CHAPTER 50 INTRO TO ECOLOGY

1
CHAPTER 50INTRO TO ECOLOGY

• I. Ecology - study of the interactions between
  organisms and their environment
• A. abiotic (nonliving, chemical/physical)
  components of the environment
• B. biotic (living) components of the
  environment

2
II. Levels of Study in Ecology

• A. organismal ecology - study of behavioral,
  physiological, morphological ways in which
  individuals respond to a changing abiotic
  environment
• B. population ecology - study of a group of
  individuals of the same species living in the
  same area specific interest in factors
  affecting population size composition
  (including genetic composition)

3
Levels of Study (cont.)

• C. community ecology - study of all the species
  that inhabit a particular area specific
  interest in how predation, competition, and
  disease affect community structure
• D. ecosystem ecology - study of all the abiotic
  and biotic factors affecting the stability of a
  given area specific interest in energy
  flow/nutrient cycling

4
III. Abiotic Factors

• A. temperature
• B. water
• C. sunlight
• D. wind
• E. rocks and soil
• F. periodic disturbances

5
IV. Organismal Ecology

• A. Species exist where they do in part because
  of differential evolved capacities to maintain
  homeostasis under a given set of abiotic
  conditions.
• 1. regulation - use of behavioral
  physiological mechanisms to achieve
  homeostasis
• 2. conformation - allowing conditions within
  the body to vary with external changes

6
Organismal Ecology (cont.)

• B. guiding principles in determining why an
  organism is responding in a particular way to
  a given abiotic factor
• 1. principle of allocation - organisms have a
  limited amount of energy to allocate to various
  needs
• 2. optimality - organisms usually try to
  maximize benefit per expenditure
• 3. trade-offs constraints

7
Organismal Ecology (cont.)

• C. proximate vs. ultimate explanations
• 1. proximate - involves determining what is
  the stimulus, what is the response, what is the
  underlying internal mechanism
• 2. ultimate - involves an evolutionary
  understanding how is fitness maximized

8
Organismal Ecology (cont.)

• D. mechanisms for dealing with changes in
  abiotic factors
• 1. physiological response
• 2. morphological response
• 3. behavioral response