[Free Registration/Login may be required to access all resource tools.] Describes relationship between evolution and the geologic time scale.

Find out how fossil evidence has been the major link to learning about Earth's geologic history. See several illustrated interpretations of a geologic time scale in this online biology textbook.

Through informational text, interactive activities, animations, and video clips, students investigate evolutionary biology.

[Free Registration/Login may be required to access all resource tools.] This comprehensive lesson by CK-12 explains how scientists learn about the past by examining and dating fossils.

[Free Registration/Login may be required to access all resource tools.] Describes how scientists learn about the past by examining and dating fossils.

This in-depth article illustrates the concept of geologic time, and helps the learner understand why fossils are rare.

This comprehensive study guide covers the main terms and concepts needed for a unit on the evolution of multicellular life.

[Free Registration/Login may be required to access all resource tools.] For life to evolve from simple single-celled organisms to many millions of species of prokaryotic species to simple eukaryotic species to all the protists, fungi,...

To describe the diversity of unicellular organisms which arose over 2 billion years of evolution.