The Earth's geologic time scale is primarily broken down into different periods based on:
A. Based on evolutionary trees and changes in species
The geologic time scale reflects the history of the Earth and is structured around significant events in Earth's history, including the emergence and evolution of different species, major geological and climatic changes, and mass extinction events. While mass extinctions do play a role in marking boundaries between certain periods, the overall framework primarily relates to the evolution of life forms and changes in biodiversity over time.
1 answer