1. Mrs. Stewart Honors Biology Central Magnet School
Evidence of Evolution
Mrs. Stewart
Honors Biology
Central Magnet School

2. Standards: Objectives:
CLE Summarize the supporting evidence for the theory of evolution.
Objectives:
Differentiate between homologous and analogous structures and give examples of each
Define vestigial and give 2 examples of vestigial structures
Summarize the evidence of evolution for whales

3. Shoulder Partners

4. Descent with Modification
Over long periods of time, natural selection produces organisms with different structures, niches or occupy different habitats than their ancestors.
Each living species has descended, with changes, from other species over time.
Result: species today look/act different from their ancestors

5. Common Descent
Look back: Tigers, panthers and cheetahs all share a common ancestor
Look back further: you will find ancestors that these cats share with horses, dogs and bats.
Farther back: common ancestors of mammals, birds, alligators and fishes.
Logic: looking far enough back we should find the common ancestor for all living things

6. Common Descent

7. Tortoise
Explain to the Hare the meaning of the evolution theory: Common Descent w/ Modifications

8. Evidence of Evolution Homologous & Analogous Structures Fossil Records
Vestigial Structures
Evidence of Evolution
Comparative Embryology
Molecular Biology

9. Fossil Records Fossils - preserved remains of ancient organisms
Compare fossils from older layers and younger layers and show changes in species over time

10. Fossil Records
Compare fossils found around the world and we can infer when and where different organisms existed.
Fossils also provide evidence about the environment in which the organism existed and for which the organism adapted

11. Transitional Species
Fossil records show species which have features that are intermediate between those of hypothesized ancestors and later descendant species

12. Homologous vs. Analogous Structures
Homologous –structures that share the same basic structure but differ greatly in function
Analogous –structures that vary greatly in structure but share the same function

13. Homologous Body Structures

14. Hare
Explain to Tortoise what a Homologous Structure is.

15. Homologous Body Structures
Similar structures with different functions
Example: The limbs of reptiles, birds and mammals (arms, wings, legs and flippers) vary greatly in function but are all constructed from the same basic bones.

16. Analogous Structures Similar functions but different structures

17. Tortoise
Explain to Hare what an Analogous Structure is.

18. Vestigial Structures
organs/body parts that were once used, but by natural or artificial selection, are no longer necessary

19. Evidence of Evolution
Evidence of evolution on your own body

20. Vestigial Organs
Appendix

21. Vestigial Organs
Hip bone in a whale

22. Vestigial Organs
Tailbone in humans

23. Vestigial Organs
Plica Luminaris = Third Eyelid

24. Hare
Explain to Tortoise what a Vestigial Structure is.

25. Similarities in Embryology
The early stages, or embryos, of many animals with backbones are very similar.
Does this mean that a human embryo is ever identical to a fish, or a bird embryo? NO
But, many embryos look especially similar during early stages of development.

26. Fish Salamander Tortoise Chicken Pig Man

27. Comparative Embryology
What do these similarities mean?
The same groups of embryonic cells develop in the same order and in similar patterns to produce the tissues and organs of all vertebrates.

28. All animals go through this process
Its at the blastocoel step that we differ
Blastopore could become mouth or anus, etc.
All vertebrates share a common ancestor

29. Tortoise
Explain to Hare how comparative embryology shows evidence of common descent

30. The number of amino acids that differ from human hemoglobin
Molecular Biology
Using new technology, we can see how many DNA and RNA sequences organisms share in common
The more DNA sequences in common = the more closely related the organisms are on the Tree of Life
Amino acid sequences for major proteins used to determine how closely related different species are.
The number of amino acids that differ from human hemoglobin

31. Molecular Biology Amino Acid Similarities
Which two plants are the most closely related according to this chart?

32. Hare
Explain to Tortoise how to tell which organisms are most closely related using this chart.

33. The evolution of the whale
Evolution of Whales
The evolution of the whale

34. Assignment:
Evidence of evolution dry lab activity packet

35. Exit Ticket:
Question: Summarize the evidence to support that whales evolved from a land mammal.