1. EVIDENCE OF EVOLUTION
CHAPTER 15-2

2. EVOLUTION DEFINED…
Evolution is a process of gradual modifications

3. EVOLUTION DEFINED…
Evolution is a process of gradual modifications Darwin called this descent with modification

4. Ancestor COMMON ANCESTOR Organism 1 Organism 2
Many animals and plants shared common ancestors and deviated from that common ancestor overtime.
Organism 1
Ancestor
Organism 2

6. 7 LINES OF EVIDENCE SUPPORTING THE THEORY OF EVOLUTION

7. 1. Paleontology Fossils provide geologic evidence of evolution
Fossils in older layers are more primitive than those in the upper layers

8. 1. Paleontology Fossils provide geologic evidence of evolution
Fossils in older layers are more primitive than those in the upper layers
Shows that life has become more complex.
Shows that life on earth has not always been the same

9. Transitional Species: Direct descendants of modern day species
Fossil record contains the intermediates
Descent with modification states that newer species are modified versions of older species

10. 2. VESTIGIAL STRUCTURES
Remnants of organs or structures that had a function in an early ancestor.

11. 2. VESTIGIAL STRUCTURES
Remnants of organs or structures that had a function in an early ancestor.
Shows that these organisms are descendants from organisms that used them.
Ex: Whale hind leg bones

12. 3. HOMOLOGOUS STRUCTURES
Body parts that are similar in structure, but may have different functions

13. 3. HOMOLOGOUS STRUCTURES
Body parts that are similar in structure, but may have different functions
Indicating at some point way in the past they did the same job and came from a common ancestor

14. FEATHERS

15. 4. ANALOGOUS STRUCTURES
Same functions but different development

16. 4. ANALOGOUS STRUCTURES Same functions but different development
ex. a butterfly wing and a bat wing
Indicates that populations evolve to be better suited to the environment

17. 5. Biogeography
Geographical distribution of living creatures.

18. 5. Biogeography Geographical distribution of living creatures.
Similar species are found in similar places showing common ancestry.
(divergent evolution)
Ex: marsupials in Australia

19. 6. Embryology
Some stages of embryo development of different organisms are similar
Shows common ancestry

20. 7. Biological Molecules Similar proteins means similar DNA
DNA  RNA Proteins
Similar proteins means similar DNA

21. 7. Biological Molecules Similar proteins means similar DNA
DNA  RNA Proteins
Similar proteins means similar DNA
The more similar proteins means they share a recent common ancestor

22. Whale Video
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