My friends are geeky. There isn’t any getting around it, and I kind of like the fact.
I have listened, and even participated in several conversations that began “Who would win….” The answer is usually “Batman,” because even if he looses he will come back and win the second battle.
So when the question regarding world building, and specifically how two sentient species could coexist popped up I had no problem entering into this discussion. I’d already had this discussion on other occasions.
This question comes up a lot when dealing with worlds like TSR, LOTR, and others that have several species (elf, dwarf, human) that all live together. Some authors add in explanations of how they came about. Others simply make it an act of a god and leave it at that. The more scientific explanations usually come from Sci-fi sources such as Star Trek.
Star Trek 4 has to be one of the worst movies in the lot. (And I’m a major Trekkie. I still think it was pretty bad.) It did have one subject that I rather liked: humans assume we are the only intelligent race on earth, but have no common frame of reference to distinguish this as fact.
As an example, dolphins have been known to do things we recognize as intelligent or showing feeling. Whales have tried to rescue their calves. Dogs will rescue their owners. Several species of ape and birds are known to use tools. Is this intelligence? Do they feel emotion? Is it just instinct or something else? Can we really tell?
When discussing how and if two intelligent races can coexist on one planet we first have to determine what is intelligence and how do we measure it. For earth, and humans, we acknowledge humanity as intelligent because of how much we can adapt to the environment and the environment to us. We can build, create, and invent, while other species are still learning the value and use of tools.
If they did evolve, we may not even recognize their intelligence because their goals in life, their ambitions, and needs do not overlap ours enough to make it known. As an example take dolphins. They do not need homes, or jobs. They do not need money. They need fish and open waters. They do not compete for many of our resources, and likely never will since their sphere of influence is the ocean, while ours is mainly the land.
It isn’t inconceivable that these species could evolve to human like intelligence… if we let them. I think a big part of it is, evolution wise, that whichever species evolved first would have to get to a point where they did not feel threatened, and even helped the “lesser” species. If we continue to hunt apes and dolphins their evolution could end short in extinction.
In short… We really don’t know the possibilities. They are simply endless.