1. Warm-Up: page 32 How is the evolution of earth’s surface related to the evolution of living organisms? Be very specific in your answer and use vocabulary 5pts
Date
Session #
Activity
Page #
1/13-14
Principles of Evolution Stations Review 30
Evidence of Evolution 31
1/15-16
Evidence of Evolution Notes 32
Genotype vs Phenotype
Quick Write 33
h/w: complete on p33 of your notebook
Complete phenotype and genotype compare and contrast activity

2. 8.L.4 Understand the evolution of organisms and landforms based on evidence, theories and processes that impact the earth over time. 8.L.4.1 Summarize the use of evidence drawn from geology, fossils, and comparative anatomy to form the basis for biological classification systems and the theory of evolution

3. TLW identify the evolutionary relationship between organisms by comparing and contrasting structures, DNA and embryology then summarize how evidence is used to support evolution in a quick write.

4. Contents, Covers and the stories they tell Part 1
Carefully examine the bone structures on Lab Sheet 1.
(Note: bones are not drawn to scale.)
All are forelimbs of mammals. Look for key structural features that give tell-tale clues about which mammal the bones are from.
Bone Set
Key Structural Features
Proposed Animal Source A B C D
Five separate digits or fingers; hand-like structure; long, thin upper and lower arm segments
Human E

5. MOLE
SEAL
ELEPHANT
OPOSSUM
WOLF
7 BAT

6. Evidence of Evolution p.32
Comparative Anatomy
Homologous structures (divergent evolution)
Analogous structures (convergent evolution)
Vestigial Structures
Embryological Similarities
Cellular/Molecular Similarities
Similar DNA
Similar Biochemistry
Fossils

7. Homologous Structures
Traits inherited by two different organisms from a common ancestor
Similar anatomy, different function

8. Example of Homology: the tetrapod limb
The tetrapod limb In an evolutionary tree, traits are passed from ancestor to decendent

9. The wing of a dragon fly and the wing of a butterfly are homologous – they were both inherited from an ancient flying insect

10. Not all homologous structures are obvious if they have been adapted for different roles. For example, the chomping front teeth of a beaver look quite different than the tusks of an elephant. Each is a modification of the basic incisor tooth structure

11. Homologous structures show that Divergent Evolution takes place
Divergent Evolution creates Homologous structures: A common ancestor evolves into new species, which continue to evolve and become less and less alike over time due to differences in their environments

13. Brown bears and polar bears illustrate divergent evolution
Brown bears and polar bears illustrate divergent evolution. Scientists think that a long time ago a group of brown bears became geographically separated from the rest. This isolated group acquired new characteristics, such as the ability to eat meat, blubber to keep warm in snowy weather, and a white coat for camouflage. They slowly evolved into polar bears.

14. So what about ANALOGOUS STRUCTURES?? Consider the following example…..
Thylacosmilus Smilodon

15. Both are extinct animals and both of them have saber-teeth…but are they homologous structures? (Consider that Australia had separated from the Supercontinent a loooooong time ago)

16. They are Analogous structures
They are Analogous structures! Similarity due to convergent evolution (evolved to the same environment) Not common ancestry CONVERGENT Evolution creates Analogous Structures: When two separate groups of animals evolve to have similar structures because they have evolved in a similar environment Similar function, different anatomy

17. How do analogous structures evolve?
Often, two species face a similar selection pressure. Natural selection may then shape both of them in similar ways – resulting in analogous structures…...like the saber teeth.

18. So there you have it….. HOMOLOGY vs ANALOGY
Similar due to inheritance Similar due to other factors

19. Apply your knowledge p32
For each of the 4 example3, write: Organisms’ names and structure we are comparing Are they homologous or analogous structures? In one sentence, explain your answer

20. 1. Sugar Glider & Flying Squirrel “cape”

21. Placental reproduction Marsupial reproduction
Squirrel
Glider
Placental reproduction
Marsupial reproduction
Large eyes
Fur

22. While sugar gliders (marsupials) superficially resemble the placental flying squirrels of North America, the ability to glide through the air evolved independently in these mammals.

23. 2. Shark and Dolphin body shape
Streamlined body
Triangular Dorsal Fin
Skeleton made of cartilage
Skeleton made of bone
Use gills to get oxygen from the water in which they swim
Go to the surface and breathe atmospheric air through their blowholes
Don’t nurse their young
Do nurse their young
Don’t have hair
Do have hair –they are born with hair around their “noses”
Propels through water in side-to-side motion
Propels through water in up and down movement

24. They have ANALAGOUS structures
Sharks are closely related to rays, and dolphins are closely related to other mammals. Streamlined bodies and fins are traits that dolphins and sharks evolved separately, both as adaptations from swimming.

25. 3. Leaves of oak trees and the leaves of gingko trees
Oak Leaves
Ginko Leaves
Photosynthesis
Cell walls
Multi lobed shape leaf
Single lobed shape leaf
Large leaf surface area

26. 4. Pointed Snout and Sharp Claws
Anteater
Echidna
Fur
Placental Mammal
Egg Laying Mammal
Eats from Anthills
Latin & South America
Australia
Long, Sticky Tongue

27. Vestigial structures/organs
Structures or organs that seem to serve no useful function. Vestigial organs are often homologous to organs that are useful in other species
For example: snakes have tiny pelvic bones and limb bones
eyes on cave salamanders (blind)
leg bones in whales
Organisms having vestigial structures probably share a common ancestry with organisms in which organisms in which the homologous structure is functional.

28. Hind limbs in Whales
Pelvis & Hind limbs in Snakes

29. Embryology Similar early development
Developmental similarities can be see in comparing the early embryos of many species

30. Embriological Evidence Similar early development
Embryos are very similar
Early in development

31. Cellular/Molecular Evidence
Related organisms have similar chemical processes, chemicals and proteins.
Examples:
photosynthesis,
hemoglobin in mammals vs hemocyanin in mollusks
DNA (gene codes)
Related organisms share large % of similar DNA sequences (lots of genes in common)

32. Fossil Evidence
Preserved remains of ancient organisms….these allow us to compare anatomies and trace change….how?

33. Fossils provide evidence of:
Other organisms that lived at the same time
Progression of life
Geological Events that changed the environment and changed selective pressures

35. Tape onto page 33

36.
Turn and talk to your partner for 30 seconds…you will summarize the evidence of evolution and how we use it

37. Quick Write page 33
Summarize 2 types of evidence we have learned and how it is used to classify organisms and support the theory of evolution