Wikipedia tells us that a chimera is an animal that has two or more different populations of genetically distinct cells that originated in different zygotes. What this means in practice, is a person originally had a twin that, during gestation, fused with them. The remaining twin is then born with both twins' genetic baggage. What does this create? Mothers who are not genetically related to their children and a half-male, half-female AND half-black, half-white baby.