It should be natural selection since there is no external influence implied. (like environment or genetic mutations.)
Rainwater picks up carbon dioxide from the air and as it percolates through the soil, which turns into a weak acid. This slowly dissolves out the limestone along the joints, bedding planes and fractures, some of which become enlarged enough to form caves.
Answer:Neurons are specialized to transmit information throughout the body. These highly specialized nerve cells are responsible for communicating information in both chemical and electrical forms.
Explanation:
Osmosis is the controlled movement of free water molecules though a selectively semi-permeable membrane from a region of high water concentration to a region of low water concentration. Using this definition osmosis will be the movement of water molecules.