Aliens have visited earth many years ago and have influenced greatly our civilization. The people , being unable to describe them in any other way, attributed them supernatural characteristics and thought they were gods from the heavens. Aliens carried out a series of genetic experiments creating many hybrid creatures , half men half animal probably in an effort to improve the gene pool of humans. These monsters later become an object of the ancient myths. In fact scientists are bewildered by one strange fact about human evolution. In a span of several thousand years the size of our brain literally tripled, which happens usually in the course of many thousands of years. The evolution science is also still unable to explain that curious fact. The so called missing link in the human genealogy, the half ape man is still not found. According to one theory in the modern ufology people were created as slaves by aliens in order to work in their mines. Aliens used these mines probably to mine gold for their spaceships. Gold was used probably as a heat shield in their space ships or in electronics.
A fact that corroborates these hypothesis is mines which were discovered in South Africa and Peru , which were dated 50000- 100000 years ago. At that time humans lived in the stone age and were unable to dig these mines.
Another evidence for that comes from the ancient Sumerian texts. According to them the ancient Sumerian Gods called Anunaki came to Earth in order to mine gold. For that purpose they used humans as slaves in their mines. Anunaki gave to the Sumerians all of their knowledge about the stars and planets. They even knew about the planet Neptune long before its discovery in 18 Th century.
Another interesting fact about these alien gods is that they interbred with humans. As a result of that a race of half men half god appeared as Heracles and many other.