1. Evolution Notes
Evolution - process in which modern organisms have descended from ancient organisms; change in a species over time

2. Evolution of the Horse
Note how the horse gradually lost toes and increased in size over time.

3. Supporting Evidence for Evolution
A. Age of the Earth: 4.5 BILLION Years old

4. B. Fossil Evidence
Fossil - preserved remains or traces of organisms (plants, animals, bacteria, etc.)
Fossils can be found in sedimentary rocks
The fossil record is the best evidence that evolution occurs

6. Youngest Complex Organism
Oldest
Simpler organisms

7. C. Comparative Anatomy
Anatomy - relating to the structures of the body
Comparative Anatomy is the study of differences and similarities in the anatomy of organisms
Homologous Structures – similar structures with different functions (whale flipper, human arm, bat wing)

10. Vestigial Structures – structures that were once functional but no longer are

11. The human appendix, a vestigial structure.

12. D. Comparative Embryology – shows common ancestry among organisms when comparing embryos
Embryo - an organism in early stages of growth and development prior to birth

14. very difficult to distinguish an early embryo of a fish, rabbit and a gorilla. All have tails and gill slits.

16. E. Comparative Cytology
Cytology - the study of cell structures and their functions

17. F. Comparative Biochemistry
Biochemistry - the study of chemical processes of living organisms
Biochemical evidence – the closer the relationship between organisms, the greater the similarity of their chemicals (DNA, proteins) – Humans can use insulin from sheep and pigs!!