No I don't believe aliens are involved in any of those things. I don't really think there is intelligent alien life out there, but since you just asked about aliens, intelligent or otherwise, I voted yes.
Intelligent life might be very rare. Here on this planet, multicellular organisms evolved into animals and plants.....and the concept of intelligent plants doesn't even make SENSE, seeing as how they been around for something like a billion years and never even developed a brain. Plants are as alien as it gets in our experience, and we treat them mostly as inanimate objects.
When it comes to intelligent life, you're asking not just for life to evolve, but for that life to develop in a way that is conducive to creating a brain of some kind, and also that the brain develops in such a way that it achieves "intelligence", as however you want to define that. I don't like the odds of that.
But if we're just talking about a lifeform, possibly developing like a plant or something even more bizarre that does not have a brain, I think that's likely.