Homologous Structures and Evolutionary Relationships

1. What else shows that these two organisms might have an evolutionary relationship? ….

2. Human Arm As we go through the slides, color and label the bones with the class. You will need a red, green blue, orange, yellow and purple coloring thing. Humerus Radius Ulna Carpals Metacarpals Phalanges

3. 39L: Color and Label Homologous Structures Human Arm Humerus Humerus

4. Human Arm Humerus Humerus Ulna Ulna

5. Human Arm Humerus Humerus Radius Radius Ulna Ulna

6. Human Arm Humerus Humerus Radius Radius Ulna Ulna Carpals Carpals

7. Human Arm Humerus Humerus Radius Radius Ulna Ulna Carpals Carpals Metacarpals Metacarpals

8. Human Arm Humerus Humerus Radius Radius Ulna Ulna Carpals Carpals Metacarpals Metacarpals Phalanges Phalanges

9. What do these structures look like in other organisms? Pg. 39 L Round 1: Choose two: Lizard, whale, or cat • Color the structures in according to human arm example • Share with your group...What patterns do you see? Round 2: Choose two: Crocodile, bird, or bat • Color the structures in according to human arm example • Share with your group...What patterns do you see?

10. 40L Procedure: Color each of the same bones in the elephant and rat skeleton the same color. For example: color the femur of the elephant and the femur of the rat red. You do not have to do both the right and left of each bone.

11. Title: Reflection Questions pg40R Write your answers on page 40R in complete sentences, you don’t need to write the questions. • Were the bones with the same name in similar places on both the elephant and rat skeleton? Give an example. • Did either the rat or elephant skeleton seem to have extra bones? Explain. • Write a statement comparing the likeness of the rat and elephant skeleton. • Could you infer that the elephant and rat once had a common ancestor based on their skeletons? Why or why not?

12. Homologous Structures 39R • Homo- means the same • -logous means information • Share a relatively recent ancestor

13. Homologous Structures 39R Homologous structures are formed in similar ways during embryonic development and share like arrangements, however they can have different forms and functions.

14. What set shows a closer evolutionary relationship?

15. Analogous Structures: 39R Some apparently unrelated animals have organs with similar functions, yet are very different in structure and form, and do not come from the same embryological tissues. These structures are called analogous structures.

16. Homologous and Analogous module: https://evolution.berkeley.edu/evolibrary/article/0_0_0/similarity_ms_01

17. Homologous and Analogous module: https://evolution.berkeley.edu/evolibrary/article/0_0_0/similarity_ms_01 Discuss the following questions with your partner: • What is the difference between homology and analogy. • How are tetrapod limbs similar to each other? • Give four examples of homologous tetrapod limbs. • Give an example of a homologous structure in insects. • What can happen to homologous structures of different species over time? • Why are tetrapod and octopus limbs not homologous?

18. Homologous and Analogous module: https://evolution.berkeley.edu/evolibrary/article/0_0_0/similarity_ms_01 Be ready to discuss: • What is the difference between homology and analogy.

19. Stop Starting the following next class (Tuesday/Wed)

20. Homologous and Analogous module: https://evolution.berkeley.edu/evolibrary/article/0_0_0/similarity_ms_01 Be ready to discuss: • What is the difference between homology and analogy. homology- traits inherited by two different organisms from a common ancestry analogy- similarity due to convergent evolution, not common ancestry

21. Homologous and Analogous module: https://evolution.berkeley.edu/evolibrary/article/0_0_0/similarity_ms_01 2. How are tetrapod limbs similar to each other?

22. Homologous and Analogous module: https://evolution.berkeley.edu/evolibrary/article/0_0_0/similarity_ms_01 2. How are tetrapod limbs similar to each other? • all built from many individual bones • they are all spin-offs of the same basic bone layout: one long bone attached two two other bones (radius and ulna), with a branching series of smaller bones (carpals, metacarpals and phalanges) on the end.

23. Homologous and Analogous module: https://evolution.berkeley.edu/evolibrary/article/0_0_0/similarity_ms_01 3. Give four examples of homologous tetrapod limbs.

24. Homologous and Analogous module: https://evolution.berkeley.edu/evolibrary/article/0_0_0/similarity_ms_01 3. Give four examples of homologous tetrapod limbs. Human Bird Whale Lizard

25. Homologous and Analogous module: https://evolution.berkeley.edu/evolibrary/article/0_0_0/similarity_ms_01 4. Give an example of a homologous structure in insects.

26. Homologous and Analogous module: https://evolution.berkeley.edu/evolibrary/article/0_0_0/similarity_ms_01 5. What can happen to homologous structures of different species over time? 6. Why are tetrapod and octopus limbs not homologous?

27. What is an evolutionary tree? Tetrapod lineage (animals with four legs)

28. What is an evolutionary tree? 85 R Tetrapod lineage (animals with four legs) • In an evolutionary tree, • traits are passed from ancestor to descendant