When considering classical mathematics, the Greeks must be a main focus of our attention. In fact, the primary reason for discussing earlier mathematics is to understand what the Greeks inherited and what they left to their posterity.
The organisms that engage in primary succession are known as pioneer species. Typical pioneer species include simple lichens, algae, and fungi. These simple organisms begin breaking down the resources in the environment and make it suitable for the later introduction of more complex species, such as vascular plants.
Ecologists (scientists who study the relationships of organisms with their living and nonliving environment) generally recognize two kinds of succession, primary succession and secondary succession. Primary succession takes place on an area that is originally completely empty of life. As an example, an area that has been covered by a flow of lava has, for a time, no life at all on it. Over a period of time, however, various kinds of organisms begin to grow in the area.