What are chimeras and why are they created?
Chimeras (pronounced ki-MER-ahs) result from the mixing of at least two different bodies in one. They occur naturally, such as in the case of twins, which can carry some of the same cells as their siblings with which they shared a womb. And most mothers carry in their blood some cells from each child they have born. People who have received transplants from other humans or animals, such as heart valves from pigs or cows, are also chimeras. Chimeras are also produced by blending human and animal genes. Although it sounds like the stuff of science fiction, many scientists believe the closer an animal resembles a human, the better research model it makes to test medications or grow parts for transplanting into humans. So researchers have been injecting human cells into lab animals for years, but more recently have been creating more exotic hybrids, such as pigs with human blood and mice with human brain cells. The term “chimera” comes from Greek mythology and refers to a creature that had
