Evolutionary Biology Spring 2015 Study Questions
The following study questions are designed to help you think about the lecture material. They are not comprehensive questions. Exam material is NOT limited to the topics in study questions and will not follow this format.
Lecture 1 - Jan 20th 2015
1) What type of adaptation would you expect to see in an organism trying to survive in an environment with visual predators?
2) What’s one possible explanation for powered flight appearing only once in invertebrates and at least three times in vertebrates?
3) Why would it be advantageous for an organism to resemble something else; i.e. a caterpillar that looks like bird droppings or an orchid that smells like carrion?
4) What’s convergence? Can you think of an example we saw in lecture?
5) Do similar traits always evolve to solve the same challenges? For instance, are all brightly colored organisms just trying to get a mate?
6) In what ways can humans be a source of selection to other organisms?
7) What’s the difference between evolutionary change and phenotypic plasticity?
Lecture 2 - Jan 22nd 2015
1) Suppose you observe that the average weight of squirrels on campus is greater than their average weight on Horsebarn Hill. Describe how you would use a reciprocal translocation experiment to test the hypothesis that the difference in weight of squirrels on campus and on Hosebarn Hill is the result of an evolutionary change. Explain what outcome(s) would support this hypothesis. What outcome(s) would not support the hypothesis?
2) In class, we focused on figuring out how to tell if a phenotypic difference was caused by an evolutionary change. What if there's no phenotypic difference between two populations you observe in the wild--could there still have been an evolutionary change? Why or why not?
3) Why do we focus on genetic differences in studying evolutionary change?
4) What is the relationship between Mendelian genetics and population genetics?
5) What are the variables used to describe the genetic composition of a population?
6) In general terms, what genotype frequencies are expected under the Hardy-Weinberg equilibrium with 2 alleles? What do you think the proportions are going to be if we’re studying a locus with 3 alleles? Trying drawing one of those box diagrams we saw in class to support your answer.
7) What happens to genotype frequencies in a population under Hardy-Weinberg equilibrium in subsequent generations? What happens to allele frequencies?
8) Hardy-Weinberg practice: try the problems here to get practice with describing the genetic composition of a population and determining Hardy-Weinberg proportions.
9) Challenge Problem: What’s the highest frequency of heterozygotes that is expected under HWE for a locus with 2 alleles?
Don’t forget to finish Activity 2 – It should be handed in at the beginning of lecture on Thursday Jan. 29th.
Lecture 3 - Jan 29th 2015
1) Why do we use allele and genotypes frequencies instead of the number of gametes or individuals in a population?
2) How many generations does it take for a population to establish genotype frequencies in HWE (Hardy-Weinberg equilibrium) given all the assumptions are met?
3) In what situation do we need to assume Hardy-Weinberg equilibrium instead of testing for it? What information do we need in order to test for HWE?
4) HWE assumes that there is no new genetic mutations. However, all new genetic variation occurs through mutation. Why do we mostly ignore this assumption violation?
5) You observe the genotype frequencies of a cow population for 2 generations. The allele frequencies and genotype frequencies do not change. Is this population in HWE? Why or why not.
6) What happens to genetic variation, allele frequencies, and genotype frequencies as a result of inbreeding?
7) What are the different types of non-random mating?
8) How can you tell the difference between inbreeding and assortative mating?
9) What is the most extreme form of inbreeding?
10) What do you expect the effects of inbreeding would generally be on fitness? Why?
11) Why are inbred lines of model organisms (e.g. Drosophila, mice, C. elegans) often used in biomedical research?
12) Under what conditions would assortative mating cause evolution? Under what conditions would it not result in evolution?
13) Given what you know about the different types of non-random mating and their effects on genotype and allele frequencies, what would you expect to be the result of disassortative mating?
There are very good practice questions at the end of each chapter of the textbook. Try doing questions 1 through 5 at the end of Chapter 9 - page 255