Please enable JavaScript.
Coggle requires JavaScript to display documents.
Kin Selection Theory & Kin Altrusim - Coggle Diagram
Kin Selection Theory
& Kin Altrusim
Defining altruism
Psychological def - unrewarded prosocial behaviour
Biological def - measured with expected Darwinian fitness (RS)
Mutualism, Altruism, Selfishness, Spite
Eusociality
Insects, BGS
Kin Selection Theory
Hamilton
Restraint of aggression
Relatedness
Wright's coefficient of relatedness (
r
)
Degree of genealogical closeness
Probability that two individuals share a gene
by descent
MZ twins -
r
= 1
Note: not a measure of shared genes
How does KS work?
A gene contributing to tendencies for aiding others can positively impact its population frequency
if
the recipients of the aid are more likely than chance to possess the same gene
Unconditional altruism --> all alleles receive aid --> no change to pop freq
Targeted altruism --> same alleles receive aid --> increase in pop freq
Genetic relatives more likely to share gene
Probability of sharing genes by descent
Population frequency of gene
Hamilton's rule
br>c
b
- benefit to recipient - avg number of additional offspring
c
- avg number of additional offspring if the actor had the non-altruistic variant
Inclusive fitness =
direct fitness + indirect fitness
Genes contributing to KA tendencies are selected - enhance own fitness through effects on bearer's kin
Not about spreading all genes; just the genes that promote KA tendencies
NS VS KS
Examples - ants, BGS, birds
Parental care
TCE
Adoption
Eliciting parental responses
Genetic conflict / parent-offspring conflict - Trivers (1974)
r-/k-selected species
Extended family
Experimental data
Archival data
Friendship
Culture
Kin recognition
Early-life cohabitation
Phenotype matching
Psychological mechanisms
Helping romantic partners VS kin
Other variables impacting KA
Relatedness certainty
Mating opportunity cost
Reproductive value
Health
Incest avoidance
Inbreeding depression
IA mechanisms
Dispersal
Westermarck effect
Facial resemblance
Implications of KST
Psychological disorders
Prejudice and discrimination