1. Evidence supporting Evolution

2. Six main lines of evidence that supports the theory of evolution
Fossil Evidence
Homologous Structures
Vestigial Structures
Geographic Distribution of organisms
Embryology
DNA Evidence

3. Fossils How Fossils Form
Fossils can be very large complete skeletons, or very small items such as a tooth
Most fossils form in sedimentary rock
The formation of fossils only occurs under certain conditions & therefore the fossil record is an incomplete record of life & evolution

4. Fossil Record
Fossil of a fish: perch

5. Formation of a Fossil
Water carries small rock particles to lakes and seas.
Dead organisms are buried by layers of sediment, which forms new rock.
The preserved remains may later be discovered and studied.

6. What we can conclude from the fossil record?
The fossil record provides evidence about the history of life on Earth.
It also shows how different groups of organisms have changed over time
99% of all living things that have lived on the Earth are now extinct

7. What the fossil record show us
Organisms that went Extinct
Example:
Ammonite

8. What the fossil record show us

9. What the fossil record show us
Example:
Dinosaur
tracks

10. What the fossil record show us
The fossil record shows us how animals have changed over time o Examples: Skulls of Australopithecus and Homo erectus

11. The fossil record shows us how animals have changed over time
Examples: Fossils of Skeletons of horse ancestors shows the evolution of the modern horse

12. Fossils of Skeletons of horse ancestors shows the evolution of the modern horse

13. Figure 25.1h Mammoth tusks

14. Figure 25.1c Petrified trees

15. Figure 25.1a Dinosaur National Monument

16. Figure 25.1d Leaf impression

18. Geographic Distribution of Organisms
The distribution of living things on the globe provides information about the past histories of both living things and the surface of the Earth.
Example: Fossils of marsupials found in the Antarctic as well as in South America and Australia

19. Geographic Distribution of Organisms
Closely related species tend to be found close together suggesting that they evolved in on place and then spread.

20. Homologous Structures
Traits that are similar in different species, share a common ancestor
Examples: arm in a human, flipper a seal, wing of a bat all have the same bone structures, but serve different functions
The species then adapted to a different niche

21. The bones in a bat's wing, human's arm, penguin's flipper are the same (homologous), but the function is different

22. What can we conclude from similarities in bone Structure?
Common Ancestors

26. Analogous Structures
Similar in function, differ in structure, not inherited from a COMMON, ancestor
For example, the wing of a bird and the wing of an insect are classified as being analogous structures since their structures are unrelated (next slide)
Evolved independently

28. Vestigial Structures
Structures that are inherited but no longer used by the organism
They are ancestrial remnants that once had a purpose, but now have no functional pupose
Example: Small hind leg bones (pelvis & femur) of a whale

29. Example: Our appendix has no functional purpose, but our herbivore ancestors used it to help them digest plant material

31. Embryology
Vertebrates embryos pass through a series of similar stages in early development.

32. Human
Chicken
Pig

33. Biochemical Evidence of Evolution
Similarities between living things:
All use DNA as their genetic material
All use the same 20 amino acids in their proteins
All use ATP to store chemical energy.
All do similar cellular respiration to access energy from food (chemical energy)

34. DNA Evidence
Comparing DNA sequences between living organism show close similarities between organisms of different species.

35. Example: Humans and chimpanzees have 95-99% identical DNA sequence
This suggests a recent common ancestor.

36. ALL LIVING THINGS USE DNA
Similarities between living things:
All use DNA as their genetic material
Suggesting common ancestry.

37. All proteins in living things are made of the same 20 amino
Similarities between living things:
All use the same 20 amino acids in their proteins
Suggesting common ancestry.

38. Similar Proteins in all vertebrates
All vertebrates, including fish, reptiles, amphibians, birds, mammals use the protein hemoglobin to transport oxygen in blood.
Suggesting common ancestry.

39. Similarities between living things:
D.5.2 Explain the biochemical evidence provided by the universality of DNA and protein structure for the common ancestry of living organism
Similarities between living things:
All use left, and not right-handed amino acids
Suggesting common ancestry.

40. ATP
All living things use the molecule Adenine Triphosphate for energy.
Suggesting common ancestry.