Evolution Chapters 21-25

1
Evolution Chapters 21-25
2
Evolution (chapter 22)

• Change over time in the genetic composition of a
  population
• Descent with modification

3
Evolution history
1809 Lamarck publishes his hypothesis of
evolution.
1798 Malthus publishes Essay on the Principle of
Population.
Sketch of a flying frog by Wallace
1812 Cuvier publishes his extensive studies
of vertebrate fossils.
1858 While studying species in the Malay
Archipelago, Wallace (shown above in 1848)
sends Darwin his hypothesis of natural selection.
1795 Hutton proposes his principle of gradualism.
1830 Lyell publishes Principles of Geology.
1790
1870
1809 Charles Darwin is born.
18311836 Darwin travels around the world on HMS
Beagle.
1859 On the Origin of Species is published.
1844 Darwin writes his essay on descent with
modification.
Marine iguana in the Galápagos Islands
4
Evolution History

• Aristotle
• Scala naturae
• Organisms arranged in increasing complexity
• Each form of life was permanent

5
Evolution History

• Linnaeus
• Taxonomy
• Naming classifying organisms
• Binomial system (Genus species)
• Grouping similar species in general categories

6
Evolution history

• Georges Cuvier
• Paleontology
• Study of fossils
• Noted species in some layers of rocks
• Each layer represented catastrophic events

7
Sedimentary rock layers (strata)
Younger stratum with more recent fossils
Older stratum with older fossils
8
(No Transcript)
9
Evolution history

• Hutton
• Change can take place through cumulative effect
• Slow but continuous processes
• Gradualism

10
Evolution history

• Lyell
• Geological processes are happening now
• As they were in the past

11
Evolution history

• Lamacrk
• Two principles
• 1. Use and disuse
• Parts of the body used became stronger
• Those not used deteriorate

12
Lamacrk

• 2. Inheritance of acquired characteristics
• Giraffes stretched necks to reach the leaves
• Pass on the stretched neck

13
(No Transcript)
14
Charles Darwin
15
Darwins voyage
16
Darwins voyage
17
Darwins voyage
18
Darwins voyage
19
Darwins voyage

• Observed adaptations of many species
• Collected fossils
• Resembled animals living in S. America
• Collected different species of birds from
  Galapagos Islands
• Species on the island were similar to the species
  only on SA mainland

20
Finches
21
Darwins voyage

• Conclusion
• Birds adapted to environment to survive
• Adapted to food source that is available

22
Darwin

• Adaptation
• Accumulation of inherited characteristics
• Enhance an organisms ability
• to survive reproduce
• in specific environment
• Result of natural selection

23
Adaptation
24
Adaptation
25
(No Transcript)
26
Fig. 22-12a
(a) A flower mantid in Malaysia
27
Fig. 22-12b
(b) A stick mantid in Africa
28
Wallace

• Developed a theory of natural selection similar
  to Darwins
• Forced Darwin to publish his writings

29
Charles Darwin

• November 24, 1859 Origin of Species
• Focused on diversity of animals
• Origins relationships
• Similarities differences
• Geographic distribution
• Adaptations to surroundings

30
Darwin

• Descent with modification
• through time species accumulate differences
• As a result
• When new species are formed
• Descendent species differ from its ancestor

31
Descent with Modification

• All organisms are related
• Descent from an ancestor that lived awhile ago
• Descendants were in various habitats
• Diverse modifications or adaptations
• Specific ways of life

32
Descent with Modification

• History of life as a tree
• Trunk is the common ancestor
• Branches represent an ancestor of all the lines
  that evolve from that point
• Recent divergence--closely related species
• Many branches dead end
• Many species are extinct

33
Fig. 22-8
Hyracoidea (Hyraxes)
Sirenia (Manatees and relatives)
Moeritherium
Barytherium
Deinotherium
Mammut
Platybelodon
Stegodon
Mammuthus
Elephas maximus (Asia)
Loxodonta africana (Africa)
Loxodonta cyclotis (Africa)
0
104
5.5
34
2
24
Millions of years ago
Years ago
34
Artificial selection

• Modification of crops
• Modification of animals for desired trait
• Domesticated foxes
• Choosing most docile in the offspring
• Mating them
• Over time produced a fox very similar to
  domesticated dogs

35
Variation

• Variation in the population
• Leads to differences in individuals in survival
  reproduction
• Variation among individuals must be genetically
  transmitted

36
Fig. 22-10
37
Natural Selection

• Mechanism for evolution
• Organisms with specific heritable traits
• Produce more offspring with the traits
• Population grows with more offspring with
  advantageous traits

38
Natural selection

• Populations evolve not individuals
• Affects inheritable traits
• Environment greatly influences selection of
  traits
• Trait favorable in one environment
• Detrimental in another
• Change in environment causes change in adaptation

39
Evolution Evidence

• 1. Direct Observations
• 2. Paleontology
• 3. Homology
• Anatomy
• Embryology
• Molecular biology
• 4. Biogeography

40
1. Direct Observations

• Industrial Melanism
• Peppered moth
• Variation of traits
• Increased industrial use caused blackened trees
• Favored darker moth
• 1956 restrictions on pollution
• Favored lighter colored moth

41
Industrial Melanism
42
Bacterial antibiotic resistance
43
1
2,750,000
250,000 base pairs
400
2,500,000
350
Chromosome map of S. aureus clone USA300
500,000
300
250
Key to adaptations
2,250,000
Annual hospital admissions with MRSA (thousands)
200
Methicillin resistance
Ability to colonize hosts
750,000
150
Increased disease severity
100
Increased gene exchange (within species)
and toxin production
2,000,000
50
1,000,000
0
93
94
95
96
97
98
99
00
01
02
03
04
05
Year
1,750,000
1,250,000
1,500,000
44
HIV Drug resistance

• 3TC drug affects HIV reverse transcriptase
• Enzyme makes DNA from RNA genome
• Virus DNA inserted into host DNA
• 3TC Is similar to cytosine
• Resistant HIV carry a different reverse
  transcriptase (enzyme0
• Prevents drug from working

45
2. Fossils

• Show change over time
• Fossils of extinct whales
• Supports idea whales came from a species that was
  a land animal
• Fossil evidence that birds came from dinosaurs

46
Fig. 22-16
(a) Pakicetus (terrestrial)
(b) Rhodocetus (predominantly aquatic)
Pelvis and hind limb
(c) Dorudon (fully aquatic)
Pelvis and hind limb
(d) Balaena (recent whale ancestor)
47
3. Anatomy

• Homologous structures
• Structures with different appearances function
• Derived from a common ancestor
• Forelimbs in humans, cats, whale bats
• Show same arrangement of bones but different uses

48
Homologous structures
49
Fig. 22-17
Humerus
Radius
Ulna
Carpals
Metacarpals
Phalanges
Human
Whale
Cat
Bat
50
Embryology

• Study of early development
• Shows evidence of structures that do not develop
  into adult structures
• Tail
• Gills/ears and throat

51
Fig. 22-18
Pharyngeal pouches
Post-anal tail
Human embryo
Chick embryo (LM)
52
Vestigial organs

• Remnants of organs
• Do not serve any function now
• Resemble structures of their ancestors
• Appendix in humans
• Pelvis/leg bones in snakes

53
Molecular biology

• DNA
• RNA
• Similar in organisms
• Organisms that are very different share a common
  code
• Genes have different functions

54
Molecular biology

• Compare aa sequence for human hemoglobin
• Animals closely related to humans
• Have a higher percent of similar aa than those
  not as closely related
• Rhesus monkey has 95 identical aa
• Frog has 54 identical aa

55
Evolutionary tree

• Diagram that shows evolutionary relationships
• Descent from common ancestor

56
Fig. 22-19
Branch point (common ancestor)
Lungfishes
Amphibians
1
Tetrapods
Mammals
2
Tetrapod limbs
Amniotes
Lizards and snakes
3
Amnion
4
Crocodiles
Homologous characteristic
5
Ostriches
Birds
6
Feathers
Hawks and other birds
57
Convergent evolution

• Independent development of similar structures in
  organisms
• Not directly related
• Found in organisms that live in similar
  environment
• Sugar glider (Australia) (marsupial)
• Flying squirrel (Europe) (placental)

58
Sugar glider
NORTH AMERICA
AUSTRALIA
Flying squirrel
59
Convergent evolution

• Analogous structures
• Evolve independently
• Not common ancestor
• Adapted to similar environments

60
4. Biogeography

• Geographic distribution of species
• Closely related species live in the same
  geographic region
• Distant regions are occupied by very different
  species

61
Biogeography

• Australia
• Home to marsupials
• Embryo develops in a pouch
• Isolated by geography
• Placental mammals
• Embryo develops in uterus