]In the comic, Predator: Homeworld, the two hero thinking about where the Predators evolved. Are they from Earth? Maybe they evolved from our planet many millenia ago, but somehow they left the planet? The woman's theory in the comic is this: the Predators evolved in Earth, but left, because they are bored, so they constructed spaceships to travel between the stars (this theory is wrong in my opinion, because none of the comic, books, films and games mentions, or hints this, we dont see any predator ruins, artifacts, or anything else). However the second theory is correct, an unknown species watched the young predator species and thought they are promising for their porpuse.
So the Predators are not aliens, but a lost race. This explains why the Super Predators wants to colonize the Earth in the The Predator. Yeah, maybe you thinking about this: "but in the first AvP film, we see them teaching the humans, so why didn't they just massacred them, or conquered them?" Well, the answer to this questin is simple: the Predators dont't exterminata races, or wage war against them. Yes, they sometimes goes to war, but not to conquer, it's just self defence. In conclusion: only the Bad Bloods wants to colonise the Earth, the "good" hunters only wants to hunt.
So back to the main question: if we accept that the Yautja species origanete from Earth... than who found and removed them from the planet completely? Well, here is my theory, that connects a ton of hints from the EU.
We know some race, that observed Earth: let's see them.
Giffs from the novel: Aliens: Steel Egg. They are one of the candidates, but we could ignore them, because the unknown race removed the Predators millions of years ago, and the Giffs only come to Earth when the Roman Empire was still young.
Drukathi: one of the most advenced race, even the Yautjas fear them (hinted in Alien vs. Predator: Armageddon), they are the puppet masters behind the Rage. We know, that they destroyed entire civilisation, or made alliances to others. But... why should the Drukhati oversee the evolution of the Predators? It doesn't make sense.
Space Jockey, also know as Mala'kak: another advenced race, that made a great galactic empire (the Earth was also part of it), before the Xenomorphs destroyed it. But as the Drukathi, why would the Space Jockeys capteured, then brought the Yautjas to the Yautja Prime what is far, far away from Earth?
Engineer (and yes, they are NOT Space Jockeys, they are two different race). We see in the movie Prometheus, that they created life in Earth. Thanks to a recently leaked script, we know this: the Engineers once met az unkown creature. They worshiped it as a god. A Chosen Enginner sacrificed himself to this God, to give birth to a Deacon. In excange for this the god gave the entire Engineer race a long lifespawn, they could easily live thousand of years now. But in time they lost the ability to reproduce, so sooner or later they are going to extinct.
Before we going forward! What or who was this "god"?
We known, that it created a Deacon, a nearly Alien creature. In this time period only the Space Jockey and the Drukathi had aliens. However the Drukathis created the xenos (to proof this, I can make another post about is) to purge the Jockey empire. In my opinion, the Jockey wanted to create something, to counter the Alien threat, fight against fire with fire, thus they created the Deacons/proto xenos. We know from the Alien: Covenant novel, that the proto aliens/white things and the xenos attack each other. In conclusion: maybe this "god" was a Space Jockey, this also explains why are the Engineers technology is soo similar to the Jockey. Also, the Jockeys are big creatures with really strong mind, capable to control entire ships with their mind, or to communicate with other races without opening their mouth. And they live like forever, we know that at least one Jockey lived nearly 1,6 billion year long.
Because the Jockeys are nearly exterminated via the xenos (Aliens: Apocalypse comic), and the Drukhari left our galaxy (mentioned in the AvP: Armageddon novel), the Engineers were alone in this wast galaxy. According the leaked Prometheus script, the dying Engineers wanted to find a succesor species, who carry on their legacy. They didn't find them, so they started creating new races via the black goo.
So back to the main question! The Engineers last hope was Earth, what a coincidence! So we find a race, that oversaw the evolution of the Predators and brought them to another planet. Yes, the Yautjas meant to become the successor of the Engineers! But... they failed, as will the humans, who cruified the Engineers chosen man (emissary), Jesus Christ.
But you may ask, this: "the Engineers left their marks in the artificaly created races culture, e.g: they worshiped them, or left starmaps like in Earth." So, let's check out the Yautja's mythology, ancient tales, to find something!
Well stunningly I found evidences to support my theory! The Predators are worship many gods, like the Black Warrior (Death), the Thunder God (Odin in our mythology), who is the war god. Even we got this phrase: "thin-de le'hsaun 'aloun'myin-de s' bpi-de gka-de hou-depaya" or in English: "learn the gift of all sights or finish the dance of the fallen gods". AND we see in the Predator: Homeworld comic, that some bad bloods worship some unknown god and this is a very big sin, punished by death.
What if this "fallen gods" are in fact the Engineers? Heck, we even see in the Fire and Stone comics, that Ahab wants to kill the Engineers in pure rage. So we have the Engineers who are worshiped by many race and we got the Yautja fallen gods who are hated, connect the two and we got this theory.
But why they hate the "fallen gods"? Well, maybe the Engineers did something very, very bad for the Predators. This could explain the Predators "only the strong survives" attitude, back then maybe the Engineers nearly wiped them out, the planet's resources was very low, so the Yautjas can't afford the luxury to let the weak Preds to survive.
Thank you for reading this theory, what is connects a bounch of hints from various novels, comics, films and games. I think this is make sense, anyway I loved to connect the dots, making the puzzle whole. What do you think? I have a ton of other theory and lore breakdown to come, like what happened to Alan "Dutch" Schaefer, who created the Xenos, or the occult things in the AvP universe.
P.S.: If I made some error in the grammar I am sorry, I am not a native english speaker, and I really really long ago wrote something in English (meanwhile I perfectly understand the English, but I have some difficulty to write or speak).