CATTLE THEORY OF HUMAN PLACEMENT
Although this theory does not include an explination on how life evolved, it is an actual theory. "An actual theory" is defined as a theory that has a group of people who actually believe in it and spread the idea.
The cattle theory is based on the assumption that there is extraterestrial life, and it is more advanced than we (humans) are. These extraterestrials use humans like cattle. They go around to planets, drop human populations, and leave for the humans to expand their populations. The extraterestrials then return to harvest their crop after several thousand years (one common idea is that the human population will be harvested in the year 2000).
While these extraterestrials where on one of their patrols for planets that could be suitable for their human "cattle" they discovered Earth. Finding Earth's atmosphere suitable for humans they they took a closer look at the planet. Discovering that the dominant life form, dinosaurs, could prove detrimental to the survival of the humans they shot the planet with a high-powered missile and marked Earth as a place to return to.
Apon return they discovered the missile had done its job and wiped out the dinosaurs, leaving an opening for a dominant life form. They then planted their human populations in, what is now, Africa, Europe, and North America. They saved South America for their head quarters when they visited to check up on their "stock".
Evidence used to support the Cattle Theory of Human Placement is: odd formations in the forests of South America appear to be landing strips; all gods of the humans live in the sky; temples and holy structures reach upward; and human sacrifice suggests gods like human flesh. Some people even believe that the U.S. government has captured some of the "shepards" and knows what will happen. But remember, there is no proof that this could not have happened.