They learn about geologic time, fossils, ancestral relationships, cladograms, variation, natural selection, and extinction. As students proceed through the module they respond to on-line questions that are kept as a student journal and can be used for assessment. The biodiversity we see is a result of evolution. Evolution has occurred over geologic time.
Fossils provide the evidence for the history of life on Earth.
A fossil is any trace of an animal or plant that was once alive. Fossil evidence indicates that life has changed over time. Fossils help us to identify the relationships among groups of related organisms. Closely related organisms share features inherited from common ancestors. Scientists use diagrams called cladograms to illustrate evolutionary relationships.