Such research into chimeras elicited little public attention and outcry until August 2003, when Hui Zhen Sheng at the Shanghai Second Medical University created the first human-nonhuman chimera. In 1989, scientists at the University of California, Davis breached this barrier and created the first artificial chimera, a sheep-goat hybrid dubbed the “geep.”

Interspecific chimeras, however, rarely exist in nature due to the unlikelihood of specific conditions required. Chimerism within a species occurs naturally in nearly all animals, including humans. It develops from two fertilized eggs that come into contact and combine to form a single embryo, instead of staying separate and developing into fraternal twins. Technically, a chimera consists of two genomes in a single body, producing two types of cells that work in conjunction to create a viable organism. The debate over chimera research represents the changing perception of humanity and our place in the world.Ĭhimeras differ from the general perception of the genetically modified organism. At closer examination, however, all of these objections stem from an unwillingness to surrender society’s rigid view of human identity and uniqueness. While scientific and public health concerns exist, the majority of the opposition focus on the violation of current ethical and moral codes that arises from creating and using chimeras.

Despite its potential, however, chimera research faces significant opposition from a wide spectrum of the population. Useful applications of this technology range from the study of disease, to more accurate testing of drugs and medication, to the possibility of transplants using chimeric organs. Their utility in science lies in their unique biological integration of both human and animal cells, which can give rise to human tissues and even organs within the body of an animal. These chimeric animals hold enormous potential for the field of medicine as well as basic research into human physiology. Scientists now have created human-nonhuman chimeras-organisms that have both human cells and animals cells in their bodies. Recently, however, advances in genetic engineering and microsurgery have brought these creatures into existence. For most of history, part-human part-animal beings have always resided in the realm of fiction and folklore.

Chimera biology