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.

Q1In Amish populations, the incidence of a certain

type of dwarfism is much higher than those of other populations. What principle explains this?

A founder effectB genetic driftC natural selectionD sexual selection

Darwin’s Theory• 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 sexualB disruptiveC directionalD stabilizing

Some phenotypes are selected FOR and some AGAINST

Evidence for evolution

Comparative anatomyEmbryologyBiogeographyFossil recordMolecular 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 sizeB Low rate of mutationC Negligable migrationD Random matingE Selection

Q5: Which of the following factors is the most effective in changing allele frequency in natural populations?

A Large population sizeB Low rate of mutationC Negligable migrationD Random matingE Selection

Q6: Evolutionary fitness is measured by

A. Physical strengthB.Reproductive successC. Length of lifeD. Resistance to diseaseE. Competiveness

Q6: Evolutionary fitness is measured by

A. Physical strengthB. Reproductive successC. Length of lifeD. Resistance to diseaseE. 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 terrestialE 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 terrestialE 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 plants2. Appearance of chloroplasts3. Formation of complex organic compounds4. Development of photosynthetic organisms5. 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, 3B 3, 2, 5, 4, 1C 3, 5, 4, 2, 1D 5, 2, 3, 1, 4E 5, 2, 4, 3, 1

1. Appearance of terrestrial plants2. Appearance of chloroplasts3. Formation of complex organic compounds4. Development of photosynthetic organisms5. 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, 3B 3, 2, 5, 4, 1C 3, 5, 4, 2, 1D 5, 2, 3, 1, 4E 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 evolutionB gene flowC the bottle neck effectD geographic isolationE 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 evolutionB gene flowC the bottle neck effectD geographic isolationE hybrid sterility

Q11: Adaptations that have enabled vertebrates to survive on land include all of the following EXCEPT:

A a water-resistant epidermisB development of a bony skeletonC development of lungsD external fertilizationE embryos enclosed within membranes

Q11: Adaptations that have enabled vertebrates to survive on land include all of the following EXCEPT:

A a water-resistant epidermisB development of a bony skeletonC development of lungsD external fertilizationE 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 A and BB A and CC B and DD C and FE 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 A and BB A and CC B and DD C and FE E and F