What evidence do scientists use to place events on this time line?

Scientists use various types of evidence to place events on a timeline, including radiometric dating techniques to determine the age of rocks and fossils. Stratigraphy, or the study of rock layers, helps establish the relative timing of events based on the sequence of sediment deposition. Fossil records provide insights into the evolution and extinction of species over time. Additionally, historical records and geological evidence, such as volcanic activity or ice core samples, contribute to a more comprehensive understanding of Earth's timeline.