Revision of populations

Question 1

Properties of Populations

Answer 1

• Organisms may be unitary or modular
• The distribution of a population defines its spatial location
• Abundance reflects population density and distribution
• Determining density requires sampling
• Populations have age structures and gender ratios
• Population distribution and density change in both time and space

Question 2

Population Growth

Answer 2

• Population growth reflects the difference between rates of birth and death
• Life tables provide a schedule of age-specific mortality and survival
• Different types of life tables reflect different approaches to defining cohorts and age structure
• Life tables provide data for mortality and survivorship curves
• Birth rate is age-specific
• Birth rate and survivorship determine net reproductive rate
• Age-specific mortality and birth rates can be used to project population growth
• Stochastic processes can influence population dynamics
• A variety of factors can lead to population extinction
• Small populations are susceptible to extinction

Question 3

Life History Strategies

Answer 3

• The evolution of life histories involves trade-offs
• Reproduction involves both benefits and costs to individual fitness
• Age at maturity is influenced by patterns of age-specific mortality
• Reproductive effort is governed by trade-offs between fecundity and survival
• There is a trade-off between the number and size of offspring
• Species differ in the timing of reproduction
• Mating systems describe the pairing of males and females
• Acquisition of a mate involves sexual selection
• An individual’s life history represents the interaction between genotype and the environment
• Patterns of life history characteristics reflect external selective forces.

Question 4

Population Regulation

Answer 4

• The environment functions to limit population growth
• Population regulation involves density dependence
• Competition results when resources are limited
• Intraspecific competition affects:
  A) growth and development
  B) mortality rates
  C) reproduction
• High density is stressful to individuals
• Dispersal can be density dependent
• Social behavior may function to limit populations
• Territoriality can function to regulate population growth
• Density-independent factors can also influence population growth