Week 11 - Social Behaviour Flashcards
What are the three patterns of social organisation in animal societies?
- Stable Closed Social Groups
- Fission Fusion social groups WITH individual recognition
- Fission Fusion social groups WITHOUT individual recognition
Closed Groups: What are they? Can you give an example?
Individuals aren’t allowed to join - in a closed group there are FORCED evictions - typically by the alpha male and alpha female
Eg. Banded Mongooses
Fission Fusion Social Groups: What are they? Can you give an example?
Association is NOT random - there are structured interactions
- Group composition is HIGHLY DYNAMIC
- Anti-predator benefits (confusion, dilution etc.)
Eg. Shoaling Behaviours in the Trinidadian Guppy (fish hang out with fish of a similar size)
What are multilevel societies?
Core stable groups, but are dynamic all the way up to the population
Eg. Killer Whales - sons and daughters stay with mothers in a pod, but join with other pods to form superpods
What is the concept of the ‘Selfish Herd’
Individuals often behave in ways that increase their own fitness at costs to others - reduces the domain of danger
Do animals always behave selfishly? What promotes prosocial behaviour?
Animals do not always behave selfishly - some behaviours provide a benefit to others - the individual may pay potential costs for the individual
What is inclusive fitness?
An individual’s total fitness as based on both the NUMBER OF OFFSPRING IT PRODUCES and the REPRODUTIVE SUCCESS OF ITS RELATIVES
What is Hamilton’s Rule?
R * B > C
R - the genetic relatedness of the recipient to the actor
B - the additional reproductive benefit gained by the recipient of the altruistic act
C - the reproductive cost (eg. energy cost, time cost) to the individual of performing the act
Natural selection more strongly favours kin helping when RELATEDNESS IS HIGH, BENEFITS ARE HIGH, AND COST IS LOW
Example: Inclusive Fitness in the Pied Kingfisher
Primary Helpers - bring fish to their nestlings and attach threats
Secondary Helpers - help an unrelated nest
What is Kin Recognition? Kin Fidelity? Kin Choice?
Kin Selection requires kin to interact
Kin Fidelity - associations between kin based on spatial proximity
Kin Choice - discrimination between potential partners based on relatedness
Kin Recognition can have genetic and environmental components - individuals can use fidelity to recognise kins
How is the MAJOR HISOCOMPATIBILITY COMPLEX related to kin recognition and mate choice?
MHC - group of genes that code for proteins found on the surfaces of cells that help immune response
MHC genes influence odour
MHC has been theorised to play a critical role in:
MATE CHOICE - mating with close kin can result in reduced longevity, fewer offspring reaching maturity, and a weakened immune system
and SOCIAL PREFERENCES - group composition
What is the Green Beard Effect (an indirect genetic effect)
Suppose that a gene appears that has two effects: its owners have green beards, and help others with green beards…it is impossible to cheat the system - the gene would spread
