2. EVIDENCE OF EVOLUTION Structural, Embryological, and Biochemical Evidence

3. COMPARATIVE ANATOMY Definition: study of structural similarities and differences among living things Importance—presence of similarities provides evidence for evolutionary relationships between species

4. ANALAGOUS STRUCTURES Definition: have the same function but different origins and composition CANNOT be used for classification Examples: wings of fly/wings of bird Rhinoceros horn/deer antlers

5. HOMOLOGOUS STRUCTURES Definition: structures with the same basic structure and evolutionary origin DO NOT share the same basic function DO show indications of common ancestry

6. EXAMPLES

7. VESTIGIAL STRUCTURES Definition: remains of structures that were functional in ancestral forms Reduced in size and serve little or no function in modern organisms

8. EXAMPLES Wisdom Teeth Appendix Coccyx Bone Ear/Nose Muscles Hind leg bones of python and whales

9. COMPARATIVE EMBRYOLOGY Early embryos of various organisms demonstrate evolutionary relationships As development proceeds, the traits of each species become more evident

10. COMPARATIVE BIOCHEMISTRY Similarities in DNA, hormones, and enzymes demonstrate a close relationship among various life forms Examples: