Lecture: Behavioral Ecology
Updated: 9 February, 2009
- Cooperate in the caring of brood.
- Division of labor.
- Overlap between generations.
Discrimination in graduate school admissions -- University of xxxxxxxxx
The law -- The U.S. Equal Employment Opportunity Commission
The data --
|SEX OF APPLICANT|
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?
- 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 act||Self||Other|
Hamilton's rule is in terms of absolute RS not relative terms of fitness.