Humans have been obsessed with cats ever since we got them to live with us. Many cat owners suspect that we have not managed to domesticate these animals, but rather persuaded them to deign to live with us. Even in Ancient Egypt, cats were treated comfortably and given a dignified burial in wealthy families.
If we were obsessed with cats 6,000 years ago, it’s only natural that, thanks to the internet, we now see the most beautiful cats from around the world and make them famous as if they were Hollywood celebrities. This is how a cute kitten named Pebbles has become the viral cat of the year. This majestic cat has become a social media sensation. Her appearance is so unusual that she looks like she was created by an artificial intelligence filter or during a Photoshop session by an expert photographer.
Pebbles, one of the most eye-catching cats in the world
Pebbles has a very distinctive coat: her face is perfectly divided into two different colors, as if it had been drawn right down the middle of her head. So much so that people often ask in comments if it’s an optical illusion or —literally— “two cats in one.” Pebbles‘ owner, who documents her on the TikTok account @chimerapebbles, assures us that her beauty is 100% natural.
Pebbles is a Ragdoll cat, a breed famous for its intense blue eyes and docile behavior. In this cat’s case, these eyes are combined with a perfectly divided color pattern, which makes her even more mesmerizing. But how is it possible for her to have this coat? Behind her unique appearance is the amazing phenomenon of genetic chimerism.
Chimeras, an embryonic miracle
If you remember correctly, chimeras were fearsome mythological monsters in ancient Greece. They were beasts with the head of a lion, the body of a goat, and the tail of a snake. Biology students found it an apt term to describe an organism composed of different parts. When we talk about a chimera in real life, we are referring to an individual that has two distinct cell populations. Each population contains different DNA genetic codes.
This is not a simple mutation, but rather a biological miracle that occurs in the womb and is very rare. The exact process is called tetragametic chimerism, which occurs when two separate eggs are fertilized by two different sperm. In a normal pregnancy, these two fertilized eggs would develop into two fraternal twin babies. However, in an extremely rare and accidental event, these two embryos may spontaneously fuse in the very early stages of embryonic development. This would result in a single organism with two different DNA strands.
This is why Pebbles has such unusual fur: her cells combine two different sets of DNA, giving her fur patterns that would normally be found on two separate cats. Fortunately, despite its genetic complexity, the phenomenon of embryonic chimeras does not usually have long-term negative effects on the health of cats. Most feline chimeras tend to live long, happy, and completely normal lives.
Other genetic oddities in cats
Aside from chimerism, another adorable genetic mutation that fascinates cat lovers is polydactyly. This is the gene responsible for some cats having extra toes on their paws.
This gives them a very comical appearance, as if they were wearing gloves or had rudimentary thumbs. Polydactyly is caused by a genetic mutation in the ZRS gene. It is a dominant gene, which means that if only one parent carries the gene, there is a 50% chance that their offspring will have those extra toes. It is estimated that one in every 1,000 cats in the world is polydactyl (a much more common genetic mutation than chimerism).
Thanks to the writer Ernest Hemingway, most cat lovers are familiar with polydactyly. This legend began when a ship captain gave him a white kitten named Snow White who had two extra toes. Today, at Ernest Hemingway’s museum and home in Key West, Florida, there is still a large colony of cats descended from Snow White… who continue to have their extra toes.