Humanity does not come originally from Earth, but from the area of Sirius, which have been created race of advanced civilization or for the fight. the protection of this civilization, which, although advanced lost the ability to defend itself against the aggressor.
These races were genetic manipulation adapted to fight, were bred so that it exhibited a certain hardness, cruelty and barbarism to resistance. It will also be gene. handling shortened life span to 100 years.
This is to be nevzbúrili and turn against their creators. These concerns were later filled and these warlike race were already unruly, so their creators decided to simply exterminate them.
After many millennia to arrive in our solar system on Mars and a small / Phaethon and later destroyed by Malon and dead Mars to Earth.
But these genetically manipulated (ie. The ancestors of today’s earthly people) were also on Earth unmanageable and unpredictable and so friendly tilting of the creators could not rule over them as intended.