You’ve probably seen the above picture before — it’s one of Venus the cat, an animal that became famous because of their unique outward appearance. But what if I told you that there was a specific name for this abnormality, and that it’s much more common than you think it is (though not as obvious)?
The name for this is ‘Chimera’ — no, it’s not the one in the Greek myth, but that’s what it’s named after. Chimeras happen when a single living thing is made up of DNA from two different biotic elements.
Now, you might be wondering: isn’t that what happens anyways? You get genes from your mom and your dad? But there’s more to this than that. It’s when there are two different types of DNA programmed to create two different organisms.
There are many different types of human chimeras, but professionals speculate that the most typical ones are formed when they are in the mother’s womb. If a mother is carrying twins, they may end up merging into one child. This is called a dispermic chimera. This child may have different colored eyes, hair, different blood types, and possibly different gendered parts.
Other types of human chimeras are microchimeras and androgenetic chimeras. Microchimeras are not well understood, but they can happen during blood transfusions and pregnancy. A few cells from another person travel into the host’s body. This can be both good and bad. It can be good when a person’s organ is damaged and their cells can’t repair it — then the alien cells may do it for them. But it may be bad because it can increase the risk of autoimmune diseases. This doesn’t create another human, it just changes a preexisting one.
Androgenetic chimeras occur when a fetus has cells with female and male chromosomes, but it also has male-male chromosomes. They may not ever be born because of complications, and may die in the womb. If they are born, they usually experience many disorders.
Human chimeras are way more common than scientists initially thought, and this poses as a problem in some cases. For example, it would be hard to identify a child’s mother if that mom was genetically two people. And if somebody commits a crime, DNA testing wouldn’t identify them if the second, alternate DNA type was the one found at the crime scene. Different blood types are also mixed together.
And did you know that regular cells can start chimeras too?! If one cell splits, it makes another cell, right (let’s name it cell B)? So if a whole group of cells splits and splits from cell B, it is totally different from the other cells in your body! Cool, right? This happens all the time, and usually doesn’t show any effect. But some of the most dangerous chimeric cells are those that we call ‘cancer’. They’re different from the rest, and they split at a faster rate. It is disastrous in some cases.
Finally, this opens up a whole new window for genetic modification. Animal-human hybrids, and i daresay plant-animal hybrids? The possibilities are endless. And dangerous. There are hundreds of scientists right now debating the ethicality of these experiments.
What can I say? This topic is taking up the science world in a cy-clone! (Haha, get it?)