Upon completing this chapter, the student should be able to:

1. Discuss what changes emerge in the fossil record beginning about 2.7 million years ago.
2. Explain who the robust hominins were and how they were different from other Plio-Pleistocene hominin forms.
3. Explain who are the two gracile hominins and discuss their relation to later forms.
4. Explain what major changes happened in the human lineage about 2 million years ago, and how humans of this time period lived.