A chimera is vitually a single organism that is made up of cells from two or more “individuals”—that is to say, it contains two sets of DNA, with the code to make two separate organisms.
what does a human chimera look like
One way that chimeras can happen naturally in humans is that a fetus can absorb its twin.
The idea of creating human-animal chimeras by researchers has generated controversy earlier on, and may bring up ideas about Frankenstein-ish experiments. But chimeras are not always man-made—and so to say there are a number of examples of human chimeras that already existed.
A chimera is essentially a single organism that’s made up of cells from two or more “individuals”—that is, it contains two sets of DNA, with the code to make two separate organisms.
One way that chimeras can happen naturally in humans is that a fetus can absorb its twin. This can occur with fraternal twins, if one embryo dies very early in pregnancy, and some of its cells are “absorbed” by the other twin.
The remaining fetus will have two sets of DNA cells
These individuals often don’t know they are a chimera.
For example, there was a news in 2002, which reported the story of a woman named Karen Keegan, who needed a kidney transplant and so had to undergo genetic testing along with her family, to see if any of her family member could donate one to her. But the tests suggested that genetically, Keegan could not be the mother of her sons. A mystery right?
Tho it was solved when the doctors discovered that Keegan was a chimera—she had a different set of DNA in her blood cells compared to the other tissues in her body.
Another form of chimera
A person can also be a chimera if they undergo a bone marrow transplant. During such transplants, which can be used for example to treat leukemia, a person will have their own bone marrow destroyed and replaced with bone marrow from another person.
Bone marrow contains stem cells that develop into red blood cells. This means that a person with a bone marrow transplant will have blood cells, for the rest of their life, that are genetically identical to those of the donor, and are not genetically the same as the other cells in their own body.
In some cases, all of the blood cells in a person who received a bone marrow transplant will match the DNA of their donor.
But in other cases, the recipient may have a mix of both their own blood cells and donor ones, some time ago in 2004, a paper review that in the journal Bone Marrow Transplantation.
A blood transfusion will also temporarily give a person cells from someone else, but in a bone marrow transplant, the new blood cells will be permanent. according to the Tech Museum of Innovation in San Jose, California.
More commonly, people may exhibit so-called microchimerism—when a small fraction of their cells are from someone else. This can happen when a woman becomes pregnant, and a small number of cells from the fetus migrate into her blood and travel to different organs.
A study some time ago suggested that this happens in almost all pregnant women, at least temporarily.
The researchers tested tissue samples from the kidneys, livers, spleens, lungs, hearts, and brains of 26 women who tragically died while pregnant or within one month of giving birth. The study found that the women had fetal cells in all of these tissues. The researchers knew that the cells were from the fetus, and not from the mother, this is because the cells contained a Y chromosome (found only in males) and the women had all been carrying sons.
And sometimes fetal cells might stay in a woman’s body for years. In a 2012 study, researchers analyzed the brains of 59 women ages 32 to 101, after they had died. They found 63 percent of these women had traces of male DNA from fetal cells in their brains. The oldest woman to have fetal cells in her brain was 94 years old, suggesting that these cells can sometimes stay in the body for a lifetime.
Chimera: In medicine, is refered to a person composed of two genetically distinct types of cells. Human chimeras were first discovered with the advent of blood typing when it was found that some people had more than one blood type
However, I would simply say that chimera humans are natural phenomenon, a medical mystery that has not been fully understood even till now. And moreover, human chimera’s are very rare and beautiful to behold, a physical example of human chimera is having two different skin colours, like having one of your hand dark and the other fair