Story of Earth's History
Geologists divide the Earth into geologic periods, and while these are useful as a common language for all scientists, in reality they are man-constructed. Most geologic periods are demarcated because they indicate the beginning/ending of well-known fossils, or mark catastrophic events.
Another person could look at Earth's history and make different divisions. For example, these geologic periods may not correlate well with the origin and extinction of plant species. The attempt for this site, and specifically this section, is not to try to recreate the Geological Timescale.
In order to make geologic information more digestible, this section was created to bracket the major changes in Earth's history, with a focus on plant (and non-animal) evolution. Due to the close link between plants and the environment, you may find these divisions are more easily understandable.
Each narrative is successive to the next, and marks a major period in Earth's history that usually spans several Geologic Periods. Below you find the story of the Earth outlined on this site:
- History of early Earth (4,600–2,500 million years ago)
- Oxygen changes the world (2,500–635 million years ago)
- Life moves onto the land (635–425 million years ago)
- Origin of the first marsh-like environments (425–390 million years ago)
- Evolution of trees and early forests (390–350 million years ago):
- Dominance of swamps on Earth (350–300 million years ago): Domination of scale trees
- Largest extinction event in Earth's history (300–230 million years ago): Diversification of plants with seeds
- Dominance of the cone-bearing plants (230–145 million years ago)
- Origin of flowering plants (145–66 million years ago)
- Diversification of flowering plants (66 million years ago – present)