Evolution for AP College Biology

2. In questions of science, the authority
of a thousand is not worth the sound
reasoning of a single individual.
- Galileo Galilei (1564-1642)

6. FACT Individuals within populations
vary.
FACT Some of the variation among
individuals is passed on to
offspring.
FACT Populations produce more
offspring than can survive.
FACT Survival and reproduction are not
random.
INFERENCE Natural selection
causes evolution.

8. Evolution of Jelly bellicus
0
1
2
3
4
5
6
7
8
breakfast lunch dinner
numberofsurvivors
green
green spots
orange
yellow spots
red
red spots
dk brown spots
tan spots

9. Evolution of Jelly bellicus
0
2
4
6
8
10
12
breakfast lunch dinner
numberofsurvivors
green
green spots
orange
yellow spots
red
red spots
dk brown spots
tan spots

10. Evolution of Jelly bellicus population shift
0
2
4
6
8
10
12
14
beginning after 1st meal after 2nd meal after 3rd meal
numberinpopulation
green
green spots
orange
yellow spots
red
red spots
dk brown spots
tan spots

12. “It is not the strongest of the
species that survive, but those
most responsive to change.”
- Charles Darwin

15. Figure 22.9
Brussels
sprouts
Kale
Selection
for leaves
Selection for
axillary (side)
buds
Selection for
apical (tip) bud
Cabbage
Broccoli
KohlrabiWild mustard
Selection
for stems
Selection
for flowers
and stems

17. What conditions are necessary
for natural selection?
• Is it necessary for the population to
change over time?
• Can it work if there is no variation in the
population?
• Can it work if variation is not heritable?
• Is a reproductive advantage of some
phenotype necessary?

18. What conditions are necessary
for natural selection?
• Change over time
• Variation
• Heritability
• Reproductive advantage

19. Three-spined Stickleback Fish
Lake experiment

31. Same species or different species?
https://learn.genetics.utah.edu/content/evolution/species

33. What is a species?
• Species = a group of potentially interbreeding
organisms.

35. What is a species?
• Species = a group of potentially interbreeding
organisms that produce fertile offspring.

37. What is a species?
• Species = a group of potentially interbreeding
organisms that produce fertile offspring,
regularly in nature.

43. https://www.hhmi.org/biointeractive/sorting-finch-species

44. So what is a species?
Learn.genetics what is a species?

47. So what is a species?
• Depends on who is deciding and for what
purposes.
• Different strengths & weaknesses of each
species concept:
- Biological - Genetic
- Morphological - Fossil
- Ecological - Biochemical (bacteria)
- Phylogenetic

48. How could new species arise?
Learn.genetics reproductive barriers

50. Prezygotic barriers
Habitat
Isolation
Temporal
Isolation
Behavioral
Isolation
Mechanical
Isolation
Gametic
Isolation
Individuals
of
different
species
MATING
ATTEMPT
FERTILIZATION
(a) (c) (e) (f)
(b)
(g)
(d)

51. Reduced Hybrid
Viability
Reduced Hybrid
Fertility
Hybrid
Breakdown
FERTILIZATION
VIABLE,
FERTILE
OFFSPRING
Postzygotic barriers
(k)
(h) (i)
(j)
(l)

52. What causes evolution?

53. How do we define evolution?
• Change in allele frequency of a
population’s gene pool,
• leading to change in organisms over time.
• Measure allele frequencies
How do we measure evolution?

55. Hardy-Weinberg Equilibrium
• p = % of dominant alleles in a population
• q = % of recessive alleles in a population
• % of homozygous dominant individuals =
• % of homozygous recessive individuals =
• % of heterozygous individuals =
• p + q = 1
• p2 + 2pq + q2 = 1

56. Hardy-Weinberg Equilibrium
• Out of 1000 stoneflies collected, 160 are
apterous (no wings), a Mendelian recessive
trait.
• What are the percentages of homozygous
dominant stoneflies and heterozygous
stoneflies in the population?
• What percentage of each genotype will exist
in the next generation?
• Allele frequencies never change!

57. Conditions necessary for
Hardy-Weinberg Equilibrium
• No mutations
• No migration in or out of population
• No advantage of any phenotype over others
• Random mating
• Large population size

58. Forces that cause evolution
• Natural selection
• Non-random mating
• Mutation
• Gene flow
• Genetic drift

59. Population Genetics Lab
• Question: How do selective pressure,
heterozygote advantage, and population size
affect allele frequencies and evolution?
• Hypotheses:
 selective pressure against an allele’s phenotype
will _______ the allele’s frequency.
 Heterozygote advantage will ________ the
frequency of a dominant allele.
 Allele frequencies will fluctuate more in ______
size populations.

60. Population Genetics Lab
• Methods
1.Begin each simulation by holding 1 dime
(representing a dominant allele) and 1 penny
(representing a recessive allele) in opposite
hands.
2.Each person selects a “mate” randomly in a
“hermaphroditic” population like slugs. Each
person holds a penny in one hand and a
dime in the other hand.

63. Population Genetics Lab Methods
3. Person 1 selects a partner’s hidden coin,
then person 2 selects a hidden coin.
4. The offspring is considered person 1’s
offspring and the genotype is determined by
what coins were selected.
5. Repeat the process for person 2’s offspring.
6. Record the genotpyes.
7. Exchange coins, if needed, from the class
gene pool.

64. Population Genetics Lab Methods
8. Record class data for numbers of
 homo. dom., heterozygous, homo. recessive
 frequencies of dominant & recessive alleles
9. Repeat for a total of 5 generations.
10.Repeat all steps for Case 2, 3, & 4
For Case 2 – selection:
• Homozygous recessive offspring die and
another mating must occur.

65. Population Genetics Lab Methods
For Case 3 – heterozygote advantage:
• Homozygous recessive offspring die and
• Homozygous dominant offspring must toss a
coin to see if the offspring lives or not. Head
it lives, tails it dies and must choose again.
For Case 4 – genetic drift:
• Class divides into 3 small groups,
reproductively isolated from each other.

66. What causes evolution?

75. Forces that cause evolution
• Natural selection
• Mutation
• Gene flow
• Genetic drift
• Non-random mating

77. • Phylogeny = study of evolutionary
relationships among organisms.
• Systematics = evolutionary classification
= classification based on phylogeny
• Cladogram = phylogenetic tree = a
branching diagram representing
phylogeny of a group

79. Which is more correct?

80. or this?
Tree diagrams learn.genetics

82. Hypothetical genealogy
of local population of
plants

83. How genealogy of sexual population is
included in a phylogenetic tree

84. Tree diagram is meant to represent an
actual history of evolutionary lineages that
have branched over time

85. Four trees, all depict
same evolutionary history

86. Some important terms used
to describe phylogenetic trees
Learn.genetics tree diagrams

87. How to read a tree
in terms of
evolutionary
relationships

88. Three trees, all depict the same
evolutionary history

89. A clade includes
all and only the
descendants of a
paticular ancestor

90. How trees
show
evolutionary
history

91. Ancestral
group
sister taxa
sister taxa
sister taxa
Basal taxon
Rooted

92. Monophyletic or Paraphyletic

93. Monophyletic or Paraphyletic

94. Monophyletic or Paraphyletic

95. Monophyletic or Paraphyletic

96. Constructing phylogenetic trees

97. trait
wings cerci gills epiproct drumming
species 1 long wings stubs present single yes
species 2 long wings long absent single no
species 3 short wings stubs absent forked yes
ancestral
condition
long wings long present single no

99. DNA base site
1 2 3 4
species 1 C T A T
species 2 C T T C
species 3 A G A C
ancestral state A G T T

100. Learn.genetics interactive phylogenetic tree

111. Advantages of scientific names
over common names
• Panthera tigris
• Panthera onca
• Panthera leo
• Elephas maximus
• Loxodonta africanus
• Capnia utahensis
• Isoperla mormona
• Pediculus humanus capitis

112. Advantages of scientific names
over common names
• Pteronarcys californica
• Pteronarcella badia
• Capnia coloradensis
• Isoperla coloradensis
• Capnia gracilaria

113. Panthera tigris
Panthera onca
Panthera leo
Felis sylvestris
Felis concolor
Lynx rufus
Canis lupus
Canis familiaris
Elephas maximus
Loxodonta africanus
Python regius
Apis melifera

114. Panthera tigris
Panthera onca
Panthera leo
Felis sylvestris
Felis concolor
Lynx rufus
Canis lupus
Canis familiaris
Elephas maximus
Loxodonta africanus
Python regius
Apis melifera

115. Panthera tigris
Panthera onca
Panthera leo
Felis sylvestris Felidae
Felis concolor
Lynx rufus
Canis lupus
Canis familiaris
Elephas maximus
Loxodonta africanus
Python regius
Apis melifera

116. Panthera tigris
Panthera onca
Panthera leo
Felis sylvestris Felidae
Felis concolor
Lynx rufus
Canis lupus
Canis familiaris Canidae
Elephas maximus
Loxodonta africanus
Python regius
Apis melifera

117. Panthera tigris
Panthera onca
Panthera leo
Felis sylvestris Felidae
Felis concolor
Lynx rufus
Canis lupus
Canis familiaris Canidae
Elephas maximus Elephidae
Loxodonta africanus
Python regius Pythonidae
Apis melifera Apidae

118. Panthera tigris
Panthera onca
Panthera leo
Felis sylvestris Felidae
Felis concolor
Lynx rufus
Canis lupus
Canis familiaris Canidae
Elephas maximus Elephidae
Loxodonta africanus
Python regius Pythonidae
Apis melifera Apidae

119. Panthera tigris
Panthera onca
Panthera leo
Felis sylvestris Felidae
Felis concolor
Lynx rufus Carnivora
Canis lupus
Canis familiaris Canidae
Elephas maximus Elephidae
Loxodonta africanus
Python regius Pythonidae
Apis melifera Apidae

120. Panthera tigris
Panthera onca
Panthera leo
Felis sylvestris Felidae
Felis concolor
Lynx rufus Carnivora
Canis lupus
Canis familiaris Canidae
Elephas maximus Elephidae
Loxodonta africanus
Python regius Pythonidae
Apis melifera Apidae

121. Panthera tigris
Panthera onca
Panthera leo
Felis sylvestris Felidae
Felis concolor
Lynx rufus Carnivora
Canis lupus
Canis familiaris Canidae
Elephas maximus Elephidae
Loxodonta africanus
Python regius Pythonidae
Apis melifera Apidae

122. What tools do biologists use to
identify organisms?
• Dichotomous keys
– Series of choices ending in a final result
– Each step has 2 and only 2 choices
– Like choose your own adventure book
• Collections
– used to verify identifications
– used to compare specimens across time and
distance

124. Propose hypotheses for how life
on Earth came to be the way it
is now

129. Evaluating the Evidence for
Evolution (by common descent)
• Direct observations
– Antibiotic resistant bacteria
– Drug resistant germs
– Insecticide resistant insects
– Herbicide resistant weeds
– Galapagos finch beaks
– Cichlid fish in Lake Victoria
– Many, many other examples

130. Evaluating the Evidence for
Evolution (by common descent)
• Direct observations
• Biological classification
– What explains why different organisms or
species share the same traits?
– Taxonomic groups are determined by shared
similar characteristics.

131. Evaluating the Evidence for
Evolution (by common descent)
• Direct observations
• Biological classification
• Homology in comparative anatomy

133. Convergent Evolution
Penguin
Dolphin

134. Flying squirrel Flying phalanger

135. Groundhog Wombat

136. Badger Tasmanian devil

137. Coyote Tasmanian tiger

138. American Cactus African Euphorbia

139. Coevolution

140. Evaluating the Evidence for
Evolution (by common descent)
• Direct observations
• Biological classification
• Homology in comparative anatomy
– Homologous structures
• Vertebrate limbs, vertebrae, skulls, exoskeletons
– Vestigial traits

141. Evaluating the Evidence for
Evolution (by common descent)
• Direct observations
• Biological classification
• Homology in comparative anatomy
– Homologous structures
– Vestigial structures
• Appendix, wisdom teeth, human body hair, snake
“claws”, whale leg bones, micropterous insects,
flightless birds and insects

143. Evaluating the Evidence for
Evolution (by common descent)
• Direct observations
• Biological classification
• Homology in comparative anatomy
• Homology in development

147. Evaluating the Evidence for
Evolution (by common descent)
• Direct observations
• Biological classification
• Homology in comparative anatomy
• Homology in development
• Homology in biochemistry
– The more similar DNA, proteins, and other
biochemistry is, the more closely related
organisms are.

149. Evaluating the Evidence for
Evolution (by common descent)
• Direct observations
• Biological classification
• Homology in comparative anatomy
• Homology in development
• Homology in biochemistry
• Transition fossils

157. Evaluating the Evidence for
Evolution (by common descent)
• Direct observations
• Biological classification
• Homology in comparative anatomy
• Homology in development
• Homology in biochemistry
• Transition fossils
• Biogeography

158. Hypotheses to account for
distribution of organisms
• Separate origins
– penguins & auks, gazelle & deer
• Migration
– weeds, starlings, rabbits in Australia
• Vicariance
– Lednia stoneflies, meadowlarks
• Continental drift
– Cichlid fish in Africa & S. America
– Drumming stoneflies in N. hemisphere

160. Avoid these misconceptions
• Individuals evolve.
• Changes in environment cause beneficial
mutations and natural selection.
• Natural selection results in perfection.
• Natural selection works toward reaching a
predetermined goal.
– Were Alloperla sp. stoneflies supposed to
evolve to become a brilliant green color?
– Were humans supposed to become the way
they are?

162. • If humans evolved from other animals,
what type of animals would they most
likely have evolved from?
– Apes

164. What defines a primate?
A primate is a mammal that has:
• Opposable thumbs
• Rotating shoulder joints
• Binocular vision

187. • If humans evolved from other animals,
what type of animals would they most
likely have evolved from?
– Apes
• If humans evolved from some type of
apes, what evidence should exist?
– Transition fossils
– Anatomical & embryological homologies
– Molecular & biochemical homologies
– Behavioral similarities?

193. What makes people special?

197. “It would disturb me more to
find out that life couldn’t be
started in a laboratory. If life
can’t be started somehow in
this physical world, then how
did I get here?”
- Dr. Henry Eyring