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If a mutation appears in one individual that changes one base in a DNA sequence to another base, and the population is evolving by genetic drift, over time that mutation will:
Always take over and displace the old sequence. Disappear half the time and completely displace the old sequence half the time. Disappear most of the time. Always disappear.
Q2. When a DNA sequence is mutated, the individuals with that mutated sequence must also:
Have corresponding changes in some trait like size or color. Be in a different population from the individuals with the older sequence. All have the same mutation at the same time. A mutation in a DNA sequence doesn't imply anything else about that individual.
Q3. To determine how related two wolves are using DNA sequences, you would look for a sequence that:
Has very little or no selection on any position in the sequence. Has certain positions in the sequence that are under selection. Is under strong selection, so some mutations lead to better survival than others. Is directly related to a trait like size or color that you can see.
Q4. Using the method from this lab, what would be the genetic distance between Dog 1 and Dog 2 based on the following DNA sequences taken from the same place in each dog's DNA?
Dog 1: GGGGCCCC
Dog 2: GGGAACCC
Q5. If you measured the average size of individuals in many dog and wolf populations around the world, how would you use this to determine where and when dogs were domesticated from wolves?
You would use the UPGMA or similar technique with the size differences between dogs in the different populations. You would rank the dog populations from smallest to largest to give relatedness. You could not determine the relationships among dog populations using size because size changes quickly based on the environment around each population. You could not determine the relationships among dog populations using size because you can only determine population relationships using DNA sequences.
Q6. What pattern of relatedness would you infer among four individuals based only on the following sequences from the same place in their chromosomes?
D1: AAAATTTT
D2: AAACTTTT
D3: ACCCTTTT
D4: CCCCGGTT
D1 and D2 are most closely related. D1/D2 are in turn most closely related to D3, and D4 is the least related to the others. D1 and D2 are closely related. D3 and D4 are also closely related. D1/D2 are more distantly related to D3/D4. D1 and D3 are most closely related. D1/D2 are in turn most closely related to D2, and D4 is the least related to the others. D1 and D3 are closely related. D2 and D4 are closely related. D1/D3 are more distantly related to D2/D4.
Q7. What pattern of relatedness would you infer between the following individuals based just on these sequences?
D5: AAAATTTT
D6: AAACTTTT
D7: AGGCTTTC
D8: AGGGTTTT
D5 and D6 are most closely related. D5/D6 are in turn most closely related to D7, and D8 is the least related to the others. D5 and D6 are closely related. D7 and D8 are also closely related. D5/D6 are more distantly related to D7/D8. D5 and D7 are most closely related. D5/D7 are in turn most closely related to D6, and D8 is the least related to the others. D5 and D7 are closely related. D6 and D8 are closely related. D5/D7 are more distantly related to D6/D8.
Q10. From the evolutionary tree for dogs and wolves in the lab workbook (Exercise 6: Wolves and Dogs), how many times do you infer that dogs were domesticated from wolves?
None; dogs were domesticated from coyotes Once More than once
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1)Below are two histograms showing guppy coloration in two different streams, Stream North and Stream South. Use these histograms to answer the first two questions.
Q1. Which spot brightness level is most heavily represented in Stream North?
Q2. In which stream is average spot brightness highest: Stream North or Stream South?
Stream North.
Stream South.
Q3. Darwin's theory of natural selection is based on which of the following assumptions? (Check all that apply.)
Variability
Inheritance
Differential survival
Sexual reproduction
Q4. Which of the following options best summarizes Endler's greenhouse pond experiment? Variation in adult male coloration among ponds was due to:
The populations initially having different coloration.
Differences in the hunting patterns of predators.
The loss of spots in some populations due to a mutation.
Variable preferences by female guppies causing divergent sexual selection.
Q5. Fill in the blanks in the following sentence by selecting an option from below. Cichlids tend to prey on ______________ guppies, while Rivulus mainly prey on _____________ guppies.
Adult; juvenile
Juvenile; adult
Male; female
Female; male
Q6. Which of the following locations was not indicated as part of the natural range of guppies, Poecilia reticulata?
Venezuela.
Trinidad.
Tobago.
Columbia.
Q7. In Endler's study, after 20 months, what was the average number of spots on fish in the control pond?
10
11
12
13
Q8. Which of the following best describes the change in coloration observed in male guppies?
A mutation in the male guppies occurred when predators were present.
The male guppies change their coloration when they see a predator.
Male guppies with more showy coloration tend to be eaten more often.
When females are in the presence of predators, they tend to give birth to less showy male guppies.
Q9. Imagine a different system in which toads had a wide range of variation in color. In some ponds, most of the toads are light in color. In other ponds, the average color is fairly dark. From the options below, select which represent TESTABLE hypotheses that could explain this difference in coloration. (Check all that apply.)
A predator that is present in some ponds prefers one color to the other.
Female toads in some ponds prefer darker toads, while females in another pond prefer lighter toads.
Toad color is determined by food quality, which varies pond to pond.
Toads can change their color, based on their stress level.
Q10. An evolutionary biologist studying the toads in Question 9 hypothesizes that female toads prefer like-colored mates, and this preference maintains observed variation in toad color among ponds. Such mating is called assortative; in this case it would mean that light-colored females prefer light-colored males, and dark-colored females prefer dark-colored males.
The biologist has already determined that color is highly heritable for these toads. She rears toads in experimental tanks with no predators, over many generations, holding food quality constant. Which observation below best REFUTES her hypothesis?
A tank initially containing light and dark toads of both genders eventually contains only dark toads.
A tank initially containing light-colored females and males of both colors eventually contains only dark toads.
A tank initially containing dark-colored females and males of both colors eventually contains only dark toads.
A tank initially containing light-colored females and dark-colored males eventually contains toads of intermediate coloration.
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