Download The Making of the Fittest - 5 Short Films Watch any 4 of the 5 short

Name:___________________________
The Making of the Fittest - 5 Short Films
Watch any 4 of the 5 short films listed below. These films were produced by the Howard Hughes Medical
Institute and feature examples of the evolutionary process in action. Answer the questions listed for each of
the four films that you watched. Questions and answers are due when you come to class tomorrow.
Video #1: Natural Selection and Adaptations
(http://www.hhmi.org/biointeractive/making-fittest-natural-selection-and-adaptation)
1. Is the following statement true or false? “The same mutation could be advantageous in some
environments but deleterious in others.” Justify your answer.
2. Explain how the environment plays a role in changing the frequency of a mutant allele in a population.
3. As you saw in the film, rock pocket mice evolved to have dark-colored fur in certain habitats. In three
to five sentences, explain how this trait increased in frequency in the population. Include the following
key terms: fitness (or fit), survival (or survive), selection (or selective), and evolution (or evolve)
4. Near the end of the film, Dr. Sean B. Carroll states that “while mutation is random, natural selection is
not.” In your own words, explain how this is possible.
Video #2: The Birth and Death of Genes
(http://www.hhmi.org/biointeractive/making-fittest-birth-and-death-genes)
1. Explain how a change in the environment can result in a change in the frequency of a gene in a
population.
2. Compare and contrast the process by which genes are born and the process by which genes die.
Include at least one way in which these two processes are the same, and one way in which they are
different.
3. Is the following statement true or false? “If the temperature of the environment where the icefish are
living were to rise to 5 C, the frequency of the antifreeze gene in the population would likely increase.”
Justify your answer.
4. In the film, you saw that icefish have evolved to thrive in extremely cold water. State two genetic
changes these fish have undergone to be able to thrive in this cold environment.
Video #3: Natural Selection in Humans
(http://www.hhmi.org/biointeractive/making-fittest-natural-selection-humans)
1. In three to five sentences, explain why sickle cell disease became so prevalent in certain East African
populations.
2. There are now several effective antimalarial drugs that can treat people who have malaria or prevent
them from getting the disease altogether. Predict what will happen to the frequency of the sickle cell
allele as three drugs become more widely used. Support your answer with at least one piece of
evidence from the film.
3. Is the following statement true or false? “Malaria caused the sickle cell allele to appear.” Justify your
answer.
Name:___________________________
Video #4: Evolving Switches, Evolving Bodies
(http://www.hhmi.org/biointeractive/making-fittest-evolving-switches-evolving-bodies)
1. What specific features of the environment in Bear Paw Lake, Alaska, may have favored the survival
and reproduction of stickleback fish with reduced pelvises? Answer in three to five sentences.
2. Scientists working in a different field and in a different organism (mice) first discovered the function of
the Pitx1 gene. To determine what the Pitx1 gene did, these scientists intentionally mutated the Pitx1
protein-coding region in mice so that the Pitx1 protein was no longer produced. These mice died
before birth and had miniaturized hind limbs.
a. What do you think these scientists concluded about the function of the Pitx1 protein after
carrying out this experiment?
b. How is the genetic change that occurred in stickleback fish with reduced pelvises in freshwater
lakes different from the one that scientists produced in the mice?
c. Why do you think stickleback fish with a Pitx1 mutation are able to survive but not the mice?
Video #5: Got Lactase? The Co-evolution of Genes and Culture
(http://www.hhmi.org/biointeractive/making-fittest-got-lactase-co-evolution-genes-and-culture)
1. Geneticists studying the gene for lactase did not find any differences in the coding region DNA (the
section of DNA with instructions to make the proteins) between people who could digest lactose and
people who could not digest lactose. After they investigated further, they discovered that the
difference between lactose tolerant and intolerant was due to ……. (explain in detail)
2. What discovery supports the hypothesis that evolution of the lactase persistence trait was driven by
the use of milk?
3. Why would measuring blood glucose levels in an individual, 20 t0 30 minutes after they drink a liter of
milk, indicate whether they are able to digest lactose?