General Ecology, ECOL 3500, University of Georgia

Lecture: Behavioral Ecology

Updated: 9 February, 2009


  • Eusociality
    1. Cooperate in the caring of brood.
    2. Division of labor.
    3. Overlap between generations.

    Paper wasps

  • Discrimination in graduate school admissions -- University of xxxxxxxxx

    The law -- The U.S. Equal Employment Opportunity Commission

    The data --


    Analysis -- Online calculator

    Based on these data, did the individuals who made the admissions decisions necessarily discriminate on the basis of sex?

  • Units of Selection
    • Gene -- "Selfish Gene" by Richard Dawkins
    • Chromosome -- Meiotic drive / Segregation distortion
      e. g., t-allele in mice: XY males only produce Y gametes, male offspring
    • Individual -- classical Darwinian selection
    • Kin selection -- Inclusive Fitness Theory, Wm. D. Hamilton, 1964
      Inclusive Fitness = Personal fitness (Darwinian) + Kin component
    • Interdemic Selection
      e. g., counters t-allele through reduced productivity of small male-biased populations
    • Group Selection -- Wynne Edwards
      Are non-reproductive individuals not reproducing for the good of the species?
      "The Group Selection Fallacy" [Trivers, Chapter 4]
      David Lack's work on the number of surviving offsping (fledging) versus the number of eggs per nest. Albatross experiment: 1 (control) versus 2 (experiment) eggs.
    • Higher Levels?

  • Definitions
    • Reproductive Success (RS) -- measured in terms of the number of surviving offspring (grandchildren, ...)
    • Hamilton's rule used to explain social behavior.
    • B r > C
      B=benefit to other infividual
      C=cost to actor
      both B and C measured in terms of reproductive success
    • r -- relatedness
      Degree of relatedness or coefficient of relatedness
      Can be defined as:
      "Given a gene at random from individual-A, what is the probability that the same gene, identical by decent, is in individual-B"
      This is B's relatedness to A.
      Not necessarily A's relatedness to B, but is generally the case for diploid organisms that are not inbred.
    • Diploid: Son, daughter, mouther cousin, 1/2 sibling,... Symmetrical
    • Haplodiploid: sometimes not symmetrical.
    • Using Hamilton's rule can check whether type of acts are favored.

      Type of actSelfOther

    • Hamilton's rule is in terms of absolute RS not relative terms of fitness.

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