1. Evolution: the process by which species of living things change over a period of time.

2. To scientists, a theory is a coherent explanation for a large number of facts and observations about the natural world.

3. example
Copernican theory- The sun is in the center of our solar system.

4. Evolution
The notion that species of living things slowly change as generation succeed is so well validated that it is no longer simply a theory, but a paradigm that shapes every aspect of the science of life.

5. Charles Darwin
In 1831, Charles Darwin sailed to the Galapagos Islands in the HMS Beagle.
Thirty years later he published his theory of evolution, unquestionable one of the most revolutionary ideas science has ever known.
Darwin is generally credited with the theory of evolution by natural selection.

6. Five year voyage of H.M.S. Beagle (1831-1836)

7. Darwinian fitness: ability to survive and reproduce in a particular environment

10. Darwin found many unique species on his voyage to the Galapagos
Break time
Darwin found many unique species on his voyage to the Galapagos

12. Natural selection
Natural selection is that the fittest survive and reproduce and therefore increase the fitness of the species.

13. Mutation = Raw material for evolutionary change

14. The story of the Giraffe

15. Natural selection
DARWIN'S FOUR POSTULATES of Natural Selection

16. Natural selection DARWIN'S FOUR POSTULATES of Natural Selection
individuals within species vary

17. Natural selection DARWIN'S FOUR POSTULATES of Natural Selection
individuals within species vary
some of these variations are passed on to offspring

18. Natural selection DARWIN'S FOUR POSTULATES of Natural Selection
individuals within species vary
some of these variations are passed on to offspring
more offspring are produced than can survive

19. Natural selection DARWIN'S FOUR POSTULATES of Natural Selection
individuals within species vary
some of these variations are passed on to offspring
more offspring are produced than can survive
individuals with the most favorable adaptations are more likely to survive and reproduce.

20. Natural Selection

22. Natural Selection

23. The Peppered Moth

24. The Peppered Moth
The peppered moth is found in England and usually lives on lichen-covered trees.

25. The Peppered Moth
The peppered moth is found in England and usually lives on lichen-covered trees.
Before the industrial revolution, there were many more light-colored moths compared to black ones.
They are both the same species, but just different colors.

26. The Peppered Moth
The peppered moth is found in England and usually lives on lichen-covered trees.
Before the industrial revolution, there were many more light-colored moths compared to black ones.
They are both the same species, but just different colors.
Light ones were well camouflaged on the lichen-covered trees, whereas the dark ones stand out.

27.                                                                
Dark moths on light colored bark are easy targets for hungry birds but are hidden on pollution darkened trees.   

28. Moth
During the industrial revolution, air pollution killed the lichens on the trees, resulting in bare, dark trees.
By the 1950s, the pepper moths were mostly dark colored.

29. Moth
In late 1950s a British physician and amateur moth collector, H.B.D. Kettlewell stated the HYPOTHESIS (just a guess) that the color of the moths protected them from insect-eating birds.

30. Moth
Before industrial revolution, dark-colored moths stood out against the light trees and were more likely to be eaten by birds, after industrial revolution, the reverse happened.

33. Basis for Evolution Changes very slowly.
adaptation: a trait that increases the fitness of an individual.

34. Basis for Evolution Changes very slowly.
adaptation: a trait that increases the fitness of an individual.
While some changes can be observed directly, much what we know about the history of life on earth comes from the fossil record.

35. Basis for Evolution Changes very slowly.
adaptation: a trait that increases the fitness of an individual.
While some changes can be observed directly, much what we know about the history of life on earth comes from the fossil record.
A fossil-is any trace of a long-dead organism.

36. Law of Superposition
In 1669, Nicolaus Steno proposed the Law of Superposition stating that successive layers of rock or soil were deposited on top of one another by wind or water.
This means that the lowest layers are the oldest, while the top layers are the most recent.
This law is still accepted today and allows scientists to give fossils a relative age.

37. Law of Superposition

38. Geological strata (Layers of rocks) contains an  evolutionary sequence of fossils

40. How we date rocks: Radioactive Dating
Uranium 238 is a naturally occurring isotope that decays to form lead.
It has a half life of 4.5 billion years.
The earth is 4.5 Billion years old.
Decay starts from the moment that uranium is incorporated into rock.
So, by measuring the relative proportion of uranium 238 and the lead that has formed we can tell how old a rock or layer of rock is.

41. Hominid Fossils

42. GRADUALISM
Living things change very slowly. GRADUALISM

43. Dino Fossil
206 million years old fossil

44. Palaeobiology

46. Maiasaura

47. All of these samples are evidence of past life

48. Carcharodon megalodon Tooth

50. PUNCTUATED EQUILIBRIUM
Sometimes species will remain the same for a long period of time and then change very quickly.
This is usually the result of some catastrophic disaster like an earthquake or volcano.

51. Dino’s Die because of Meteor impact

52. Geographic isolation
Geographic isolation prevents a mix of genes with the original species.

53. Geographic Isolation Example: Kodiak Brown Bears
This group of bears have evolved into a sub-species, that is different form all other grizzly bears.

54. An archipelago is a landform which consists of a chain or cluster of islands.

55. GALAPAGOS FINCHES

56. THE EVOLUTION OF BEAK SHAPE IN GALAPAGOS FINCHES
Darwin first thought about evolution while studying in the Galapagos
13 species of finches in the Galapagos islands
Islands are barriers that separate each group of the species- “Geographic Isolation”
size and shape of the beak has an important consequence for fitness. (What is Fitness?)

57. Darwin’s finches Medium Ground Finch Cactus Ground Finch
                      
Medium Ground Finch
Cactus Ground Finch
Medium Tree Finch
Warbler Finch

59. GALAPAGOS FINCHES Each species has a highly characteristic beak shape.
Darwin focused his study on the link between the shape of the beak, the food and the habitat of each species.
This research of his was to result in the theory of evolution and the 14 finches became "stars" in their own right.

65. The Case of the Galapagos Finches
All species of finch derive from the same original species.
The observation: despite their strong resemblance, each species of finch has a highly characteristic beak shape.
The evolutionary factors: geographic isolation, ecological environment, food sources, competition.

66. Adaptive radiation:
many species appear to be related to a single ancestral species.

67. Divergent Evolution

71. The Panda's Thumb A classic example of evolution.
The giant panda is a bear that adapted to eating bamboo.

72. The panda’s opposable thumb
Giant pandas have a thumb pad on the hand
This thumb pad is used by the panda to grasp bamboo shoots
It uses its thumb to hold and manipulate the bamboo while eating

73. The Panda has not always had this opposable thumb
The Panda has not always had this opposable thumb. Fossil evidence shows that this has evolved over thousands of years.

74. Comparing bones.

75. How Do We Know That Evolution Has Occurred?
The evidence for evolution has primarily come from four sources:
1.    the fossil record of change in earlier species

76. How Do We Know That Evolution Has Occurred?
The evidence for evolution has primarily come from four sources:
1.    the fossil record of change in earlier species
2.the chemical and structural similarities of related life forms

77. How Do We Know That Evolution Has Occurred?
The evidence for evolution has primarily come from four sources:
1.    the fossil record of change in earlier species
2.the chemical and structural similarities of related life forms
3.the recorded genetic changes in living organisms over many generations

78. How Do We Know That Evolution Has Occurred?
The evidence for evolution has primarily come from four sources:
1.    the fossil record of change in earlier species
2.the chemical and structural similarities of related life forms
3.the recorded genetic changes in living organisms over many generations
4.  the geographic distribution of related species

79. Homologous structures
Structures on different organisms are homologous when the have similar base structures but have different functions.

80. Homologous structures
Human Arm
Bat Wing
Whale Flipper

81. Analogous Structures Similar functions but NOT structurally related.
Insects are arthropods and birds are vertebrates.
The wing of a bird and the wing of a butterfly are examples of analogous structures.

82. Transition fossils