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.
In primary succession, bare rock or sand is the substrate upon which the pioneer species act. Primary succession occurs in places that are the result of lava flows or where glaciers have retreated. Soil is not yet present, so no plants or animals can survive in such a region.Pioneer species are the lichens and moss.