Inside our own bodies there lives an entire world of living things. Inside just a single cell there exists an entire world as well.
To me, the general description of evolution just does not make sense if you factor in everything combined. One life form adapts to its surroundings.
On the Earth, everything has a purpose to promote healthy life and destroy unhealthy life. If you look at how bacteria for digestion, ants cleaning up dead insects and rotton fruits, birds canvasing the skies to clean up dead animals, worms to make soil better, trees to make oxygen and eat carbon, animals to breath oxygen and release carbon, if you don't believe a God created it all, then it atleast appears that such as within our own bodies there exists a world of life to keep us alive, that perhaps the planet or something else is a life and that's how there is such a diversity of life on this planet with a purpose.
Even if you don't believe in God, the current explanations for life on Earth are just as hard and don't answer all questions.