Healthier for who or what or to what end? Whatever changes (because of humans or otherwise), some individuals of a species may evolve to fit better to that... or they'll perish and something else will happen there. Worst case, it will go back to how things were 4 billion years ago.
>There is more competition so any organism (such as a disease-causing bacteria) is less able to cause a pandemic.
And humans are special why? Disease-causing is very human-centered... because of course we are special because God created us in his image. You may deny that because you "believe in evolution"... but I'm arguing is your beliefs make more sense if I go with the assumption that you belive in the Christian dogma and do not believe in evolution AT ALL. You may use your understanding of evolution to justify your Christian beliefs while simultaneously denying that you believe in Christianity... but from the outside, I see right through you.
If you believed that we are not special and that bacteria is running the world as much as we think we are, there is no need to favor humans over disease-causing bacteria.
>How this interplays with evolution is that humans are in the position of unintentionally changing the environment drastically so that many species are now 'unfit.'
>Conservation relies on an understanding of human power over the environment and a desire to maintain an environment that doesn't succumb to the same problems we see with monocultures.
If you believed in evolution, you'd see that humans are just as much part of nauture as anything else. It's your Christian dogma that leads you to believe that the world was created with a certain intent and humans are ruining it (by going against God's will, like Adam did with the fruit).
Again, in absence of Christian dogma, and with knowledge of evolution, you would not see the world as you do now.