Our DNA seems to have been manipulated in the past by beings that passed themselves off as Gods. In Sumer, the alien race of "gods" were known as the Anunnaki.
In Greece, the Annodoti. In the Celtic lore, the Tuatha de Danaan. In the Semetic scriptures (Torah, Talmud, Old Testament, and other Apocryphal texts like the Book of Enoch), they are called The Nephilim, The Sons of God, or The Watchers.
These Anunnaki are said to occupy another planet in our solar system (known to scientists searching for it as 'Planet X'). This planet is called Nibiru by the ancient Sumerians, and is said to have a long elliptical orbit of 3600 years.
This planet, unlike other planets in our solar system, moves clockwise, rather than counter clockwise.