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**preview**shows half of the first page. to view the full**1 pages of the document.**Kin Selection Ch 6 205-207 Ch 12 447-453 467-477

Objectives

Categorize types of social interactions

Know when to apply the terms kin selection and

indirect fitness

Calculate relatedness and apply Hamilton’s Rule

Predict conditions favoring altruism among kin and

non-kin

Explain causes and outcomes of parent-offspring

conflict

Explain frequency dependent selection

The Evolution of Altruism

W.D Hamilton (1964): showed the conditions favoring

selection for an allele that causes altruistic behavior

Coefficient of relatedness, r:

Defined as the probability that homologous alleles in

two individuals are identical by descent

Note: this differs from F, the coefficient of

inbreeding, which is the probability that homologous

alleles in the same individual are identical by descent

Homologous – alleles identical by descent

Types of Social Interactions

In terms of fitness an interaction between individuals has 4

possible outcomes:

Cooperation (mutualism) - actions that result in fitness

gains for both participants

Altruism – individual instigating the action pays a fitness cost

and the individual receiving benefits (sacrifice on behalf of

another)

Selfishness – the actor gains and the recipient loses

Spite – behavior that results in fitness losses for both

participants (rare in nature, because it would be eliminated by

natural selection)

Calculating r with Pedigrees

1. Draw generalized pedigree of actor and recipient

2. Assign allele transfer probabilities

3. Calculate probability that homologous allele in actor &

recipient is identical due to descent from a common

ancestor

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