You can look at evolution through 2 lens
Evolution: Macro Lens
• Macroevolution generally refers to evolution
above the species level.
• Species=a reproductively isolated population
able to interbreed and produce fertile
offspring
• Mutation: Some “green genes” randomly
mutated to “brown genes” (although since
any particular mutation is rare, this process
alone cannot account for a big change in allele
frequency over one generation).
• Migration (or gene flow): Some beetles with
brown genes immigrated from another
population, or some beetles carrying green
genes emigrated
• Genetic drift: When the beetles reproduced,
just by random luck more brown genes than
green genes ended up in the offspring. In the
diagram at right, brown genes occur slightly
more frequently in the offspring (29%) than in
the parent generation (25%).
Genetic Drift affects small or large populations
more? Why?
Small Pop
Large Pop
• Natural selection: Beetles with brown genes
escaped predation and survived to reproduce
more frequently than beetles with green
genes, so that more brown genes got into the
next generation.
Q1
In Amish populations, the incidence of a certain
type of dwarfism is much higher than those of
other populations. What principle explains this?
A founder effect
B genetic drift
C natural selection
D sexual selection
Darwin’s Theory
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Variation in individuals
Competition
Death to those without an advantage
Differentiated reproduction
Pass traits to offspring
Fitness=more offspring=more fit
Evidence of evolution—fossils, embryos,
homologous structures, DNA
Q2: This picture illustrates what type
of selection?
A sexual
B disruptive
C directional
D stabilizing
Some phenotypes are selected FOR
and some AGAINST
Evidence for evolution
Comparative anatomy
Embryology
Biogeography
Fossil record
Molecular biology
Q3: The amino acid sequence of cytochrome c is exactly
the same in humans and chimpanzees. There is a
difference of 13 amino acids between the cytochrome c of
humans and dogs, and a difference of 20 amino acids
between the cytochrome c of humans and rattlesnakes.
Which of the following statements is best supported by
these data?
(A) Rattlesnakes apparently gave rise evolutionarily to the dog, chimpanzee, and
human.
(B) Cytochrome c apparently has an entirely different function in rattlesnakes than
in mammals, which explains the difference in the number of amino acids.
(C) Cytochrome c is not found universally in animals.
(D) Cytochrome c from a rattlesnake could function in a dog, but not in a
chimpanzee.
(E) The human is apparently more closely related to the chimpanzee than to the
dog or rattlesnake.
Q3: The amino acid sequence of cytochrome c is exactly
the same in humans and chimpanzees. There is a
difference of 13 amino acids between the cytochrome c of
humans and dogs, and a difference of 20 amino acids
between the cytochrome c of humans and rattlesnakes.
Which of the following statements is best supported by
these data?
• (A) Rattlesnakes apparently gave rise evolutionarily to the dog, chimpanzee,
and human.
• (B) Cytochrome c apparently has an entirely different function in rattlesnakes
than in mammals, which explains the difference in the umber of amino acids.
• (C) Cytochrome c is not found universally in animals.
• (D) Cytochrome c from a rattlesnake could function in a dog, but not in a
chimpanzee.
• (E) The human is apparently more closely related to the chimpanzee than to
the dog or rattlesnake.
Cladogram Review
Allopatric vs Sympatric Species
Evolution: Micro
• Microevolution is evolution on a small scale—
within a single population. That means
narrowing our focus to one branch of the tree
of life.
• You could continue zooming in until you saw
the relationships between beetle populations.
• We’ve defined microevolution as a change in gene frequency in a
population and a population as a group of organisms that share a
common gene pool
• Imagine that you go to the mountaintop this year, sample these beetles,
and determine that 80% of the genes in the population are for green
coloration and 20% of them are for brown coloration.
• You go back the next year, repeat the procedure, and find a new ratio: 60%
green genes to 40% brown genes.
Hardy Weinberg Review
• Population symbols—p2, 2pq, q2
• Allele frequency symbols—p and q
Look at what is given and what you have to solve
for
Q4
A survey reveals that 25% of a
population of 1000 have attached
earlobes, homo recessive trait.
What is the frequency of recessive
allele?__
What % are heterozygous?___
Q5: Which of the following factors is
the most effective in changing allele
frequency in natural populations?
A Large population size
B Low rate of mutation
C Negligable migration
D Random mating
E Selection
Q5: Which of the following factors is
the most effective in changing allele
frequency in natural populations?
A Large population size
B Low rate of mutation
C Negligable migration
D Random mating
E Selection
Q6: Evolutionary fitness is measured by
A. Physical strength
B.Reproductive success
C. Length of life
D. Resistance to disease
E. Competiveness
Q6: Evolutionary fitness is measured by
A. Physical strength
B. Reproductive success
C. Length of life
D. Resistance to disease
E. Compeitiveness
Q7: All of the following are examples
of prezygotic isolating mechanisms
EXCEPT:
A Male fireflies of different species have different flash
patterns
B Three closely related orchid species flower on different
days
C The progeny of a cross between two different lizard
species fail to develop properly
D One species of snake lives in water and another is
terrestial
E Pepper frogs mate in April, and tree frogs mate in June
Q7: All of the following are examples
of prezygotic isolating mechanisms
EXCEPT:
A Male fireflies of different species have different flash
patterns
B Three closely related orchid species flower on different
days
C The progeny of a cross between two different lizard
species fail to develop properly
D One species of snake lives in water and another is
terrestial
E Pepper frogs mate in April, and tree frogs mate in June
Q8: Two fossil vertebrates, each representing a
different class, are found in the undisturbed rock layers
of a cliff. One fossil is a representative of the earliest
amphibians. The other fossil, found in an older rock
layer below the amphibian, is most likely to be
(A) A dinosaur
(B) A fish
(C) An insectivorous mammal
(D) A snake
(E) A bird
Q8: Two fossil vertebrates, each representing a
different class, are found in the undisturbed rock layers
of a cliff. One fossil is a representative of the earliest
amphibians. The other fossil, found in an older rock
layer below the amphibian, is most likely to be
(A) A dinosaur
(B) A fish
(C) An insectivorous mammal
(D) A snake
(E) A bird
1. Appearance of terrestrial plants
2. Appearance of chloroplasts
3. Formation of complex organic compounds
4. Development of photosynthetic organisms
5. Development of anaerobic prokaryotes
Q9: From the list above, which is most likely
chronological order of events, from oldest to most
recent, in the history of the Earth?
A 1, 2, 4, 5, 3
B 3, 2, 5, 4, 1
C 3, 5, 4, 2, 1
D 5, 2, 3, 1, 4
E 5, 2, 4, 3, 1
1. Appearance of terrestrial plants
2. Appearance of chloroplasts
3. Formation of complex organic compounds
4. Development of photosynthetic organisms
5. Development of anaerobic prokaryotes
Q9: From the list above, which is most likely
chronological order of events, from oldest to most
recent, in the history of the Earth?
A 1, 2, 4, 5, 3
B 3, 2, 5, 4, 1
C 3, 5, 4, 2, 1
D 5, 2, 3, 1, 4
E 5, 2, 4, 3, 1
Q10: The different species of finches
on the Galapagos Islands are believed
to have arisen as a result of natural
selection acting on populations of
finches that had experienced
A convergent evolution
B gene flow
C the bottle neck effect
D geographic isolation
E hybrid sterility
Q10: The different species of finches
on the Galapagos Islands are believed
to have arisen as a result of natural
selection acting on populations of
finches that had experienced
A convergent evolution
B gene flow
C the bottle neck effect
D geographic isolation
E hybrid sterility
Q11: Adaptations that have enabled
vertebrates to survive on land include
all of the following EXCEPT:
A a water-resistant epidermis
B development of a bony skeleton
C development of lungs
D external fertilization
E embryos enclosed within membranes
Q11: Adaptations that have enabled
vertebrates to survive on land include
all of the following EXCEPT:
A a water-resistant epidermis
B development of a bony skeleton
C development of lungs
D external fertilization
E embryos enclosed within membranes
Q12: If organisms A, B and C belong to the same
order but to different families and if organisms
D, E and F belong to the same family but to
different genera, which of the following pairs of
organisms would be expected to show the
greatest degree of structural homology?
A
B
C
D
E
A and B
A and C
B and D
C and F
E and F
Q13: If organisms A, B and C belong to the same
order but to different families and if organisms
D, E and F belong to the same family but to
different genera, which of the following pairs of
organisms would be expected to show the
greatest degree of structural homology?
A
B
C
D
E
A and B
A and C
B and D
C and F
E and F