A leading geneticist has suggested humans are nothing but a monkey-pig hybrid.
Eugene McCarthy, of the University of Georgia said while humans have a number of features in common with chimpanzees, we also have some "distinct" features, the Daily Mail reported.
Only one other animal is believed to share these traits.
"What is this other animal that has all these traits?" McCarthy said. "The answer is Sus scrofa, the ordinary pig."
Researchers have long-believed humans were closely related to primates, but McCarthy suggests humans share traits such as a "thick layer of subcutaneous fat, [light-colored] eyes, protruding noses and heavy eyelashes" with pigs.
The researcher wrote on his unusual theory in an article on Macroevolution.net, although he stresses the relationship is only a theory.
Other similarities between humans and pigs include skin tissue and heart valve structure along with other organs.
The researcher believes the hybridization occurred when the two animals (primate and porcine) lived together during a time of "backcrossing." This occured when pigs lived among and mated with primates, becoming more and more like them each generation.
McCarthy rejects the idea that all hybrids are sterile. In this case, after several generations of mating the breed would have become fertile enough to reproduce freely.
The idea has come under serious scrutiny, especially from creationists.
ScienceBlog dubbed the idea the "Monkey-F******-A-Pig hypothesis," according to the Daily Mail. The blog claimed it was nearly impossible for a pig and monkey to successfully reproduce, it also pointed out the species' are believed to have diverged some 80 million years ago.
"[J]ust the gradual accumulation of molecular differences in sperm and egg recognition proteins would mean that pig sperm wouldn't recognize a chimpanzee egg as a reasonable target for fusion,' PZ Myers wrote in the post. 'Hybridizing a pig and a chimp is like taking half the dancers from a performance of Swan Lake and the other half from a performance of Giselle and throwing them together on stage to assemble something. It's going to be a catastrophe," he said.
McCarthy said he initially felt uncomfortable with the idea of being a hybrid, but has learned to embrace it.
"My opinion of this animal has much improved during the course of my research. Where once I thought of filth and greed, I now think of intelligence, affection, loyalty, and adaptability, with an added touch of joyous sensuality - qualities without which humans would not be human," McCarthy said, the Daily Mail reported.
