1. Bell Work
Pick up today’s note page
Define evolution

2. Introduction to Evolution and the Origin of Life
Mrs. Stewart
Biology
Stewarts Creek High School

3. Standards:
CCSS ELA
I can trace the historical development of the theory of evolution
I can summarize the evidence for the theory of evolution
CCSS ELA
I can critique and evaluate competing evolutionary arguments based on scientific knowledge, empirical evidence and logical arguments regarding relevant factors.

4. Can You… Define evolution
Differentiate between biogenesis and spontaneous generation
Differentiate between Charles Darwin and Jean-Baptiste Lamarck
Explain the idea of “natural selection” and determine “fittest”

5. Choose… But choose wisely.
Decide which partner is the bird and which is the cat.

6. Scientific Theory
Theory - a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment.

7. How did it all start? Abiogenesis:
The process by which life arises from non- living matter, such as organic compounds
Happened on earth approx billion years ago in the ocean
Enough organic compounds bound together and were able to conduct energy processes more efficiently until life was created

8. Early Beliefs of How New Life Formed
Abiogenesis / Spontaneous Generation: Living organisms could arise from nonliving matter
Example: Cheese wrapped in a rag and left in a corner would produce mice
Disproven by Redi and Pasteur
Biogenesis:
All living things come from other living things

9. Miller/Urey Stanley Miller and Harold Urey (1950s)
simulated early earth conditions in the lab and created a “spark”
created amino acids

10. Archaebacteria
The earth’s earliest life forms were prokaryotes

11. Endosymbiosis Where/how did mitochondria get their own DNA?
How did chloroplasts become so specialized?
Theory of Endosymbiosis:
Aerobic prokaryotes were engulfed by eukaryotic cells evolved into mitochondria (which perform aerobic respiration)
Photosynthetic prokaryotes were engulfed by plant cells and evolved into chloroplasts (where photosynthesis occurs)

12. How did we go from bacteria to mammals? Evolution

13. What is Evolution?
Evolution of Dance

14. Evolution The process of change in all forms of life over generations
In general: how new species develop from preexisting species

15. What does it explain? Does not attempt to explain the origin of life
Does explain how the most basic early life forms became the complex ecosystem we know today

16. Cats
Define evolution for your bird

17. Jean-Baptiste Lamarck
French Naturalist
1809
Lamarck’s Hypothesis: by selective use or disuse of organs, organisms acquire or lose certain traits. These traits could then be passed on to their offspring.
Lamarck believed over time, this process led to change in a species.

18. Lamarck’s Hypothesis
1. Tendency toward perfection - All organisms have an innate tendency toward complexity and perfection, so they are continually changing to be more successful in their environment 2. Use and disuse - Organisms can alter their bodies/organs by use or disuse 3. Inheritance of acquired traits - Organisms can pass on those altered body parts/organs to the offspring

19. Lamarck’s Hypothesis

20. Birds
What did Lamarck get right?

21. Cats
What did Lamarck get wrong?

22. Lamarck the Loser First to develop a hypothesis of evolution
First to realize organisms adapt to their environment
But, Behavior has no effect on inheritable characteristics

23. Charles Darwin
1809 – 1882
Naturalist – study of nature and the natural world
Sailed on the HMS Beagle in 1831
Every time the ship docked, Darwin went ashore to collect plant and animal specimens

24. Darwin’s observations piqued his interest in the diversity of life he observed.
Darwin even found evidence that suggested species once present on earth had vanished.
Researchers today speculate that 99.9% of all species that ever inhabited earth are now extinct.

25. Galapagos Islands
The islands were close together, but had very different climates
Smallest and lowest islands = hot, dry & barren
Hood Island = sparse vegetation
Higher islands had greater rainfall and a different assortment of plants/animals
Isabella Island = rich vegetation
Land Tortoise shell shapes could be used to identify which island it inhabited

26. What observations can YOU make about these species of land tortoise?
Hood Island Tortoise
Pinta Island Tortoise
What predictions can YOU make about the island environment for each tortoise?
What observations can YOU make about these species of land tortoise?
Isabella Island Tortoise

27. Which island would you predict has only low-lying vegetation?
Hood Island Tortoise
Pinta Island Tortoise
Which island would you predict has only low-lying vegetation?
Isabella Island Tortoise

28. Darwin’s Idea
Darwin observed that the plants and animals varied noticeably among the different Galapagos Islands.
However, Darwin wondered if animals living on different islands had once been members of the same species – originating from the same South American ancestor

29. Darwin’s Finches
Darwin observed many different types of “finch” and noticed several different beak shapes.
Why?
He began to notice different shaped beaks were “adaptations” for different food sources

30. Religion’s Role Darwin was a devout Catholic
He knew that his ideas, based on what he observed would provoke the catholic church
He debated over whether or not to publish his results for 25 years.

31. Darwin’s Theory – Descent With Modification
The Origin of Species by Means of Natural Selection – 1858
Every species – living or extinct – descended by reproduction from preexisting species
AND
Species must be able to change over time

32. Sources of Genetic Variation That Lead to Evolution
Sexual Reproduction
Crossing Over
Random Independent Assortment of Chromosomes
Mutations

33. Natural Selection

34. Review What was Lamarck’s hypothesis? What did Darwin believe?
Inheritance of acquired traits
Species changed as environment changed – adaptation and survival of the fittest

35. Standards:
CCSS ELA
I can trace the historical development of the theory of evolution
I can summarize the evidence for the theory of evolution
CCSS ELA
I can critique and evaluate competing evolutionary arguments based on scientific knowledge, empirical evidence and logical arguments regarding relevant factors.

36. Objective (Today I will…)
Explain the idea of “natural selection” and determine “fittest”
Examine how adaptations help animals survive better

37. Darwin’s reasoning for Natural Selection
Overproduction – more offspring are produced than can survive due to competition for resources
Genetic Variation – within a population, individuals have different traits. New traits may appear spontaneously.
Struggle to survive – constant competition may cause some variations/traits to be advantageous
Differential Reproduction – Organisms with the best adaptations will survive and reproduce, thus the advantageous adaptations will become most prevalent in the population.

38. Evolution by Natural Selection
Struggle for existence – each member of a species competes regularly for food, living space and other necessities of life.
main needs: Food, water, living space and ability to reproduce
Who wins?

39. Think – Pair – Share
How can we describe Natural Selection in just 4 words?

40. Survival of the Fittest
How well suited an organism is to it’s environment
Does fittest mean strongest?
Does fittest mean in the best shape?
Fitness – the ability of an individual to survive and reproduce
The result of adaptations

41. What determines fitness?
The Environment!
Anything that helps the organism survive and reproduce better increases an organisms fitness

42. Fitness leads to evolution

43. Change in Allele Frequencies
Natural selection on single-gene traits can lead to a change in allele frequencies and thus to evolution
Example: Red lizards are more visible; black lizards warm faster which allows them to be more active, sooner.

44. Fitness leads to evolution
Peppered Moth evolution
Peppered moth virtual lab

45. Survival of the Fittest
Fittest – the individuals most capable to survive and reproduce for multiple generations
The traits selected as the most useful for survival and reproduction are determined by the organisms environment
Natural Selection accounts for Descent with Modification as species become better adapted to different environments.

46. Birds
Explain to your cat how the environment can determine fitness – use a specific plant or animal as an example.
(Not one Mrs. Stewart gave you)

47. What is a Population?
A group of organisms of the same species, that live in the same area, AND that interbreed

48. Adaptation vs. Acclimatization
Adaptation - Changes in traits in populations over time
Example: White moth population becoming a black moth population after 5 generations.
Acclimatization – individual organism changes physiologically
Example: growing thicker fur in winter

49. Adaptations
Any inherited characteristic that increases an organism’s (and population’s) ability to survive and reproduce
Anatomical or structural characteristics
Porcupine quills - protection
Longer necks in giraffes – find food
Physiological processes
How a plant performs photosynthesis
Instinctual Behaviors
Hunting in packs
Living in burrows

51. Can You… Differentiate between biogenesis and spontaneous generation
Differentiate between Charles Darwin and Jean-Baptiste Lamarck
Explain the idea of “natural selection” and determine “fittest”

52. Mrs. Stewart Honors Biology Central Magnet School
Evidence of Evolution
Mrs. Stewart
Honors Biology
Central Magnet School

53. Standards:
CLE – Explain how genetic variation in a population and changing environmental conditions are associated with adaptation and the emergence of new species.

54. Descent with Modification
Over long periods of time, natural selection produces organisms with different structures, niches or occupy different habitats than their ancestors.
Each living species has descended, with changes, from other species over time.
Result: species today look/act different from their ancestors

55. Common Descent
Look back: Tigers, panthers and cheetahs all share a common ancestor
Look back further: you will find ancestors that these cats share with horses, dogs and bats.
Farther back: common ancestors of mammals, birds, alligators and fishes.
Logic: looking far enough back we should find the common ancestor for all living things

56. Common Descent

57. Evidence of Evolution Homologous & Analogous Structures Fossil Records
Vestigial Structures
Evidence of Evolution
Comparative Embryology
Molecular Biology

58. Evidence of Evolution
Evidence of evolution on your own body

59. Fossil Records Fossils - preserved remains of ancient organisms
Compare fossils from older layers and younger layers and show changes in species over time

60. Fossil Records
Compare fossils found around the world and we can infer when and where different organisms existed.
Fossils also provide evidence about the environment in which the organism existed and for which the organism adapted

61. Transitional Species
Fossil records show species which have features that are intermediate between those of hypothesized ancestors and later descendant species

62. Homologous vs. Analogous Structures
Homologous –structures that share the same basic structure but differ greatly in function
Analogous –structures that vary greatly in structure but share the same function

63. Homologous Body Structures

64. Homologous Body Structures
Similar structures with different functions
Example: The limbs of reptiles, birds and mammals (arms, wings, legs and flippers) vary greatly in function but are all constructed from the same basic bones.

65. Analogous Structures Similar functions but different structures

66. Vestigial Structures
organs/body parts that were once used, but by natural or artificial selection, are no longer necessary

67. Vestigial Organs
Appendix

68. Vestigial Organs
Hip bone in a whale

69. Vestigial Organs
Tailbone in humans

70. Vestigial Organs
Plica Luminaris = Third Eyelid

71. Similarities in Embryology
The early stages, or embryos, of many animals with backbones are very similar.
Does this mean that a human embryo is ever identical to a fish, or a bird embryo? NO
But, many embryos look especially similar during early stages of development.

72. Fish Salamander Tortoise Chicken Pig Man

73. Comparative Embryology
What do these similarities mean?
The same groups of embryonic cells develop in the same order and in similar patterns to produce the tissues and organs of all vertebrates.

74. All animals go through this process
Its at the blastocoel step that we differ
Blastopore could become mouth or anus, etc.

75. The number of amino acids that differ from human hemoglobin
Molecular Biology
Using new technology, we can see how many DNA and RNA sequences organisms share in common
Amino acid sequences used to determine how closely related different species are.
The number of amino acids that differ from human hemoglobin

76. Molecular Biology Amino Acid Similarities
Which two plants are the most closely related according to this chart?

77. Assignment:
Evidence of evolution dry lab activity packet

78. Exit Ticket: Socrative.com
Room Number: Stewart 348
Question: How does the environment determine the “fittest” individual?