How to Read an Evolutionary TreeHominid "Family Tree": This evolutionary tree depicts lines of possible descent for hominids. In other words, it proposes relationships among species over time. All trees are hypotheses, and are based on comparison of living species, fossils, and genetic data.
Reading This Evolutionary Tree:
1. Dashed lines show how related species diverged from each other through a common ancestor.
2. Faded lines indicate very unclear origin or descent.
3. Branch points are called nodes. Nodes indicate a species that once lived, and was the common ancestor of two or more descendants.
4. Horizontal lines indicate time.
5. Orange vertical bars indicate how long a species is known, from fossils, to have existed.