15
NAME______
BOX #______
BIOLOGY 101 MIDTERM EXAM
(POPULATION ECOLOGY and EVOLUTION)
CLOSED BOOK, OPEN MIND
THE HONOR SYSTEM PREVAILS.
50 MINUTES MAXIMUM TIME
1. CHECK EXAM TO BE SURE YOU HAVE all PAGES, NO OMISSIONS, NO DUPLICATIONS.
2. WRITE YOUR NAME AND BOX # ON EACH EXAM PAGE. (They are separated for grading.)
3. ANSWER QUESTIONS WITHIN THE SPACE ALLOCATED -- DO NOT WRITE ANSWERS ON BACK OF PAGE.
4. A BLANK IS CONSIDERED AS "NO KNOWLEDGE" AND NOT "NO TIME."
5. THERE ARE SOME CHOICES. DO NOT DO ALL QUESTIONS. CIRCLE THE QUESTIONS YOU WANT GRADED. FAILURE TO DO SO WILL RESULT IN FIRST ANSWERS BEING TAKEN AS YOUR CHOICES.
IF YOU HAVE QUESTIONS OR PROBLEMS, PLEASE SEE DR. KAPLAN. B212; ext. 7877
EXAM MUST BE RETURNED NO LATER THAN 5:00 PM TO THE BOX IN THE VOLLUM LECTURE HALL.
Part I. Laboratory Skills (3 minutes each)
A. How many stickleback sites did the class work this semester? ______
B. How many traps were put at each site during each sampling effort? ______
C. How many times per week was each site fished? ______
D. Assuming both weeks were identical in effort, how many total traps were thrown into the canyon this semester? ______
E. If we caught 9 fish on average per trap, how many total fish did we catch this semester?______
1. A linear regression of logarithmically transformed standard lengths and spine length fish data immediately allow us to examine the slope of the linear relationship of the logarithms and determine if the animal’s shape is isometric, positively allometric, or negatively allometric. What is the critical value of the slope that distinguishes these three shape features?
2. An experimental design that allows you to perform a two–way Analysis of Variance allows you to test what kind of hypothesis that would be inaccessible if your design only allowed you to perform two one-way Analyses of Variance?
3. For the tadpole experiment - Draw the experimental design in a 4 x 4 table and the physical design for one class in another 6 x 4 table. What is the total sample size? How were the statistical elements distributed into the physical design?
1) Stochastic extensions of deterministic growth models:
a) result in chaotic behavior;
b) make the model less realistic;
c) make the model easier to work with;
d) require the use of values that are drawn from a random distribution.
2) A population that grows sigmoidally is generally regulated in:
a) a way that results in an overshooting of the carrying capacity;
b) a density-independent manner;
c) a density-dependent manner;
d) an asymmetrical manner.
4) The size of the human population:
a) will not increase beyond the year 2000;
b) is 2 billion heading to 5 billion by the year 2100;
c) need not be regulated;
d) is 6.5 billion heading to 10 billion within 40 years.
5) The intrinsic rate of increase and the net reproductive rate:
a) vary in opposite directions;
b) can be both positive and negative;
c) apply to age structured populations only;
d) both describe populations that are growing when their values are greater than 1.0.
6). Symbiosis refers to
a) all interspecific interactions
b) the harmony of nature
c) those interactions where each species requires the other for its existence
d) the balance between intraspecific and interspecific interactions.
7) Genetic drift
a) increases with an increase in population size;
b) does not promote evolution;
c) results in increased heterozygosity;
d) results in increased homozygosity.
INSTRUCTIONS FOR ODD-MAN-OUT QUESTIONS: PUT AN X NEXT TO THE ONE THAT DOESN'T BELONG. WRITE A GOOD SENTENCE ABOUT WHY IT DOESN'T BELONG. THEN WRITE ANOTHER GOOD SENTENCE ABOUT WHY THE OTHER THREE ITEMS BELONG TOGETHER. EXAMPLE:
0.____LIZARD
____SNAKE
_X_PLATYPUS
____CROCODILE
A PLATYPUS IS A MAMMAL WITH HAIR AND MAMMARY GLANDS DESPITE ITS UNUSUAL QUALITY OF LAYING EGGS. THE OTHER THREE ALL BELONG TO THE CLASS OF VERTEBRATES CALLED REPTILES
1. ____conditions vs. resources
____abiotic vs. biotic
____external environment vs. internal environment
____adaptation
______
3. ____morphology
____physiology
____intrinsic rate of increase
____behavior
______
4.____stochastic model
____deterministic model
____exponential model
____logistic model
______
5. ____neutral theory
____selection theory
____niche theory
____neo-Darwinian theory
______
1. ____Carrying Capacity
____rmax
____rrealized
____biotic potential
2. ____survivorship curve
____lx
____life table
____mx
______
7. ____dorsal hollow nervous system
____external surface
____notochord
____pharyngeal gill clefts
______
Part IV. CHOOSE EITHER 1 or 2. NOT BOTH!!!!!!! TAKE 10 MINUTES
1)
a) Which species shows a curve that is typical of a majority of invertebrate species?
b) Which species shows a survivorship curve that most closely approximates one in which mortality rates are nearly constant throughout life? How might the graph be improved to show this more clearly?
c) How might you explain the characteristics of the Dall mountain sheep curve during the first year of life?
2) Using the graph above answer the following questions:
a) If a population starts off with the frequency of a particular allele at 0.3 and a population size of 10, approximately how long would you expect it to take for the number of heterozygotes in the population to reach 0%.
b) If a population of individuals is in a binomially expected distribution at a one gene locus two allele system and the frequency of one of the homozygote genotypes is 0.09, how long would you expect it would take for homozygosity to go to 100% if the population were reduced to a size of 5.
c) If a new mutation appeared in a population with 10 individuals that didn't change size, what are the chances that the new mutation would be lost from the population?
d)What are the chances that the new mutation would become fixed in the population?
CHOOSE EITHER 3 or 4 NOT BOTH (9 MINUTES)
3) What is Ro ? Is the following population of females shrinking, growing, or staying the same size? What assumption must you make to answer the question?
LIFE TABLE
age number surviving out of 1000
0 1000
1 800
2 400
3 200
4 0
FECUNDITY SCHEDULE
age number of births expected per females of various ages
0 0
1 0.5
2 1
3 0.5
4 0
(Show calculation for credit.)
1) Draw a graph that shows the difference between the outcome of natural selection operating in a one gene locus two allele model where the adaptive value for the heterozygote is higher than the homozygotes vs. lower than the homozygotes:
2) Draw a graph which shows the relationship between population size and the time to fixation or loss of an allele from a population:
3) Draw a diagram of a stable age distribution that is characteristic of a declining population:
4) Draw a graph of a survivorship curve that is indicative of a majority of large vertebrates:
5) What is the genotype-phenotype schism? ______
______
______
8) What is difference between density-dependent and density-independent population size regulation? ______
______
9) Give a real example of genetic structure of a population varying over space. ______
______
10) What are three ways in which genetic variability in a population can be measured?
______
______
12) "We have all evolved over three billion years by a process known as natural selection." Do you agree or disagree? Give two reasons to support your position. ______
______
______
13) The Analysis of Variance was developed by Sir Ronald Fisher. In what two ways did we make use of it? ______
______
Part II. Circle the letter (a, b, c, or d) that contains the best answer. (1 point each; 15 minutes)
1) Scientific theory is a) a body of knowledge meant to explain seemingly unrelated facts; b) an hypothesis about the outcome of a particular experiment; c) a model that results in particular hypotheses; d) basically good old-fashioned common sense.
2) A population that grows sigmoidally is generally regulated in: a) a way that
results in an overshooting of the carrying capacity; b) a density-independent
manner; c) a density-dependent manner; d) an asymmetrical manner.
3) Niche breadth and overlap:
a) require a stable age distribution
b) depend on the relationship between Darwinian and neutral theory
c) require small populations in order to function
d) are concepts used in the construction of community theory
4) Which of the following is not correct. Carrying capacity: a) refers to the ability of the environment to "carry" individuals; b) is constant in real populations; c) probably varies with fluctuations in the environment; d) is difficult to estimate.
5) Stochastic extensions of deterministic growth models: a) result in chaotic behavior; b) make the model less realistic; c) make the model easier to work with; d) require the use of values that are drawn from a random distribution.
6) The intrinsic rate of increase and the net reproductive rate a) vary in opposite directions; b) can be both positive and negative; c) apply to age structured populations only; d) both describe populations that are growing when their values are greater than 1.0.
7) A life table contains information about: a) the probability of death from one age to the next; b) population size; c) reproductive potential; d) resource utilization.
8). Symbiosis refers to a) all interspecific interactions b) the harmony of nature c) those interactions where each species requires the other for its existence d) the balance between intraspecific and interspecific interactions.
9) The size of the human population a) will not increase beyond the year 2000;
b) is 2 billion heading to 5 billion by the year 2100; c) need not be regulated;
d) is 5.0 billion heading to 10 billion within 40 years.
11) Selection favoring heterozygotes with selection coefficients of 0.5 and 0.3 against the two homozygotes, respectively will result in: a) a stable equilibrium at an allele frequency of 0.5; b) an unstable equilibrium at an allele frequency not at 0.5; b) a loss of genetic variation from the population; d) a stable equilibrium at an allele frequency other than 0.5.
13) Genetic drift a) increases with an increase in population size; b) does not promote evolution; c) results in increased heterozygosity; d) results in increased homozygosity.
14) A population that has genotype frequencies of 0.50 AA, 0.20 Aa and 0.30 aa a) will have a frequency of 0.36 AA when it comes to equilibrium; b) is at equilibrium; c) will have a frequency of A of 0.5 at equilibrium; d) is undergoing selection against the a allele.
15) In a cross between an Aa female by an Aa male: a)the ratio of heterozygotes to
homozygotes will be 1:1 b) AA and Aa offspring will be indistinguishable;
c) the ratio of homozygotes to heterozygotes will be 1:2; d) there will be equal numbers of all genotypes.
3) On the lower of the two graphs plot the behavior of the intrinsic rate of increase as a function of population growth patterns shown in the upper graph:
5) List 3 structural and 3 functional aspects of a population from both an
ecological and genetic perspective:
structure function
a) ecological
b) genetic
2) The above graph contains data that you need. It accurately describes the numbers of lynx populations in Canada.
If a biologist was studying the lynx population for five years between 1900 and 1905, is it possible that the following life and fecundity schedule captures the relevant values?
age proportion surviving out of 1000 fecundity
0 1.0 0
1 0.8 0
2 0.4 1
3 0.2 3
4 0.0 0
What assumption must you make to answer the question?
(Show all work for partial credit.)
PART II. Using the graph above answer the following questions (20 pts out of 100 pts ):
a) What is being plotted along the x- axis?______
What is being plotted along the y- axis?______
b) What is the expected frequency of homozygotes for the least common allele when the least common allele has a frequency of 30% and we assume no mutation, no migration, no natural selection, random mating and a population that is very large?
c) If 10 melanistic red-backed salamanders migrated into a region where 90 red-backed salamanders lived; and random mating ensued for a few generations; and population size stayed constant; and color was determined by a single gene locus that was homozygous in both initial populations, what would the final allele frequency be assuming no natural selection, random mating, no genetic drift, and no new mutations?