Answers to page 346#1-10

  1. Mathus predicted that the human population would outgrow food supply by the mid-19th century and Cornucopians promote more the view of more is better. The will find solutions to food shortages.
  2. False- They thought about this back to the ancient Greek time and delayed age of marriage for men to 30.
  3. Biological Population is a group of organisms of a single species living within a certain area.
  4. Total number of individuals is less meaningful than the population density of individuals or the number of individuals per area or volume. Use population density for comparison over space or time.
  5. MVP is the smallest number of individuals that can exist without extinction due to random catastrophic variations in environmental, reproduction, or genetic diversity. PVA population viability analysis is a model of interactions between a species and the resources which it depends. PVA can predict the probability of extinction, focus conservation efforts, and guide plans for sustainable management.
  6. Patch distribution is scattered suitable areas within population boundaries of individuals within a population. The spacing of individuals within a population is dispersion.
  7. The age-sex structure. This shows the health of the population. Shows the birthrate and death rate.
  8. The offspring in delayed reproduction will not have as many offspring as the early reproduction offspring.
  9. Type I- few offspring, low death rate, live their entire lifespan, Type II- moderate death rate, individuals die at any age all the time, ex. Coral, Type III- high death rate, high birth rate example mayflies.
  10. Human population is in Type I survivorship curve, tend to have high population density. In this area population increases expodentially.

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2. J- curve is when there is exponential growth only under ideal conditions. The population has to grow in order to have the population exponentially grow. With the S-curve the growth rate is proportional to the size of the population but also to the amount of available resources. At higher population densities, limited resources lead to competition and lower growth rates. Eventually, the growth rate declines to zero and the population becomes stable. This happens in a realistic setting.

6. Dispersal moves offspring away from parents and it reduces intraspecific competition. An example would be moving offspring of wolves to a different geographical location, or spawning salmon. Migration is seasonal movement of population that can affect all four components of population growth. Ex would be migratory monarch butterflies, or geese.

7. The maximum population size that the environment can support and not suffer any degradation in the environment. This is basically where the population death rate is equal to its birth rate.

8. Density-dependent limiting factors lower birth rates or increase death/emigration rates via increased intraspecific competition at higher population densities. Density-independent factors, such as rainfall, drought, or pollution, can also limit populations, but they seldom regulate populations because they act irregularly, regardless of the population densities.

9. In predator/prey cycles the predator is always trailing the prey. So, when there is an increase in prey population there will be an increase in predator population. Density-population controls depends on the amount of resources that is available because the more resources the more the population will grow and the less resources the more intraspecific competition there is and therefore the population will be controlled by that.