age distribution 132
biotic potential 134
birthrate 131
carrying capacity 135
death phase 136
death rate 131
density-dependent limiting
      factors 138
density-independent limiting
      factors 138
dispersal 133 		emigration 133
environmental resistance 135
exponential growth phase
      (log phase) 134
immigration 133
K-strategists 138
lag phase 134
limiting factor 135
log phase 134
mortality 131 		natality 131
population density 133
r-strategists 138
sex ratio 132
stable equilibrium phase 135

On-line Flashcards
      What is causing the snow goose population to increase so quickly? What are the consequences of this rapid population growth? Take a look at Snow Goose Population Threatens Arctic Tundra Habitat for this story.
      The European green shore crab is also making its mark with increased population growth. This non-native (invading) species has been compared to the European zebra mussel and is causing problems for West Coast (U.S.) fisheries. For the entire story, read the Invasive Marine Species case study. 		      Increased population is not always gloom and doom. Two examples of population growth resulting from the restoration and protection of species are found in Pennsylvania's Elk Herd Growing and Positive Turn in Kenya's Rhino Population.
      What are your thoughts about managing elephant populations? Should they be managed through harvest or birth control? For more information about the legality of using elephant products, look at Ban on Wild Elephant Products Is Maintained.
Why is it getting so crowded? When a population is growing exponentially, it happens fast! See a bacteria population go through the stages of growth in Exponential Population Growth.
Review Questions
  1. How is biotic potential related to the rate at which a population will grow?
  2. List three characteristics populations might have.
  3. Why do some populations grow? What factors help to determine the rate of this growth?
  4. Under what conditions might a death phase occur?
  5. List four factors that could determine the carrying capacity of an animal species.

  1. How do the concepts of birthrate and population growth differ?
  2. How does the population growth curve of humans compare with that of bacteria on a petri dish?
  3. How do r-strategists and K-strategists differ?
  4. As the human population continues to increase, what might happen to other species?
  5. All successful organisms overproduce. What advantage does this provide for the species? What disadvantages may occur?
Critical Thinking Questions
  1. Why do you suppose some organisms display high natality and others display lower natality? For example, why do cottontail rabbits show high natality and wolves relatively low natality? Why wouldn't all organisms display high natality?
  2. Do you think African elephants should be managed by southern African countries like deer are managed in the United States? What values, beliefs, and perspectives lead you to your conclusion?
  3. Where do you stand on the issue of birth control for elephants or culling of the herd? Why do you think the way you do? What is the position of the Humane Society in the United States? Why do you think they hold the position they do? Do you think conservationists in the United States should have a say over what is done with the elephants in Africa? Should Africans have a say in what is done in the United States? Why?
  1. Consider the differences between r-strategists and K-strategists. What costs are incurred by adopting either strategy? What evolutionary benefits does each strategy enjoy?
  2. Why do invading species, which can survive in a new environment, often show exponential growth rates soon after they are introduced to that environment?
  3. If humans see that a population of organisms, like the population of wolves on Isle Royale, is declining for "natural" reasons, should humans intervene and try to preserve these populations? Why?