1. Review of Natural Selection & Darwin
5:05 – 15:35
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2. Evidence for Evolution
5-3

3. Homologous Structures
Structures that have similar arrangements, but different functions.
Suggests that some vertebrates descended from a common ancestor.
Ex. Forelimbs of whales vs. humans
Comparative anatomy or morphology= the study of structures to determine the development and relationship amongst species.

4. Homologous Structures

5. Analogous Structures
Structures that did not evolve together but have similar function.
Ex. Bird wing vs. butterfly wing.

7. Vestigial Structures
Structures many different organisms have, yet many don’t need or use.
Examples:
Ear-wiggling muscles
Appendix
Wisdom teeth
Coccyx (tailbone) in humans

8. Vestigial Structures

9. Embryology
Similarities appear in early embryos of vertebrates (animals with backbones).
Gil Slits Gil Slits
FISH REPTILE BIRD HUMAN

10. Biochemical Similarities
Amino Acid sequences of certain proteins help show how related different species are.
Ex. In the protein cytochrome-c, all 104 amino acids are the same between humans and chimpanzees.

11. Fossil Evidence
Many fossils show differences in organisms whose species still exists today.
Note: Fossils underwent bursts of change in brief periods of time (punctuated equilibrium). Overall, scarce evidence of gradual evolution.
Tropical plant fossil found in a mine in Illinois.

12. Summary Evidences for Evolution
Homologous Structures
Vestigial Structures
Embryology
Biochemical Similarities
Fossil evidence (transition fossils, though relatively few)