Evolution Chapter 13

1
EvolutionChapter 13

• A change over time

2

• 100(the making of a theory)
• 98(darwin in the galapagos)
• http//video.nationalgeographic.com/video/oceans-n
  arrated-by-sylvia-earle/oceans-galapagos?sourcere
  latedvideo
• ?? If time
• http//www.hulu.com/watch/403434detailsexpand

3
The Theory of Evolution

• Evolution literally means to change over time.
• A theory is a well supported, testable
  explanation that observes observations from the
  natural world

4
Questions that evolution attempts to answer.

• How do species adapt to changes in the
  environment?
• How do new species develop?

5
Charles Darwin

• 1809-1882
• Studied to be a doctor and a minister
• 1831 sailed around the world as a naturalist on
  the HMS Beagle

6
HMS Beagle
7
Darwins Voyage
8
Galapagos Islands
9
Galapagos Islands
10
(No Transcript)
11
(No Transcript)
12
15-2 Darwins Influences
13
James Hutton

• Geologist
• Proposed that the earth was millions of years old
  based on geologic evidence

14
Sir Charles Lyell

• Geologist
• Proposed that geologic changes occur slowly over
  long periods of time.
• Darwin read his book, Principles of Geology, on
  the Beagle

15
Jean Baptiste Lamarck

• French Naturalist
• Published his ideas on evolution in 1809 in
  Philosophie zoologique

16
Lamarcks Hypothesis

• Organisms Strive for Perfection all
  individuals are trying to better themselves

17
Lamarcks Hypothesis

• Use and Disuse
• If an individual uses a trait it will be more
  useful
• If an individual does not use a trait it will
  decrease in usefulness

18
Lamarcks Hypothesis

• Inheritance of Acquired characteristics

19
Analyzing Lamarcks Hypothesis

• There is no evidence to suggest that plants and
  animals are trying to improve themselves

20
Analyzing Lamarcks Hypothesis

• Use and disuse do not change all characteristics
• Stretching will not make you taller
• Reading will not make your eyesight better

21
Analyzing Lamarcks Hypothesis

• Acquired characteristics are not inherited
• A mouse that loses its tail will still produce
  offspring with tails

22
Erasmus Darwin

• Charles Darwins Grandfather
• Physician and Scientist
• 'All vegetables and animals now living were
  originally derived from the smallest microscopic
  ones.'

23
Thomas Malthus

• Economist
• Human Population would be limited
• Starvation
• War (Competition)
• Disease

24
15-3 Darwin Presents His Case
25
Alfred Wallace

• Developed his own theory of Natural Selection
• Contacted Darwin
• This caused Darwin to finally publish his theory
  with Wallace

26
On Origins of Species

• After publishing with Wallace, Darwin submitted
  all of his ideas in a book titled On Origin of
  Species, By Means of Natural Selection in 1858

27
Artificial Selection

• Darwin was influenced to believe change was
  possible because of the humans selecting for
  traits in plants and animals.

28
(No Transcript)
29
Darwins Theory

• Evolution Change is driven by natural selection

30
Summary of Darwins Theory

• Major components of natural selection
• Variation
• Competition for Resources
• Survival (camo)
• Fitness (resistance to pesticide)

31
Variation

• There are differences within a population
• Mutation and Sexual Reproduction

32
Competition for resources

• Not all offspring will survive
• Starvation
• Overcrowding
• Predation

33
Fitness

• Some of the variants will have an advantage over
  the others, they will survive and produce more
  offspring

34
Reproduction and Inheritance

• These advantages will be passed on to the next
  generations

35
Descent with Modification

• Species alive today are descended with
  modification from ancestral species

36
Tree of Life Video 101(the human family tree)

• All species are connected on a single tree of life

37
Modern Theory

• Mendels discoveries in genetics explained a
  great deal in evolution

38
Evidence for Evolution

• Fossil Record
• Anatomy
• Development
• Molecular Evidence

39
Fossil Record

• Since most of the ancestor species are extinct,
  fossils are the only evidence that can be
  examined.
• Intermediate missing link fossils are very
  informative

40
Archaeopterix

• A fossil of a bird like creature
• Has feathers, teeth and claws in its wings

41
Whale Ancestors

• 53(whale evoulution)
• http//www.youtube.com/watch?vlx079oEgKKs

42
Anatomy

• Structures similarities in body structure
  indicates organisms are related

43
Homologous Structures
Structures that have common function and design
(ancestry)

44
(No Transcript)
45
Vestigial Organs

• Structures that have reduced size and or function
• Video 54(vestigial struc), 99(Proof of evol)
• http//www.youtube.com/watch?vpbc7ee9u1JE

46
(No Transcript)
47
(No Transcript)
48
(No Transcript)
49
(No Transcript)
50
Developmental Evidence

• Similarities in embryonic development are
  interpreted to mean closer relationships.

51
Developmental Evidence

• Similarities in embryonic development are
  interpreted to mean closer relationships.

52
Molecular Evidence

• Organisms are considered to be more closely
  related if
• DNA sequences in genes are more similar
• Amino acid sequences in proteins is more similar

53
Molecular Evidence

• Organisms are considered to be more closely
  related if
• DNA sequences in genes are more similar
• Amino acid sequences in proteins is more similar

54
Strengths of Darwins Theory

• Many discoveries in Physics, Geology and Biology
  have supported and expanded Darwins ideas

55
Strengths of Darwins Theory

• Many discoveries in Physics, Geology and Biology
  have supported and expanded Darwins ideas

56
Weaknesses of Darwins Theory

• Researchers still debate how new species arise
  and how they become extinct.
• The origin of life is still very uncertain

57
Evolution of Populations

• Chapter 14

58
Video 95(are athletes really getting faster)

• https//www.youtube.com/watch?v8COaMKbNrX0

59
Genes and Variation

• Variation differences between individuals of a
  species
• Produced by two processes
• Mutation random changes in DNA
• Sexual Reproduction- combining genes from two
  gametes

60
Single Gene Traits

• Several traits are controlled by a single gene
  and are either dominant or recessive.

61
Polygenic Traits

• Poly-genic means many genes
• Most traits are controlled by several genes and
  can show up in many different forms.

62
Normal Curve

• Most individuals are intermediate, extremes are
  less common

63
Microevolution

• Micro small
• Microevolution is change within a species
• Gene Pool all of the genes in a population
• Allele Frequency how many times a certain
  allele shows up in the population

64
Microevolution

• Any change in Allele frequency in a population is
  considered microevolution

65
English Peppered Moth

• The English Peppered Moth
• The moth was usually white with dark spots
• During the Industrial Revolution (1850s) soot
  covered many of the white barked trees
• More and more dark colored moths appeared at the
  same time
• Kettlewells experiments suggested this was due
  to natural selection

66
English Peppered Moth

• The English Peppered Moth
• The moth was usually white with dark spots
• During the Industrial Revolution (1850s) soot
  covered many of the white barked trees
• More and more dark colored moths appeared at the
  same time
• Kettlewells experiments suggested this was due
  to natural selection

67
(No Transcript)
68
Microevolution in Humans

• Sickle Cell Anemia is a recessive (hh) disease
  found mainly in Africa
• A carrier (Hh) for the disease has resistance to
  malaria

69
Delta 32 Mutation

• Delta 32 mutation occurs in 10-15 of whites of
  European descent
• This mutation gave resistance to the plague
• Most of the people without this allele died of
  the plague causing the allele frequency to rise
• The mutation also gives resistance to HIV
  infection

70
(No Transcript)
71
(No Transcript)
72
(No Transcript)
73
(No Transcript)
74
(No Transcript)
75
(No Transcript)
76
Selection

• Selection can be one of 3 forms
• Directional
• Stabilizing
• Disruptive

77
(No Transcript)
78
Stabilizing Selection

• Both Extremes are selected against
• The population is stabilized

79
Directional Selection

• One of the extremes is selected against, the
  population shifts away

80
Disruptive Selection

• The most common variation is selected against
  spitting the species two groups

81
Genetic Drift

• In small population individuals may pass on more
  genes by chance. This is called genetic drift.
• Large populations are not affected by genetic
  drift

82
Genetic Drift
Population 18 9 Heads 9 Tails
83
(No Transcript)
84
Population 18 6 Heads 12 Tails
85
Can a species stop evolving?

• Hardy Weinberg equilibruim
• in order for evolution of a species not to occur
  
• (all allele frequencies stay the same)
• 5 evolutionary forces must not act

86
Hardy-Weinberg Equilibrium

• Populations do not evolve if there is
• Random Mating
• no movement into or out of the population
• no genetic drift, large population
• no natural selection
• no mutation

87
Evolution will NOT occur in a population if 
1.    mutation is not occurring
2.   natural selection is not occurring
3.   the population is infinitely large (no genetic drift)
4.   all mating is totally random
5.   there is no migration in or out of the population
88
16-3 The Process of Speciation

• Speciation the production of a new species
• Species a group of individuals that reproduce
  in nature and produce fertile offspring
• Isolation the factor that prevents the new
  species from reproducing with the ancestral
  species

89
Behavioral Isolation

• Mating songs or rituals are different, so the two
  species dont interbreed.
• Greater prairie chicken vs Lesser prairie chi

90
Behavioral Isolation

• Groups are not attracted to each other for
  mating..beefalo (fertile)

91
Geographic Isolation

• Groups are physically separated and no longer
  interbreedantelope squirals

92
Temporal Isolation

• Groups reproduce at different times of day or year

93
Mechanical Isolation

• Structural differences prevent mating between
  individuals of different groups

94
Ecological Isolation

• Groups are adapted to different habitats, hybrids
  arent adapted well to either

95
Reproductive Failure

• Mating between groups fail to produce fertile
  offspringliger, mules

96
Hybrids

• http//en.wikipedia.org/wiki/Tigon

97
Speciation Continued

• Once populations are isolated, different
  pressures select different traits
• When the populations will no longer interbreed,
  new species have been formed

98
Natural Selection - 2 forms

• Ecological Selection better suited to survive
  in the environment
• Sexual Selection
• Males compete for access to females
• Females select males with good gene markers

99

• Sexual selection see video 55(why sexy is sexy)
• Video 102(weird things your body does)

100
Sexual Dimorphism

• Dimorphism di-morph-ism
• Two forms
• Males are usually larger
• Males would have ornaments (antlers, manes,
  colors)

101
(No Transcript)
102
Patterns of Evolution
103
Macro Evolution

• Macro Large
• Idea that species can split to form new species
• All life forms are related through a common
  ancestor

104
Divergent Evolution

• Similar species develop different adaptations to
  different environments

105
Convergent Evolution

• Two species develop similar adaptations to the
  same environment.

106
Coevolution

• Two or more species adapting to each
  other..garter snake and newt

107

• In each of these populations, the snakes exhibit
  resistance to the toxin and successfully prey
  upon the newts. Successful predation of the
  rough-skinned newt by the common garter snake is
  made possible by the ability of individuals in a
  common garter snake population to gauge whether
  the newt's level of toxin is too high to feed on. 

108

• T. sirtalis assays toxin levels of the
  rough-skinned newt and decides whether or not the
  levels are manageable by partially swallowing the
  newt, and either swallowing or releasing the
  newt. 9Toxin-resistant garter snakes are the
  only known animals today that can eat a
  rough-skinned newt and survive.

109
Rate of Evolution Slow and Steady or in Spurts?

• Gradualism the idea that small changes build up
  slowly over time to produce large changes.
• Expectations many intermediate missing link
  fossils

110
(No Transcript)
111
Punctuated Equilibrium

• The idea that populations go through periods of
  stability followed by short periods of rapid
  change.
• Expectations fewer intermediate fossils

112
(No Transcript)
113
Endosymbiont Theory

• Endo inside
• Symbiont symbiotic mutualistic relationship

114
Endosymbiont Theory

• This theory suggests that mitochondria and
  chloroplasts were once independent living
  organisms
• These organisms were eaten by larger cells, but
  remained alive

115
Endosymbiont Theory

• Evidence for endosymbiosis
• Each mitochondrian has its own circular
  chromosome of DNA
• Very similar to a bacteria
• Reproduce on its own
• Ribosomes are very similar to bacterial ribosomes