the natural world?
This step-by-step graphic reveals the fascinating details of how Charlotte was able to become pregnant, without mating.
Certain animals are capable of reproducing through ‘facultative parthenogenesis’ in which the egg is fertilised with cells from the mother rather than by a male
Recently in the US, Charlotte the stingray became pregnant without even seeing a member of her own species. But was this divine intervention, or just another wonder of the natural world?
Charlotte, a round stingray who has spent much of her life at the Aquarium and Shark Lab in Hendersonville, North Carolina, is expected to give birth to four pups in a fortnight.
But her keepers say that there is no chance that she has become pregnant by mating with another member of her species.
Most animals create their young through sexual reproduction which requires a male and a female to exchange genetic material.
The egg from the mother contains a half set of genes which is completed by the genes contained in sperm from the male.
However, certain animals like sharks, birds, snakes, and even crocodiles are capable of reproducing in a different way.
Scientists believe that Charlotte became pregnant through a process called ‘facultative parthenogenesis’.
During facultative parthenogenesis, the offspring gets its full set of genes from its mother.
Instead of fertilising the egg with a sperm cell, it is fertilised by a cell taken from the mother herself.
This ‘polar cell’, as it is called, bonds with the egg and triggers cell division to begin, leading to the creation of a fully developed embryo.
Since the polar cell also contains half a set of genes from the mother, the offspring is almost a perfect clone of its parent (while accounting for mutations and copying errors).
Scientists believe that Charlotte became pregnant through a process called facultative parthenogenesis which is a type of asexual reproduction
This process is observed in other animals like certain birds, reptiles, and snakes. Scientists have also found the first known crocodile to produce fertilized eggs on its own
Kady Lyons, a research scientist at the Georgia Aquarium in Atlanta where Charlotte the stingray is kept, says Charlotte’s pregnancy is the only example she is aware of for round stingrays.
Ms Lyons says: ‘I’m not surprised, because nature finds a way of having this happen,’ she said.
‘We don’t know why it happens.
‘Just that it’s kind of this really neat phenomenon that they seem to be able to do.’
And while Charlotte does share her 2,200-gallon with five small sharks, her keepers insist that it would have been impossible for her to breed with them.
‘We should set the record straight that there aren’t some shark-ray shenanigans happening here,’ Ms Lyons added.
Charlotte’s offspring will contain only her genetic material, making them near-perfect copies of her
Understanding why certain animals are capable of parthenogenesis and others are not might help us answer whether humans could ever have ‘virgin births’ of their own (stock image)
Scientists are still not quite sure what exactly triggers virgin births or why some animals are capable of it and not others.
But finding out would help answer whether it is possible for humans to reproduce asexually.
For a mammal to have a virgin birth, they would likely need to undergo a slightly different type of parthenogenesis.
Rather than the mother fertilising the egg with a cell from her body, called apomixis, the egg would need to double its genetic content, divide, and then re-combine.
In this process, which scientists call automixis, the egg would end up with the normal number of chromosomes without the need for any additional genetic material.
However, even then it would be a ‘one in a billion’ chance for the egg to start developing into an embryo.
Professor Russell Bonuriansky, an ecologist at the University of South Wales in Australia, told MailOnline that mammals might have evolved to make this kind of reproduction impossible.
Professor Bonuriansky says: ‘Some animals can do this but, for some reason, most can’t.’
‘[It] functions to prevent eggs from developing into embryos inside the ovaries, which would be lethal to female mammals,’ he continued.
However, scientists are investigating how to bring about asexual reproduction in mammals.
Scientists in China have even announced that they were able to achieve parthenogenesis in mice without any male genetic DNA.
