CK-12 Foundation
Ck 12: Biology: History of Life
[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.
CK-12 Foundation
Ck 12: Biology: History of Life
[Free Registration/Login may be required to access all resource tools.] Describes how scientists learn about the past by examining and dating fossils.
Open Curriculum
Open Curriculum: Studying the History of Life
This in-depth article illustrates the concept of geologic time, and helps the learner understand why fossils are rare.
CK-12 Foundation
Ck 12: Biology: Evolution of Multicellular Life Study Guide
This comprehensive study guide covers the main terms and concepts needed for a unit on the evolution of multicellular life.
CK-12 Foundation
Ck 12: Life Science: Timeline of Evolution
[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,...
Open Curriculum
Open Curriculum: Multicellular Life
To describe the diversity of unicellular organisms which arose over 2 billion years of evolution.