What if all the forms of reported aliens are actually the pro-creators of worlds? Each world in this universe, seeded with parts of DNA from each species, left to evolve and in that process of evolution and civilization or self-destruction, a new component to the universe is complete?
What if each alien culture is a hybrid itself, and unites with other aliens to use DNA from each as the raw material for our world (a kind Adam and Eve without mating)?
Many ancient alien advocates point to the advancement in man's brain and technology along the way being a jump that defied evolution. Scientists counter that with the point that man suddenly got more protein in his diet, but then that certainly didn't make lions particularly more cognizant and intelligent with their high-protein diets. It could be conceived that what we consider evolution was simply "revisions" and that "revisions are still happening" (alien interventions/abductions). In fact, given plants and animals as sources of food, it might be that it was yet another test of our will as a people to consider ourselves beside the animals or above them in a food chain.
What if the randomness of our own trek here on earth, given their DNA, this planet and its resources, we have proved yet another unique concept to a universe made up of so many unique and random crap shoots that more and more knowledge is gained about the process of conditions, DNA manipulation, atmosphere, resources, and the individual souls and the universe becomes more varied, more knowledgeable and more humbled by its own infinite possibilities?
Some day, in fact, might we be seeding another world ourselves perhaps millions of years from now?