1. Evidence for Evolution

2. 1. Fossil Record Age & Behavior patterns
Show changes in climate & geography

3. 1. Fossil Record

4. 1. Fossil Record Shows evolution & adaptation
Problems: Incomplete fossils & Imperfectly preserved

5. Similar Fossils in multiple layers
Fossil Record
Similar Fossils in multiple layers
Fossils that disappear

6. What similarities do you see among the forelimbs of these animals?
If you said “yes” then you just made a type of observation that scientists use to establish evolutionary relationships among organisms.

7. 2. Homologous structures – similar internal structure found in different groups of organisms

8. 2. Homologous structures
May or may NOT look the same on the outside
May have a different function
Shows common ancestor
Ex. forelimbs of vertebrates

9. What is a similar feature of these 2 organisms?

10. 3. Analogous Structures
Structures w/similar function, but different internal structure
Any body part that is similar in function but different in structure is an analogous structure.

11. Shows evolution
But NOT by a common ancestor
Ex: wings – bats, insects, & birds

12. 4. Vestigial Structures Structures/organs that are no longer used
May have been used by ancestor
Indicate a change has occurred

13. Examples
Ostrich wings
Human appendix
Cave fish eyes

14. 5. Embryology
Many different animals have the same organs when they are embryos
Ex: embryos of fish, reptiles, birds & mammals all have gills.
Suggests evolution from a common ancestor
zebrafish chicken dog human skunk

15. Evidence for Evolution
1) Fossil Record
2) Homologous Structures
3) Analogous Structures
4) Vestigial Structures
5) Embryology

16. Evidence for Evolution Lab

17. Evidence for Evolution
1) Fossil Record
2) Homologous Structures
3) Analogous Structures
4) Vestigial Structures
5) Embryology

18. 6. Genetic Comparisons
Shows evolutionary relationships using DNA sequences
Ex. DNA sequence for ATP is the same for all living organisms
Ex. Homologous structures require similar DNA

19. Which 2 species are most similar? Least similar?

20. Which 2 insects are most closely related? Most distantly related?B C D
Which 2 insects are most closely related?
Most distantly related?

21. Evolutionary Diagrams
Phylogenic trees and Cladograms –
Diagrams that shows evolutionary relationships of organisms based on similarities and differences in their physical or genetic characteristics.

22. Common Ancestor