Human history
At this time the galaxy had just gone through a long and bloody war. Diplomats from positive and negative races sought places where the positive and negative races could work together on something, to defuse tensions and focus the galaxy’s attention away from war and towards some new goal.
Those diplomats hoped that Earthlings could serve as a great “peace project.” Namely: let all prominent races in the galaxy contribute some DNA to these ape-like Earthlings (plus Reptilians contributed the lizard brain). Then negative and positive races could work together towards one goal, namely creating a new kind of Earthling. And they could have a friendly competition that would focus their attention away from war.
This competition was: if a race has DNA from negative and positive races, will it turn towards the light or towards the dark?
In popular terms, this experiment was hyped as, “which is stronger, the light or the dark? Earthlings will definitely settle this argument.”
Both the positive and negative races were convinced these Earthlings would eventually turn to their side. So this was considered to be a very interesting experiment. And this Earthling experiment did help to defuse war tensions.
The experiment also had an inherent grand prize. Earthlings are the psionically more powerful race in the universe, because of their diverse DNA. So whichever side Earthlings turn to, gets the prize of having the most powerful race in the universe be on their side.
The Annunaki allowed the other races to tinker with Earthlings, and eventually, they had enough minerals and they left.
What you think of as the Earthling race, are those Earthlings who have received all the DNA from various ET races. This is why Earthlings are so diverse and why so many Earthlings look very different from one another. This is because different Earthlings have different combinations of ET DNA. That said, all groups of Earthlings have both good and bad traits, strengths and drawbacks. No one group on your planet is better than another.
The positive races offered Earthlings a helping hand. Earthlings accepted and the positive races helped you build Atlantis (which was more masculine-focused) and Lemuria (which was more feminine-focused). Then the positive races left, to honor the spirit of the “will Earthlings turn towards the light or dark” competition.
But the dark races cheated. They lied to Earthlings, which is a violation of free will, and they infiltrated both Atlantis and Lemuria. I would like to say that they corrupted Atlantis and Lemuria, but it is more accurate to say that they merely contributed to the corruption of Atlantis and Lemuria.
The dark ones gave you destructive technology and flattered you and increased your ego and pride and turned you away from a path of service to Source.