Is There a Limit to Evolution on Earth?

What are our limits to evolution? There are two theories concerning the growth of diversity amongst the planet. These 2 theories include diversity in an equilibrium or diversity that is rapidly expanding (occupying every possible niche, as well as, exploiting current ones in order to gain a better advantage). While the theory of equilibrium states that basically every niche has been occupied already and that in order for a new species to come on the scene, it must win out against a present species, this particular theory is not what we are concerned with in this blog. We are more so concerned with the expansion theory. In this theory, there is no noticeable (at least at the moment) ceiling for organisms diversifying or speciating in the world (meaning that more and more species can evolve and yet there still be more room on Earth). This could be a result of possible extinctions that have opened up the playing field OR that there is a constant arms race between members of the food chain -- or both! By arms race, I mean as the predators find ways of getting more energy, food, etc., the prey finds ways to survive while still be exploited by the predators. Many examples are available of this so called arms race, but nonetheless, when every avenue is exhausted to obtain energy to live, what is the last stronghold that organisms, possibly large or small, will try to take? Some scientists believe that if there is a limit to evolution and speciation is in fact, an expanding process, then individual organic molecules, such as carbon, might be the last frontier. This is a very mind opening thought! How long would this process take to get to such levels of energy scavenging? How densely populated will our earth be at this point? Will we even still exist by the time something like this can happen? It has yet to be seen, but you better believe, they are all possibilities!