I made a pretty generalized argument, but the point is, what we observe as harmony in nature - the balance between predator and prey, the various species of animals and plants (and bacteria and viruses) living next to each other - is a dynamic process that involves lots of blood, death and starvation. The order in nature isn't negotiated - it's an aggregate of countless number of conflicts.
Related, recently on HN, "Trillions of Viruses Fall from the Sky Each Day": https://news.ycombinator.com/item?id=16839636. The money quote from the article is mentioned here: https://news.ycombinator.com/item?id=16840575.
"One study estimated that viruses in the ocean cause a trillion trillion infections every second, destroying some 20 percent of all bacterial cells in the sea daily."
That's nature's harmony at work.