Last year, headlines were bursting about two cases of human "chimeras."
In the first, singer Taylor Muhl of California discovered that she had two types of DNA: her own and a nonexistent twin sister. That is, in her mother's case, two separate eggs were fertilized by two different sperm, but Taylor absorbed the genetic traits of the second embryo in the early stages of development.
In Greek mythology, a chimera is a monster with the head of a lion, the body of a goat, and the tail of a snake. But in biology, a chimera is a person composed of cells from more than one set of DNA.
The second case is the father who discovered that his son is not his, but his unborn twin brother's. That is, he has two genetic structures: his own and that of his twin brother, who died in the womb in the early stages of pregnancy. He absorbed the genetic load of his twin brother and passed it on to his son. Thus, he discovered that he was in fact his son's uncle and his nonexistent twin brother was his biological father.
In recent years, more and more such cases have been discovered, and researchers have recently concluded that human chimeras are much more common than we can imagine.
One case that intrigued researchers was the case of a woman who discovered that she was both the mother and uncle of her daughter.
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