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Evolution. Slide 1 - Evolution Change in species over.

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Presentation on theme: "Evolution. Slide 1 - Evolution Change in species over."— Presentation transcript:

1 Evolution

2 Slide 1 - Evolution Change in species over.

3 Slide 2 People used to believe: Species are designed by a divine creator (aka god) and are fixed/unchanging and perfect. False belief Earth is only 6000 years old. Earth is actually 4.5 Billion Years Old.

4 Slide 3 Charles Darwin and Evolution s

5 Slide 4 - Darwin’s Voyage 1831 at age 22 Darwin took a job as a naturalist on the English ship HMS Beagle.

6 Slide 5 - Darwin’s voyage on the Beagle

7 Slide 6 - Galapagos Islands Species were unique but similar to species elsewhere.

8 Slide 7 - Galapagos Tortoise

9 Slide 8 - Galapagos Iguana

10 Slide 9 - Galapagos Finches

11 Slide 10 - Species Similar traits and can mate and produce fertile offspring. But species within a population are different in some way.

12 Slide 11 Natural Selection What causes evolution!

13 Slide 12 - Peppered Moths Birds eat peppered moths! What moth has the advantage? What moth population will be larger?

14 Slide 13 - Industrial Revolution Covered trees and buildings with soot making them dark. Now which population is favorable? Dark or white?

15 Slide 14 - Evidence of Evolution  Fossils  Adaptations  Anatomy  Embryology  Biochemistry

16 Slide 15 - Fossils Showed that whale ancestors once lived on land.

17 Slide 16 - Adaptations Any variation that aids an organisms chances for survival. Structural Physiological Evolves very SLOWLY Evolves RAPIDLY

18 Slide 17 - Structural Adaptations  Mimicry  Camouflage

19 Slide 18 - Mimicry Mimic = to copy someone When one species resembles another species.

20 Slide 19 - Camouflage Matching in color with surroundings!

21 Slide 20 - Anatomy  Homologous Structures  Analogous Structures  Vestigial Structures

22 Slide 21 - Homologous Structures Homo = Same Same structures between species. Come from common ancestor!

23 Slide 22 - Analogous Structures Similar in function but not from common ancestor (e.g. Do bugs’ wings have bones like birds? No).

24 Slide 23 Homology Versus Analogy

25 Slide 24 - Vestigial Structure A body structure in a present-day organism that no longer serves its original purpose, but was probably useful to an ancestor.

26 Slide 25 - Stop and Think! What’s a vestigial organ in humans?

27 Slide 26 Vestigial Structure Examples: Mole Rat Ostrich

28 Slide 27 - Embryo

29 Slide 28 - Embryology Embryos have same structure among different species.

30 Slide 29 - Can you tell which will become a chicken? Cat? Bat? Snake? Human? Possum?

31 Slide 30 - How about now?

32 Slide 31 - Now??

33

34 Slide 33 - Biochemistry Some organisms have similar DNA sequences.

35 Slide 34 - For Example: Versus Chimpanzee Gorilla

36 Slide 35 - For Example: Versus Chimpanzee Rose Bush

37 History of Earth

38 Slide 38 - Geologic Time Scale Sequence of events from Earth’s birth to present-day (now).  Four main eras: 1. Precambrian (Earth Born) – First life evolved 2. Paleozoic – Plants evolved. 3. Mesozoic – Dinosaurs evolved 4. Cenozoic (Present – day) – Humans evolved

39 Slide 39 - When Earth was born No life existed. SurfaceSo hot all of Earth was melted rock! AtmosphereNo O2 because no plants existed yet! Only gasses from outgassing (Volcanoes erupting). OceansNo liquid water. Too hot! Everything was Water vapor.

40 Slide 40 -Where did O2 come from? Photosynthesis from plants!

41 Slide 41 - Rocks Where fossils are found!

42 Slide 42 - Fossil Anything left from a living organism.

43 Slide 43 - Types of fossils Petrified Fossil Casts Imprint

44 Amber-Preserved Ice - Preserved

45 Slide 45 - Fast Fact! About 99% of species that have lived on Earth are extinct.

46 Slide 46 - How old are fossils? Relative Dating  Fossils found in layers closer to the surface are younger than the deeper layers. Radiometric Dating  Measuring how much of an element is still present in a fossil, using the half life.

47 Slide 47 - Half Life Amount of time it takes for a radioactive element to decrease by half.

48 Slide 48 - Paleontologist Person who studies fossils.  Size of Animal  How they moved  What they ate.  What climate they lived in.  When organisms lived.

49 Slide 49 - Plate Tectonics Crust floats on the mantle which is composed of molten (melted) rock. Crust is divided into plates! Constantly moving (1-10 cm/year)

50 Slide 50 - Pangaea “All Land” All continents were once joined together.

51 Slide 51 - Pangaea Separated Laurasia and Gondwana

52 Slide 52 - Earth Today As continents moved species became isolated and started to evolve differently.

53 Slide 53 - Stop and Think Someone find a fossil of a polar bear that lived a billion years ago in Hawaii. What was the latitude of Hawaii a billion years ago?

54 Slide 54 - Australia Since it is so isolated from any other land, it has very unique species.

55 Slide 55 - Fossil Record Ordered levels of fossils in rock. Indicates that organism have evolved in sequence.

56 History of Life

57 Slide 57 - Overview  Small Organisms = Bacteria (microscopic)  Large Organisms = Non-microscopic (flies, humans, etc.)

58 Slide 58 Spontaneous Generation (SG) False idea that non-living things can produce life. Life “spontaneously” appears.

59 Slide 59 - Francisco Redi Proved Spontaneous Generation was wrong with a fly experiment.

60 Slide 60 – Redi’s Fly Experiment

61 Slide 61 - Louis Pasteur Disapproved microscopic organisms spontaneously appear.

62 Slide 62 - Before the Microscope People believed that bacteria was generated from a “vital” force in the air.

63 Slide 63 - Pasteur’s Experiment Bacteria create bacteria!

64 Slide 64 - Biogenesis Living organisms come from other living organisms.

65 Slide 65 - So where did the first life come from?

66 Slide 66 - Biomolecules Bio = Life Molecules made by living things!  Proteins (Muscles and Bone)  Carbohydrates (Sugar)  Nucleic Acids (DNA and RNA)  Lipids (Fat)

67 Slide 67 - Alexander Oparin’s Hypothesis How Biomolecules formed. Lightning hit the atmosphere of early earth (ammonia, water vapor, methane, hydrogen gas) and caused amino acids to form.

68 Slide 68 - Stanley Miller and Harold Urey Tested Oparin’s Hypothesis and found that it worked!

69 Speciation

70 Slide 70 - Speciation: When a species changes so much it evolves into a new species.

71 Slide 71 - Gene Pool: All the alleles in a population.

72 Slide 72 - Allelic Frequency The Percentage of any specific allele in the gene pool. Allele# of Alleles in Population Allelic Frequency R55/20 = ¼ = 25% r1515/20 = ¾ = 75% Total Alleles in population = 20

73 Slide 73 - Genetic Equilibrium When % of alleles does not change. Population is NOT evolving! Allele Evolving? R25%27% r75%73%

74 Slide 74 - What Changes Genetic Equilibrium?  Mutation  Genetic Drift  Migration

75 Slide 75 - Mutation Changes in DNA sequence. DNA Sequence: A-T-T-G-A-G-C Mutated DNA Sequence : A-A-T-G-A-G-C

76 Slide 76 - Genetic Drift: Change in gene pool by chance events. Affects small populations!

77 Slide 77 - Gene Flow Movement of genes In and out of a Population.

78 Slide 78 - Species Organisms that can can mate and produce fertile offspring.

79 Slide 79 - What can prevent mating? Geographic Isolation Reproductive Isolation Polyploidy

80 Slide 80 - Geographic Isolation: When a physical barrier divides a population.

81 Slide 81 - Example: Marsupials in Australia

82 Slide 82 - Reproductive Isolation

83 Slide 83 - Polyploid Abnormal Chromosomes E.g. Down Syndrome Reproductive Cell Gametes Zygote

84 Slide 84 - Rates of Speciation  Gradualism  Punctuated Equilibrium

85 Slide 85 - Gradualism: Species evolve gradually.

86 Slide 86 - Punctuated Equilibrium: Species evolve in quick bursts followed by stable periods!

87 Slide 87 - Patterns of Evolution Divergent Evolution Convergent Evolution

88 Slide 88 - Divergent Evolution: Evolution in which species diverge from an ancestor.

89 Slide 89 - Convergent Evolution: When organisms evolve similar traits but did not come from the same ancestor.

90 Slide 90 - Natural Selection Mechanism for change in populations!

91 Slide – 91 Natural Selection Cont. Traits vary in populations!

92 Slide Types of Natural Selection  Stabilizing Selection  Directional Selection  Disruptive Selection

93 Slide 93 - Stabilizing Selection: Individuals with average traits tend to survive. X-Axis Body Size Pop. Size Y-Axis

94 Slide 94 - Directional Selection Individuals with one of the extreme variations of a trait tend to survive. Beak Size

95 Slide 95 - Disruptive Selection: Individuals with either extreme of a trait’s variation tend to survive. Limpet Color

96 Slide 96 - Population Members of the same species that live in the same area. Populations not individuals evolve!


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