I'm designing a world similar to Earth (liquid water, temperate climate, there is an atmosphere, oxygen and complex life everywhere).
The only big difference is that there is a giant (not glowing!) moon with an impossible orbit, and its shadow is always on the same area on the ground. So I basically have an area with good life conditions, but no sunlight (We can assume that some river will cross the dark area and that wind will bring oxygen in it from illuminated areas).
I'm aware that such an orbit is not realistic, let's ignore this point.
What would life (plants, animals) look like and evolve? Could light be used as another tool by evolution?
I though about mushrooms, and I looked for similar conditions that could exist in real life (caves?), but I didn't find anything that could be interesting for a story.