Cooperation II Flashcards
Three key approaches in social evolution
- Inclusive fitness approach
- Neighbour modulated fitness approach
- Multi level (group) selection approach
What is the theory of inclusive fitness?
An organism’s genetic success is believed to be derived from corporation and altruistic behaviour
Direct fitness
Measure of individuals direct reproductive success in passing on genes through offspring production
Indirect fitness
Genes contributed to the next generation by an individual via helping relatives (so indirect because help relatives which then produce offspring - the helper itself doesn’t produce offspring)
Inclusive fitness
The sum of an individuals direct fitness and indirect fitness
What’s an explanation for altruism?
Inclusive fitness - being altruistic and helping others is worth it if it means it can help pass on your own alleles (if u r the same species)
Altruism
Animals help other individuals increase their fitness at a cost to themselves
(Reducing my direct fitness to increase a relatives fitness)
What is Hamilton rule
An equality:
r B < C
r - relatedness
B - benefit to recipient
C - cost to the altruist
What does Hamilton rule tell us?
It tells us when altruism is expected to be selected for in a population
What does relatedness mean in Hamilton rule?
Proportion of alleles shared between altruist and recipient of altruistic behaviour
What does benefit to recipient mean in Hamilton equation
Number of offspring produced by recipient that wouldn’t have been able to be produced without help of altruist
What does cost mean in Hamilton equation
How many offspring the altruist is unable to produce as a result of altruistic behaviour
When does Kin selection occur
When an individuals inclusive fitness is increased by engaging in altruistic behaviour that enhances reproductive success of relatives
What is meant by relative?
Are they more genetically similar than average in the population
Definition of relatedness
Probability
Above average
That actor and recipient share alleles at a focal locus
How closely related are
Clones
Siblings
Half siblings
Non relatives
Clones 1
Siblings 0.5
Half siblings 0.25
Non relatives 0
What is kin selection THEORY
Anything that has a focus on relatedness
Neighbour modulated/inclusive fitness theory
What is kin selection PROCESS
Natural selection involving non zero relatedness
Involving individuals related above 0 - aka so must be clones/siblings/half siblings etc