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Biology 315 Lecture Final

Most of the questions on this exam can each be answered in a single short paragraph. Answers will be evaluated on the basis of accuracy, completeness, logic, conciseness, synthesis of information, and integration of details with the big picture. Partial credit may be given for answers that are partially correct or show internally consistent logic. Conversely, a technically correct but trivial answer will receive less than full credit. Well-constructed, complete sentences are expected. Answers with serious grammatical and spelling errors or very poor handwriting may result in lowering of the grade.

1. How many full sisters would a bee have to sacrifice itself for to increase its inclusive fitness?

2. Given the following cohort life table and age vector construct a Leslie Matrix. Remember that this life table and the Leslie Matrix track females only. Then project the age distribution one year into the future. Is this population at an age distribution equilibrium? Is the total population size increasing, decreasing or constant?

Age x	Px	fx	Current State Vector
1	.2	.5	100
2	.5	.5	20
3	.4	.5	20

3. Two hypothetical species (A and B) are competing for light and soil nitrogen in a homogenous environment. A is a superior competitor for light, and B is an inferior competitor for nitrogen. Can these species coexist? If the intrinsic rate of natural increase (r₀) was increased substantially for A, would B be able to persist?

4. The current forest composition on Simple Island is defined by the state vector:

1. white oak	50
2. red maple	50

The 50 year transition probabilities are provided in the from column to row transition matrix:

	1	2
1	.50	.50
2	.50	.50

Provide the expected state vector after 50 years and after 100 years:

Is this system at equilibrium?

What is the probability of transition from white oak to red maple?

Red maple is dioecious and exhibits unequal sex ratios. Assume that exactly 70% of the red maples are male. What is the effective population size after 100 years? What is the expected fixation index? Do you expect an increase or a decrease in homozygosity?

5. Criticize the following food web of an aquatic ecosystem.

Osprey

large mouth bass

bluegill

invertebrates grass carp

plants

6. Cotton mouse weight is normally distributed. You want to know if cotton mice weigh more in clearcuts, selectively logged forests, or unlogged forests. State a hypothesis and a null hypothesis regarding your observation. Design a field study to test your hypothesis. State the statistical test that you would choose to test the hypothesis. State how you would interpret the results of your test.