Soil erodes, and plants and animals grow. Crystals grow, and sedimentary rocks form. Diverse bird forms show niche filling. Fossils show adaptation to change, or lack of adaptation. Convection currents influence weather.
Weather influences adaptations.
Physical and chemical changes occur throughout nature. A system is any collection of objects that influence each other. Each part of the system is truly understandable in the context of interaction between the members of that system. Traditionally, systems have been listed as being open, that is being influenced by things outside the system, and closed. An open system is actually a subsystem which is treated as a system for simplification.