1. Evidence for Evolution

2. Major Evidence for Evolution
Fossil record
Homologous structures
Vestigial structures
Embryological development
Biochemical/ Molecular evidence (DNA)

3. Theory of Evolution By Natural Selection
In each generation of a species, individuals have slight differences.
Sometimes these variations make an individual more successful in its environment

4. (more food, live longer, reproduce more, attract better mates)
(more food, live longer, reproduce more, attract better mates). That individual may then reproduce and pass this variation on to its offspring.
Then the individual may reproduce and pass this variation on to its offspring.

5. Variations in individuals are controlled by genes. (Found in your DNA)
Natural Selection
Variations in individuals are controlled by genes. (Found in your DNA)
Individuals have no control over what variations they will have.

6. Useful variations are NOT ALWAYS passed on.
Variations that are NOT useful may also be passed on.

7. How did the variations come about?
Mutations!!!
What are Mutations?

8. 5. Molecular/Biochemical Evidence
DNA used to translate nucleotide sequences into amino acid is essentially the same in all organisms
Proteins in all organisms are composed of the same set of 20 amino acids
Powerful argument in favor of the common descent of the most diverse organisms.

9. Universal Code

10. Biochemical Compound Ex
DNA
Cyt C
20 amino acids
Some enzymes

11. Molecular/Biochemical Evidence
Cytochrome c
An ancient protein common to all aerobic (oxygen breathing) organisms
Amino acid sequence to make cytochrome c differs increasingly the more distantly related two organisms are (very similar amino acid sequence = closely related)
The cytochrome c of humans and chimpanzees is identical

13. Bill Nye: http://www. youtube. com/watch

14. 1. Fossil Record What does the Fossil Record tell us about organisms?
Looks (size, shape, etc.)
Where or how they lived
What other organisms they lived with

15. What time period they lived in (based on location in rock layers)
What order living things came in (based on location in rock layers)
Transitional forms
Organisms that were intermediate (between) two other major organisms

16. Example: Horse

18. Homologous Structures-bodily structures that are similar in structure, but different in function, due to sharing a common ancestor

19. 2. Homologous Structures

20. Homologous Structures

21. Analogous Structures
Analogous structures- bodily structures that are similar in function, but not in structure. NOT EVIDENCE OF COMMON ANCESTRY.
Example: wings of a bee and wings of a bird

23. 3. Vestigial Structures
Structures that serve no function but useful structures in earlier ancestors
Examples: Ear muscles
Human tailbone
Appendix

26. Vestigial Organs

27. 4. Embryological Development
Embryo- fertilized egg that will/is in the process of growing into a new individual
Closely related organisms go through similar developmental stages early in development
All vertebrates have gill pouches sometime during their early development