1. Evolution
Diversity of Life

2. Evolution
“Nothing in biology makes sense EXCEPT in the light of evolution.” Theodosius Dobzhansky
Charles Darwin in later years

3. History of Evolutionary Thought

4. Early Ideas On Earth’s Organisms
Aristotle believed species were __________________________arranged by their complexity
Idea lasted 2000 years

5. Early Ideas On Earth’s Organisms
Linnaeus – 1st to group similar organisms and assign them Latin names
Two word name (________________)
Known as __________________________________

6. Lamarck’s Theory of Evolution
Jean-Baptiste Lamarck, 1809
One Of First Scientists To Understand That ____________________
Stated that Changes Are Adaptations To Environment acquired in an organism’s lifetime
Said acquired changes were _______________

7. Lamarck’s Theory of Evolution
Idea called Law of Use and Disuse
If a body part were used, it got __________
If body part NOT used, it _____________

8. Lamarck’s Theory of Evolution
Inheritance of Acquired Characteristics
Proposed That By Selective Use Or Disuse Of Organs, Organisms Acquired Or Lost Certain Traits During Their Lifetime
These _______________________
_____________________________
Over Time This Led To New Species

9. Lamarck’s Theory of Evolution
Use & Disuse - Organisms Could Change The Size Or Shape Of Organs By __________________
___________________
Blacksmiths & Their Sons (muscular arms)
Giraffe’s Necks Longer from stretching)

11. Lamarck’s Theory of Evolution
____________________________
Traits Acquired During Ones Lifetime Would Be Passed To Offspring
Clipped ears of dogs could be passed to offspring!

12. Lamarck’s Theory of Evolution
____________________________
Organisms Are Continually Changing and Acquiring Features That Help Them Live More Successfully In Their Environment
Example: Bird Ancestors Desired To Fly So They Tried Until Wings Developed

13. Lamarck’s Mistakes
Lamarck Did NOT Know how traits were _________ (Traits are passed through _________)
Genes Are NOT Changed By Activities In Life
Change Through Mutation Occurs Before An Organism Is Born

14. Charles Darwin the Naturalist

15. Voyage of the Beagle Charles Darwin Born Feb. 12, 1809
Joined Crew of HMS Beagle, 1831
Naturalist
5 Year Voyage around world
Avid Collector of ____
___________________
Astounded By Variety of Life

16. Darwin’s Voyage of Discovery
A reconstruction of the HMS Beagle sailing off Patagonia.

17. Darwin returned 5 years later in 1836
Darwin Left England in 1831
Darwin returned 5 years later in 1836

18. HMS Beagle’s Voyage

19. The Galapagos Islands Very ____________________
Small Group of Islands 1000 km West of South America
Very ____________________
Animals On Islands Unique
Tortoises
Iguanas
Finches

20. The Galapagos Islands Volcanic islands off the coast of South America
Island species _________ from mainland species & from island-to-island species
Each island had long or short neck tortoises

22. The Galapagos Islands
Finches on the islands resembled a mainland finch
________________of finches appeared on the islands where the available _____________________ (seeds, nuts, berries, insects…)
Finches had different types of beaks adapted to their type of food gathering

24. Darwin’s Observations & Conclusions
The Struggle for Existence

25. Voyage of the Beagle
During His Travels, Darwin Made Numerous Observations And Collected Evidence That Led Him To Propose A Revolutionary Hypothesis About The Way Life Changes Over Time

26. Darwin’s Observations
Patterns of ___________ were shown
Unique _________ in organisms
Species Not Evenly Distributed
Australia, Kangaroos, but No Rabbits
S. America, Llamas

27. Darwin’s Observations
Both Living Organisms & Fossils collected
Fossils included:
Trilobites
Giant Ground Sloth of South America
This species NO longer existed. What had happened to them?

28. Evidence for Evolution – The Fossil Record

29. Definition
__________ is the _____ , _________ _________ in a __________ of organisms over time

30. Darwin’s Observations
Left unchecked, the ___________________of each species will _______ exponentially, generation to generation
In nature, populations tend to remain _______ in size
Environmental resources are ______________

31. Darwin’s Conclusion
Production of more individuals than can be supported by the environment leads to a _________________ among individuals
Only a fraction of offspring survive each generation
_________________

32. Darwin’s Observations
Individuals of a population vary extensively in their characteristics with _____________________________.
Much of this variation between individuals is inheritable.

33. Darwin’s Conclusion
Individuals who inherit characteristics most fit for their environment are likely to leave more offspring than less fit individuals
Called ________________

34. Darwin’s Theory of Evolution
The ________ ability of individuals to ___________________________leads to a gradual change in a population, with favorable characteristics accumulating over generations (natural selection)
New species evolve

35. Ideas That Shaped Darwin’s Thinking
Thomas Malthus

36. Population Growth Thomas Malthus, 1798 Economist
Observed Babies Being Born __________ Than People Were ___________
Population size ___________ by resources such as the Food Supply

37. The Struggle for Existence
Malthus’ Influence:
High Birth Rates & Limited Resources Would Force Life & Death _________
Each Species __________ For:
Food
Living Space
Mates

38. Population Growth
Malthus Reasoned That If The Human Population Continued To Grow Unchecked, Sooner or Later There Would Be __________ Living Space & Food For Everyone
Death Rate Will __________ To Balance Population size & Food Supply

39. Population Growth
Darwin Realized Malthus’s Principles Were Visible In Nature
Plants & Animals Produce Far More __________ Than Can Be Supported
________________
If They Didn’t – Earth Would Be Overrun

40. Darwin’s Theory of Evolution
Organisms ______________________

41. Common Descent with Modification
Darwin proposed that organisms descended from ______________
Idea that organisms change with time, __________ from a common form
Caused evolution of new species

42. Natural Selection Driving force for evolution
During the struggle for resources, _________
___________________
Idea that at least some of the differences between individuals, which impact their survival and fertility, are ________________ .

43. Darwin Presents His Case
Origin of Species
Darwin Presents His Case

44. Publication of “On The Origin of Species”
Upon His Return To England, Darwin Developed His Observations Into The ________________________
But He Did Not Publish For 25 Years –
Why?

45. Publication of “On The Origin of Species”
Darwin Knew That His Theory Would Be Extremely ___________ And Would Be Attacked
His Theory Challenged Established Religious & Scientific Beliefs, Particularly About The Creation Of Man

46. Publication of “On The Origin of Species”
He Refused To Publish Until He Received An Essay From Alfred Wallace
Fellow Naturalist
Independently Developed ___________________
After 25 Years, Someone Else Had Come To The Same Conclusions From Their Observations Of Nature

47. Wallace’s Contribution
Alfred Russel Wallace Independently came to same Conclusion as Darwin that species changed over time because of their _____
____________________
When Darwin read Wallace’s essay, he knew he had to publish his findings

48. Publication of “On The Origin of Species”
Darwin Presented Wallace’s Essay & Some Of His Work At A Scientific Conference of the Linnaean Society in July of 1858
Then He Started On his book “_________________________”
It Took Darwin 18 Months To Complete The Book

49. Natural Variation and Artificial Selection
Abandoned The Idea That Species Were Perfect & Unchanging
Observed Significant Variation in All Species Observed
Observed Farmers Use Variation To Improve Crops & Livestock
Called _______________________

50. Natural Variation and Artificial Selection
_____________ Among Individuals Of A Species
________________________
Selective Breeding To Enhance Desired Traits Among Stock or Crops

51. Natural Variation and Artificial Selection
Key Concept:
In Artificial Selection, Nature Provided The Variation Among Different Organisms, And ____________________Those Variations That They Found ____________

53. Concepts and Controversy
Origin of Species
Concepts and Controversy

54. Evolution By Natural Selection Concepts
The Struggle for Existence (___________ for food, mates, space, water, etc.)
Survival of the Fittest (_________ able to __________ and reproduce)
____________________________(new species arise from common ancestor replacing less fit species)

55. Survival of the Fittest
Fitness
Ability of an Individual To _________________________
Adaptation
_________________________That Increases an Organisms Chance for Survival

56. Survival of the Fittest
Adaptations Can Be:
_________________
Speed, Camouflage, Claws, Quills, etc.
__________________
Solitary, Herds, Packs, Activity, etc.

57. Survival of the Fittest
Fitness Is Central To The Process Of Evolution
Individuals With Low Fitness
___________
Produce __________ Offspring
Survival of the Fittest
AKA Natural Selection

58. Survival of the Fittest
Key Concept
Over Time, Natural Selection Results In Changes In The _______________________Of A Population. These Changes ______________ A Species Fitness In Its Environment

59. Natural Selection Cannot Be Seen Directly
It Can Only Be Observed As Changes In A Population Over Many Successive Generations
Radiation
Fossil Record

60. Descent With Modification
Takes Place Over __________________of Time
Natural Selection Can Be Observed As Changes In
Body Structures
Ecological Niches
Habitats

61. Descent With Modification
Species Today ____________________From Their Ancestors
Each Living Species Has
Descended
With Changes
From Other Species
Over Time

62. Descent With Modification

63. Descent With Modification
Implies
All Living Organisms Are _______
Single Tree of Life
DNA, Body Structures, Energy Sources
_____________________
All Species, Living & Extinct, Were Derived From Common Ancestors

64. Major Problem in Darwin’s Theory
No mechanism to explain natural selection
How could favorable variations be transmitted to later generations?
With the rediscovery of ___________ work in the first half of the 20th century, the missing link in evolutionary theory was found .

65. Opposition to Evolution
The upheaval surrounding evolution began with Darwin’s publication of On the Origin of Species By Means of Natural Selection
The debate continues nearly 150 years later

66. Theory of Evolution Today
Supporting Evidence

67. _____________ Structures

68. Similarities In ______________ Development
Evidence for Evolution - Comparative Embryology
Similarities In ______________
Development

69. Similarities in ______ Sequence

70. Evolution of ________________ in response to selection

71. Evidence for Evolution – Evolution Observed
Evolution of ______________________ in HIV

72. Evidence for Evolution – Evolution Observed
__________________________guppies results in an increase in average size

73. Evolutionary Time Scales
____________: Long time scale events that create and destroy species.

74. Evolutionary Time Scales
___________:
Short time scale events (generation-to-generation) that change the genotypes and phenotypes of populations

75. Evidence of Evolution Key Concept
Darwin Argued That Living Things Have Been Evolving On Earth For Millions of Years. Evidence For This Process Could Be Found In:
The ______________________
The ________________________of Living Species
__________________________of Living Organisms
Similarities In Early Development

76. Fossil Record Earth is __________ of Years Old
Fossils In Different Layers of Rock (sedimentary Rock Strata) Showed Evidence Of Gradual ___________ Over Time

77. Geographic Distribution of Living Species
______________On Different Continents But _______________To Shared Environments

78. Homologous Body Structures
Scientists Noticed Animals With Backbones (Vertebrates) Had Similar Bone Structure
May Differ _______________
Limb Bones Develop In Similar Patterns
Arms, Wings, Legs, Flippers

79. Homologous Body Structures
Structures That Have Different Mature Forms But Develop From The Same Embryonic Tissues
Strong Evidence That All Four-Limbed Animals With Backbones Descended, With Modification, From A Common Ancestor
Help Scientist Group Animals

80. Homologous Body Structures

81. Homologous Body Structures
Not All Serve Important Functions
__________________________
Appendix In Man
Legs On Skinks

82. Similarities In Early Development
______________ Structures Of ______________ Species Show Significant _______________
Embryo – early stages of vertebrate development

83. Human Fetus – 5 weeks

84. Chicken
Turtle
Rat

85. Review

86. Darwin's Theory
Individual Organisms In Nature Differ From One Another. Some Of This Variation Is Inherited
Organisms In Nature Produce _________________________________________________, And Many Of These Offspring Do Not Reproduce

87. Darwin's Theory
Because More Organisms Are Produced Than Can Survive, Members Of Each Species Must ______________________________________________________
Because Each Organism Is Unique, Each Has Different Advantages & Disadvantages In The Struggle For Existence

88. Darwin's Theory
Individuals ___________________To Their Environment ________________ & Reproduce Successfully – Passing Their Traits To Their Offspring.
Species Change Over Time. Over Long Periods, Natural Selection Causes Changes That May Eventually Lead To New Species

89. Darwin's Theory
Species Alive Today Have ______________________________________________________From Species That Lived In The Past
All Organisms On Earth Are United Into A Single Tree Of Life By Common Descent