Name _______________________________

BIOL 430                                                        Exam I                                                             9/29/99

In each section, use only the space provided.  This exam is worth 125 points, 1/8 of your class grade.  You have 50 minutes.  Allocate your time wisely.

A.            Multiple choice.  Choose by circling the most correct answer for each question, unless otherwise specified.  10 questions, 6 points each = 60 points.

1.      What information do you need to know in order to calculate an animal's inclusive fitness?

1. The number of offspring it has.
2. The genetic relatedness of the animal with all others in the population.
3. The genetic relatedness of the animal with others, the number of offspring others have, and the number of offspring the animal has.
4. The genetic relatedness of all the offspring the animal has, the number of offspring the animal has, and the number of offspring other animals have.

2.      Extinction

1. is a natural process.
2. rates have increased in the last century.
3. is the loss of biodiversity.
4. is all of the above and more.

3.      How can genetic drift lead to evolution in a population?

1. Random mating in a small population can lead to allele frequency changes by favoring certain alleles.
2. Random mating in a small population can lead to allele frequency changes by chance.
3. By selecting for individuals that have the drift gene.
4. By causing certain individuals to disperse further than others.

4.      Natural selection

1. has a purpose.
2. is the differential, nonrandom survival of individuals with variation in particular traits.
3. was outlined by Charles Darwin from evidence he collected on DNA sequences.
4. is caused by the struggle for plentiful resources by individuals that vary in their ability to acquire those resources.

5.      Why do most species of mammals have polygynous mating systems?

a.      Because females disperse further than males and aggregate in one male's territory.

b.      Females can increase their reproductive success by sharing the male.

c.   Males can desert the female, especially if it is likely that he will find another mate.

d.      Because mammals typically live in stable habitats, where polygyny is advantageous.

6.      Bet-hedging might be a good reproductive strategy to adopt

a.   in variable environments.

b.   when juvenile survival is high.

c.   in predictable environments.

d.   by semelparous populations.

7.      The ideal free distribution is

a.   the sharing of resources and the distribution of individuals based on territories.

b.   the sharing of resources and the distribution of individuals based on resource availability.

c.   the fight for resources and the distribution of individuals based on territories.

d.   the fight for resources and the distribution of individuals based on resource availability.

8.      Pioneer plant species that are r-selected would be predicted to have which of the following characteristics?

a.   Slow growth in a variable environment.

b.   High reproductive rate in a constant environment.

c.   Small body size and high dispersal in a variable environment.

d.      Repeated reproduction and high competitive ability in a variable environment.

9.      For population growth models studied in lab and lecture, circle all of the following that are true

a.   r = the per capita, instantaneous rate of population growth

b.   the finite rate of increase, l = r

c.   density dependence is represented by [(K-N)/K]

d.   the fecundity schedule allows calculation of age-structured growth

e.   R₀ = SrN

f.    a sigmoid curve results from dN/dt = rN

g.   a time lag may cause a population to overshoot its carrying capacity

10.  Circle all of the following that are true.

1. A prezygotic isolating mechanism is one in which fertilization takes place, but hybrids are sterile.
2. Allopatric speciation is thought to be a major mechanism of speciation because populations are separated geographically.
3. One species can give rise to multiple new species or it can simply change over time into one new species.
4. When diversity tends to increase over time, extinction rates must be greater than speciation rates.
5. Biodiversity can only be measured by the total amount of genetic variation present on Earth.
6. Ethological isolating mechanisms keep two populations (or species) separated genetically through varying mating seasons.

B.         Short Answer: Use only the space provided below each question to answer (30 points total).

1.      List three specific factors that may limit the distribution or abundance of a species (10 points).

2.      Briefly discuss one major point of the article by Ehrlich and Raven, The "balance of nature" and "population control" regarding "The World is Green Hypothesis" of Hairston, Smith, and Slobodkin (10 points).

3.      Discuss the problem of taxonomy, that is, the naming and describing of new species, and how it relates to the field of ecology (10 points).

C.        Outline of an essay (40 points). Use the space on the back to answer.  Do not write an essay; simply make an outline, as the first step in writing an essay.  The essay will come later, as your first writing assignment.

Consider that you are a conservation biologist concerned with conservation of a large mammalian predator, the Sabre-Toothed Cat (Smilodon fatalis).  Discuss four life history characteristics that you would need to know for this species in order to set up a Sabre-Toothed Cat conservation program.  For each characteristic, identify why it would be important for this conservation program and predict what that characteristic might be for a large mammalian predator.  For instance, if you facetiously discuss teeth as one of your life history characteristics, you might predict that the characteristic type of teeth might be sharp relative to other species (not a life history characteristic, just an example).

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