Module 4 (Exam 1)

• niche: ecological role of organism, has habitat requirements
• environmental niche: includes abiotic (non-living) and bioitic (living) components of environment
• adaptive decision making is a result of natural selection
• natural selection allows for altruistic behaviors
• kin selection in prairie dogs:

  • more likely to alert to predator when close relatives are nearby
  • increases fitness by allowing more offspring to survive
• how can herbivory benefit plants?

  spread seed
• predation changes with prey population size, prey adaptations depend on predation levels
• keystone predators have a large impact on surrounding species
• competition occurs when niches overlap
• interference competition: one species directly denies or reduces access to resource
• competitive exclusion: niches completely overlap, weaker competitor can go extinct
• an organism with a greater niche range can self-limit to avoid being outcompeted
• exploitative competition: one species reduces abundance of resource
• species diversity is greatest at the equator, decreases as latitude increases
• why is species diversity greatest at the equator?

  • higher productivity (higher rainfall, continuous sunlight)
  • more layers/habitat complexity, more ecological niches
  • intermediate level of disturbance
• diversity increases productivity, resilience, and resistance
• life history: organisms schedule of reproduction and death
• elements of life history:

  • number of lifetime breeding episodes
  • fecundity: number of young per breeding attempt
  • age at first reproduction
• semelparity: one large breeding attempt, overwhelm predators
• iteroparity: multiple breeding attempts
• type 1 survivorship: greatest death at old age
• type 2 survivorship: constant death rate
• type 3 survivorship: greatest death rate at young age
• what are the two types of competition?

  interference and exploitation
• what do you call multiple breeding attempts?

  iteroparity
• what do you call one large breeding attempt?

  semelparity