Evolution: Evidence
1. Tenets of Evolution
a. Species change overtime
b. Modern species descended from ancient species
2. Fossils
a. Evidence of life
b. Remains of organisms
c. Traces of organisms
d. 1/10 of 1% organisms become fossiles
3. What They Tell Us
a. Appearance
b. When it lived
c. Where it lived
d. How it changed
e. Dates of sediments
4. What is Needed to Make a Fossil
a. Protection from scavengers
i. Cover by sediment
ii. Cover by amber
iii. Cover by tar
b. Protection from weathering
5. Methods: Petrification
a. Original material replaced by rock
6. Permineralization:
a. Minerals fill air spaces
i. SiO2, CaO2, Fe
b. Original material remains
c. Preserves hard structures
7. Replacement:
a. Water dissolves material
b. Minerals replace material
i. 1 molecule at a time
ii. SO3, PO3
c. Preserves hard and soft tissue
8. Methods: Carbonization
a. Sediment exposed to heat and pressure
b. Carbon replaces organic compounds
c. Preserves soft tissue
9. Methods: Molds and Casts
a. Organism buried
b. Sediment hardens
c. Water seeps in, material decays
d. Sediment fills mold to make cast
e. Preserves outer structure
10. Trace Fossils
a. Footprints, trails, burrows, nests
b. Approximate
i. Size
ii. Weight
iii. Locomotion
iv. Behavior
11. Original Remains
a. Amber: traps small plants and animals
b. Freezing: mammoths in Siberia
c. Mummification: tissue dries before decay
12. Index Fossils
a. Characterize a region/time
b. Exist for limited time
c. Abundant
d. Distinctive appearance
e. Wide distribution
13. Dating: Sedimentary
a. Newest material on top
b. Position gives relative age
14. Dating: Radioisotpes
a. Give actual date of material
b. Complements sedimentary dating
15. Fossil Record
a. Date fossils
b. Arrange chronologically
c. Look for similarities and differences
16. Equus Record
a. Eohippus (60mya): 4 toes
b. Mesohippus (50 mya): 3 toes, 1 main, 2 side
c. Merychippus (7 mya): 1 main toe, 2 vestigial
d. Equus (10,000 yr): 1 toe
17. Whale Record
a. Pakicetus: 50 mya
i. Lived in marsh land
b. Ambulocetus: 47 mya
i. Shallow water, still had legs
c. Kuthchicetus: 46mya
i. Legs modified with web feet
18. Whale Record
a. Rodhocetus: 45mya
i. Tail modified for water
ii. Paddle with back legs
b. Dorudon: 40 mya
i. Tail flattened horizontally
ii. Front and back legs modified to flipper
iii. Pelvis lost
19. Modern Whale
a. Front legs flippers
b. Back legs vestigial
c. Pelvis lost
d. Vertebral column modified
e. Tail horizontal
20. Evolution of Complexity
a. Prokaryote bacteria: 325 bya
b. Simple eukaryotes: 2 bya
c. Multicelled eukaryotes: 1.2 bya
d. Cambrian explosion: 600 mya
e. Modern organisms most complex
21. Hominid Evolution
a. Ardipithecus ramidus: 4.5 mya
b. Australopithecus anamensis: 4.1 mya
c. Australopithecus afarensis: 3.6 mya
22. Hominid: A. afarensis
a. 3.6 mya
b. Earliest bones with distinctly human characteristics
c. 1.5 m
d. Braincase: 450 cm3
e. Bipedal
f. Plant eater
23. Hominid: A. africanus
a. 2.2 mya
b. Taller and heavier bone structure
c. Braincase 600 cm3
24. Hominid: Homo habilus
a. “Handy Man”
b. 2 mya
c. Braincase: 800 cm3
d. Made/used simple tools
e. Well developed speech area
f. Meat eater
25. Hominid: H. erectus
a. “Upright Man”
b. 1.6 mya
c. 1.7 m
d. Braincase 1,250 cm3
26. Hominid: H. erectus
a. Heavy skull and bone structure
b. Skull shows evidence of speech
c. Well made tools
d. Cooking fires
e. Evidence of culture/burials
27. Hominid: H. sapeins neanderthallus
a. “Wise Man” from Neanderthal Ge
b. 130, 000 years ago
c. 1.6 m
d. Braincase 1,450 cm3
e. Heavy skull/bones
28. Hominid: H. sapiens neanderthallus
a. Complex tools
b. Built shelter
c. Made clothing
d. Well developed culture and rituals
29. H. sapiens floresiensis
a. 95,000 to13,000 years ago
b. 1 meter tall
c. Braincase: 450 cm3
d. Human like teeth, narrow nose, shape of braincase
e. Resembles H. erectus more than H. sapiens
30. H. sapeins floresiensis
a. Brain reconstruction resembles H. Sapiens
b. Advanced tools, similar to H. sapiens
c. Group hunting
d. Fire and cooking
31. Hominid: H. sapiens sapiens
a. “Wise Man”
b. 35,000 years ago
c. 1.8 m
d. Braincase 1400 cm3
e. Lighter bone and skull structure
f. Well designed and constructed tools
g. Sophisticated culture and art
32. Modern Evidence
33. Common Ancestry: Honeycreepers
a. 23 species of Hawaiian bird
b. Common skeleton/muscles
c. Different bills for food source
d. Similarity of DNA indicates recent divergence
34. Common Ancestry: Galapagos Finches
a. 11 species of finch
b. Common skeleton/muscle structure
c. Similar DNA
d. Bills vary by food source
35. Homologous Structures: Priniciple of Connections
a. Similar anatomy but different function
b. May be
i. Modified
ii. Reduced
iii. Enlarged
iv. Eliminated
c. May not be transposed
36. Homologous Structures: Composition
a. Structure derives from same part of embryo
b. Structures made of same material
c. Similarity indicates potential common ancestor
37. Vestigial Organs
a. Structure with no useful function
i. Tailbone
ii. Appendix
b. Homologous to useful structure in other organisms
c. Indicate potential replationshp
38. Biochemical
a. Same amino acids
b. Same genetic code
c. Cytochrome C for aerobic respiration
d. Similar blood proteins
39. Biochemical
a. Shared master control and homeotic genes
b. Similar gene sequences and proteins
i. Variations in amino acid sequence indicate degree of relationship
ii. Variations indicate when line divided
40. Embryology
a. Early stages nearly identical
b. Follows same pattern of development
c. Show genetic similarities
41. Theories of Evolution
42. Erasmus Darwin
a. God is first cause only
b. Life adapted to Earth’s change
c. Aquired characterisitics passed on
43. Lamarck
a. Similar species had common ancestor
b. Simple evolves to complex
c. Acquired traits
i. Result of behavior or environment
ii. Passes on to offspring
iii. Discredited
d. First clear statement of tenets of evolution
44. Darwin: Background
a. Son of wealthy physician
b. Studying at Cambridge for clergy
c. Early interest in natural history/beetles led to invitation to sail on Beagle
45. Darwin: Guidance
a. Lyell
i. Ancient Earth
ii. Uniformitarianism
iii. Species created to fill niche
iv. Competition for resources determines survival
46. Darwin: Guidance
a. Malthus
i. Potential for growth limited by resources
ii. Mechanism must exist to control
iii. Best adapted organisms survive
47. Darwin: The Beagle
a. 5 years to South American and South Pacific
b. Ship mission: mapping
c. Darwin spent most time ashore
i. Observing
ii. Collecting
iii. Mapping geology
iv. Searched for evidence to support Lyell
48. Darwin: Analysis
a. Studied collections for 15 years
b. Added work with barnacles
c. Developed theory of evolution
d. Developed natural selection as mechanism
e. Did not publish, feared rejection and ridicule
49. Wallace
a. Self educated son of poor merchant
b. Traveled to South America and Malay Archipelago
c. Collected and studied plants and animals
d. Worked independently of Darwin
e. Developed theory of evolution and natural selection
f. Asked Darwin to review his work
50. Darwin: “Origin of the Species”
a. Published in response to Wallace
b. Descent with modification
i. New forms descend from older forms
ii. Random variation gives rise to similar forms
51. Darwin: “Origin of the Species”
a. Modification by Natural Selection
i. Random variation affects survivability
ii. Variations better matched with environment passed on
iii. Genetic makeup of population gradually changes
52. Natural Selection
a. Inactive process
(1) Organism does not choose traits
(2) Traits develop randomly
(3) Fitness determines what is passed on
b. Inability to adapt to environment produces extinction
53. Essential Components
a. Pattern exists
i. DNA
ii. Behavior
iii. Body structure
b. Pattern can be copied reliably
c. Variation occurs in copying
i. Errors
ii. Recombination
54. Essential Components (cont.)
a. Populations with variations compete
b. Environment favors one variation (natural selection)
c. More successful variations are passed to offspring
55. Catalysts to Evolution
a. Speciation
i. Resists breeding with parent population
ii. Prevents dilution of adaptation
b. Sexual Reproduction
c. Splitting Population
d. Empty Niches
e. Climate Fluctuations
56. Patterns: Coevolution
a. Change in unrelated species in close contact
b. Predator/prey
c. Parasites/hosts
d. Pollinators:
i. Develop tongue/head to fit plant
ii. Plants develop colors/shapes/odor to attract pollinators
57. Patterns: Convergent Evolution
a. Unrelated organisms develop similar structure/phenotype
b. Adapt to same environment/function
58. Divergent Evolution
a. Species in isolated environment
b. Develop differing phenotypes in response to environment
c. Adaptive Radiation: many new species from one