Coal is formed when layers of plant matter accumulate at the bottom of a body of water and are protected from biodegradation and oxidization. Over time, the properties of the original material change.

Coal is formed when layers of plant matter accumulate at the bottom of a body of water and are protected from biodegradation and oxidization. Over time, the properties of the original material change. What evolutionary significance, if any, does this have? It is a form of fossil fuel that can be used for generating energy. It is a form of fossilized plant and can be used to study the plants that lived at the time. It does not have any evolutionary significance.