1. Homology, Biogeography & the Fossil Record
Evidence of Darwin’s Theories
* As we go through this Powerpoint, record some key points. You will need to create a set of notes for this section (pages in your text)

2. Homology
Similarities in traits resulting from a common ancestor

3. Anatomical Homologies
Physical features (ex. Mammalian forelimbs)
Vestigial organs: remnants of structures no longer of use (ex. Tailbone, appendix)

4. Embryological Homologies
Comparison of early stages of embryo development
Ex. Pharyngeal (throat) pouches  develop into gills (fish) or ear parts (human)

6. Greater similarities in protein structure = greater evolutionary link
Molecular Homologies
All living things use DNA & RNA for genetic code
Greater similarities in protein structure = greater evolutionary link

7. Biogeography
Endemic species are those that are found only in specific geographic areas (ex. Australia, Galapagos Islands)
Provides evidence for reproductive isolation leading to speciation

9. Fossil Record
Evolutionary transitions have left “signs” in the fossil record
Ex. Extinct whales with 4 limbs (shows sea mammals probably evolved from terrestrial ancestors)
Ex. Link between dinosaurs & birds (archaeopteryx)

10. Now it’s your turn 
Organize your own set of notes for this section (pages )
Include key terms as well as examples that support each term
Key Terms:
- homology/homologous - endemic
- vestigial organ - fossil record
- comparative embryology - transitional fossil
- molecular homologies - biogeography
Your notes will be checked next class & included as a part of your Learning Log/Notes for this Module.