Transcript Parent-Offspring Conflict

Evolution of the Family
Evolution by Kin Selection
Genetic Trait Expressed in Actor (Ego)
Must Affect Genotypic Fitness of
Individual Related to Actor at Locus
Determining Trait
Altruism, Selfishness, Mutualism
Evolution of the Family
Evolution by Kin Selection
Kin-Based Altruism
Helpers at the Nest (Diploids)
Sterile Worker Caste, Eusociality (Haplo-Diploids)
Evolution of the Family
Proximity of Relatives
Competition Among Kin
Dominant, Subordinate Offspring
Siblicide, Fratricide
Brood Reduction (By Offspring Sex)
“Weaning” Conflict
Gauthier & Barrette. 1985. Behaviour 94:128.
Gauthier & Barrette. 1985. Behaviour 94:128.
Feeding of Fawns in 2 Deer Spp
As Fawns Age
Fewer Bouts
Decreasing Proportion Initiated by Mother
More Frequent Rejection by Mother
Fawn Independence Increases;
Mother Future Reproduction
Packard et al. 1992. Canadian J. Zool. 70:1269.
Arctic Wolves
Dominant Female
Suckling Less
Frequent & Bouts
End Sooner as
Cubs Age
Packard et al. 1992. Canadian J. Zool. 70:1269.
Packard et al. 1992. Canadian J. Zool. 70:1269.
Feeding of Cubs in Arctic Wolf
Standard Pattern in
Frequency, Initiation & Termination
As Offspring Age
Predict Why Close Kin “Fight?”
Parenting
Parental Care Per Se
Traditional Darwinian Explanation
Adequate, But Can Justify via
Hamilton’s Rule
Parent-Offspring Conflict:
Parent Gives Care to Offspring
Offspring Demands Parental Resource
Parent-Offspring Conflict
Parent-Offspring Conflict (Diploidy)
Parent Altruism
Offspring Selfishness
Close Relatives: Hamilton’s Rule (General)
Parent-Offspring Conflict
If Parent Allocates Resources to Offspring:
B Benefit to Offspring
C Cost to Parent, Loss of Future
Reproductive Success
r (Parent to Offspring) = 1/2
Kin Selection
Parent Allocate Resources to Offspring?
Hamilton’s Rule:
Increase Parent’s Inclusive Fitness
r B – C > 0, Implying
C/B < (1/2) Parental Altruism Favored
Kin Selection
Offspring Demand Parental Resources?
Hamilton’s Rule Generalized:
Increase Offspring Inclusive Fitness
ES Effect on Self = B
ER Effect on Relative (Parent) = - C
r (Offspring to Parent) = 1/2
Kin Selection
Offspring Demand Parental Resources?
Increase Offspring Inclusive Fitness
ES + r ER > 0
B – (1/2) C > 0;
C/B < 2 Offspring Selfishness Favored
Kin Selection
C/B < ½ Parental Altruism Favored
C/B < 2 Offspring Selfishness Favored
½ < C/B < 2
Parent Should Not Be Altruistic
Offspring Should Be Selfish
Kin Conflict
Kin Selection
Selfish Genes Can Lead, Evolutionarily,
To Cooperation and Altruism
Gene Spreads by Helping Other
Individuals Carry Same Gene
Hamilton’s Rule;
Hamilton’s Conjecture
Kin Selection
Limited Dispersal (of Newborns) Makes
Neighbors Close Relatives
Enough Local Relatedness Might Lead to
Cooperation/Altruism Toward
Any Neighbor
Kin Selection
Viscous Population, Low Dispersal,
Relatives = Neighbors
Limited Dispersal Also Can Make
Relatives Close Competitors
Competitive Local Conflict Over
Resources Negate Effect of Kin?
Limited Dispersal and Kin
Evolution of Cooperation
Relatedness Promotes (Hamilton)
Local Competition Impedes
Interaction
Local & Global Scales
Behavioral Interactions
Local, Ephemeral
Drive Ecological, Evolutionary Dynamics
Ecology, Evolution
Global (Population), Extended Timescale