Humans as an Evolutionary Being + More?

I think that the main problem is that there is much less "survival of the fittest" then before. We have no predators to speak of (not any that really curb the population), and medical science saves millions of people that would normally have died and not produced offspring. This has led to the current population explosion, which is at the root of many of the human-based problems with the planet. I think that once humans do whatever it is we will do to wipe oruselves out and screw the planet up royally before/during that time, the world will go on, new life will evolve, and the planet will have been no better/worse off for having us onboard for awhile.