1. Concept 53.1: Dynamic biological processes influence population density, dispersion, and demographics
  1. A ______is a group of individuals of a single species living in the same general area
  1. ______is the study of populations in relation to environment, including environmental influences on density and distribution, age structure, and population size
  1. ______is the number of individuals per unit area or volume
  1. ______is the pattern of spacing among individuals within the boundaries of the population
  2. In most cases, it is impractical or impossible to count all individuals in a population
  3. Sampling techniques can be used to estimate densities and total population sizes
  4. Population size can be estimated by either extrapolation from small samples, an index of population size, or the

______

  1. Environmental and social factors influence spacing of individuals in a population
  1. In a ______dispersion, individuals aggregate in patches
  2. A clumped dispersion may be influenced by resource availability and behavior
  1. A ______dispersion is one in which individuals are evenly distributed
  2. It may be influenced by social interactions such as

______

  1. In a ______dispersion, the position of each individual is independent of other individuals
  2. It occurs in the absence of strong attractions or repulsions
  1. Demography is the study of the vital statistics of a population and how they change over time
  1. ______ratesand ______

______ratesare of particular interest to demographers

  1. A ______is an age-specific summary of the survival pattern of a population
  1. A ______is a graphic way of representing the data in a life table
  2. Survivorship curves can be classified into three general types:
  3. Type I: low death rates during early and middle life, then an increase among older age groups

(______)

  1. Type II: the death rate is constant over the organism’s

life span (______)

  1. Type III: high death rates for the young, then a slower

death rate for survivors (______)

Lecture Questions53.1 Characteristics of Populations

  1. Describe conditions that may result in clumped dispersion, uniform dispersion, and random dispersion of individuals in a population.
  1. Describe the characteristics of populations that exhibit Type I, Type II, and Type III survivorship curves.
  1. Concept 53.2: Life history traits are products of natural selection
  2. An organism’s life history comprises the traits that affect its schedule of reproduction and survival:
  1. The ______at which reproduction begins
  1. How often the organism reproduces
  1. How ______offspring are produced during each reproductive cycle
  1. Life history traits are evolutionary outcomes reflected in the development, physiology, and behavior of an organism
  2. Life histories are very diverse
  1. Species that exhibit ______, or big-bang reproduction, reproduce once and die
  1. Species that exhibit ______, or repeated reproduction, produce offspring repeatedly
  2. Highly variable or unpredictable environments likely favor big-bang reproduction, while dependable environments may favor repeated reproduction

Lecture Questions 53.2 Life Histories

  1. Define and distinguish between semelparity and iteroparity. Explain what factors may favor the evolution of each life history strategy.
  1. Concept 53.3: The exponential model describes population growth in an idealized, unlimited environment
  2. It is useful to study population growth in an idealized situation

(ignoring______).

  1. We define a change in population size based on the following verbal equation.
  1. We can simplify the equation and use r to represent the difference in per capita birth and death rates.
  1. ______population growth is population increase under idealized conditions
  2. Under these conditions, the rate of reproduction is at its maximum, called the intrinsic rate of increase
  3. Equation of exponential population growth:
  1. Exponential population growth results in a J-shaped curve
  2. The J-shaped curve of exponential growth characterizes some rebounding populations
  1. Concept 53.4: The logistic model describes how a population grows more slowly as it nears its carrying capacity
  2. Exponential growth cannot be sustained for long in any population
  3. A more realistic population model limits growth by incorporating carrying capacity
  1. ______(K) is the maximum population size the environment can support
  2. In the logistic population growth model, the per capita rate of increase declines as carrying capacity is reached
  3. We construct the logistic model by starting with the exponential model and adding an expression that reduces per capita rate of increase as N approaches K
  4. The logistic model of population growth produces a sigmoid (S-shaped) curve
  5. The growth of laboratory populations of paramecia and daphnia fits an S-shaped curve.
  6. These organisms are grown in a constant environment lacking predators and competitors
  7. Some populations fluctuate greatly and make it difficult to define K
  1. Some populations show an ______

______, in which individuals have a more difficult time surviving or reproducing if the population size is too small

  1. Life history traits favored by natural selection may vary with population density and environmental conditions
  1. ______, or density-dependent selection, selects for life history traits that are sensitive to population density
  1. ______, or density-independent selection, selects for life history traits that maximize reproduction

Lecture Questions 53.3-53.4 Population Growth

  1. Compare the exponential model of population growth with the logistic model.
  1. Distinguish between r-selected populations and K-selected populations.
  1. Concept 53.5: Many factors that regulate population growth are density dependent
  2. There are two general questions about regulation of population growth:
  3. What environmental factors stop a population from growing indefinitely?
  4. Why do some populations show radical fluctuations in size over time, while others remain stable?
  1. In ______populations, birth rate and death rate do not change with population density
  1. In ______populations, birth rates fall and death rates rise with population density
  1. (______)
  2. Density-dependent birth and death rates are an example of negative feedback that regulates population growth
  3. They are affected by many factors, such as competition for

resources, ______, disease, predation,

______, and intrinsic factors

  1. Factors causing a negative feedback:
  2. In crowded populations, increasing population density intensifies competition for resources and results in a lower birth rate
  3. Territoriality, in many vertebrates and some invertebrates, competition for territory may limit density
  4. ______, in dense populations, pathogens can spread more rapidly
  1. ______-as a prey population builds up, predators may feed preferentially on that species
  2. Toxic Wastes-accumulation of toxic wastes can contribute to density-dependent regulation of population size (yeast in alcohol fermentation)
  1. For some populations, intrinsic (physiological) factors appear to regulate population size
  1. The study of population dynamics focuses on the complex interactions between biotic and abiotic factors that cause variation in population size
  2. Carrying capacity can vary
  3. Year to year data can be helpful in analyzing population growth.
  4. Long-term population studies have challenged the hypothesis that populations of large mammals are relatively stable over time
  5. Changes in predation pressure can drive population fluctuations
  6. Some populations undergo regular

______ cycles

  1. Lynx populations follow the 10 year boom-and-bust cycle of hare populations

Lecture Question 53.5 Population-Limiting Factors

  1. Explain, with examples, how biotic and abiotic factors may work together to control a population’s growth.
  1. Concept 53.6: The human population is no longer growing exponentially but is still increasing rapidly
  2. No population can grow indefinitely, and humans are no exception
  3. The human population increased relatively slowly until about 1650 and then began to grow exponentially
  4. To maintain population stability, a regional human population can exist in one of two configurations:
  5. Zero population growth =
  1. Zero population growth =
  1. The demographic transition is the move from the first state toward the second state
  2. One important demographic factor in present and future

growth trends is a country’s ______

______

  1. Age structure is the relative number of individuals at each age
  2. Age structure diagrams can predict a population’s growth trends
  3. They can illuminate social conditions and help us plan for the future
  1. How many humans can the biosphere support?
  2. The carrying capacity of Earth for humans is uncertain
  3. The average estimate is 10–15 billion
  1. The ______concept summarizes the aggregate land and water area needed to sustain the people of a nation
  2. It is one measure of how close we are to the carrying capacity of Earth
  3. Countries vary greatly in footprint size and available ecological capacity
  4. Our carrying capacity could potentially be limited by food, space, nonrenewable resources, or buildup of waste

Lecture Question 53.6 Human Population Growth

  1. Explain how an ecological footprint can be calculated for an individual or country. Describe the possible currencies of this calculation.