A moss begins to grow on a rock in an area that was previously uninhabited by life. This is an example of a .

primary ecological succession

Explanation:

Primary ecological succession: This occurs when a certain or some organisms dominate an area that was uninhabited of life. This may happen after a natural disaster that leaves the land barren. The presence of these organisms on the barren land will help the soil occupied to gain nutrients which will eventually allow some other plants to grow on it. The growth of plants will later invite insects and insects may invite animals.