1. Kin Selection and Social Behavior

2. I. Motivation Cooperative behaviors are widespread. Why?

3. Genetically related female banded mongooses live and breed in groups, and care for each other's young

4. ActorRecipient +, -

5. An individual’s survivorship and reproduction relative to other individuals in the population (Direct Fitness) Hamilton’s Rule (1964): Inclusive fitness = Direct fitness + indirect fitness Kin selection: natural selection favoring the indirect component of fitness (B enefit x r elatedness) – C ost > 0 ; Br > C; r > C/B Benefit to recipient and cost to altruist Relatedness: probability that homolgous alleles in 2 individuals are identical by descent II. Theory of Altruism

6. Computing relatedness with pedigrees The arrows describe paths by which genes can be identical by descent Indirect Fitness through a Relative

7. Black-tailed prairie dogs give more alarm calls when kin are nearby III. Evidence

8. Male black-tailed prairie dogs change their alarm calling behavior when their living situation changes 5 males

9. Helping Behavior in Birds: White-fronted bee-eaters

10. In bee-eaters, helpers assist close relatives Fitness gains due to helping

11. Kin-selected discrimination in cannibalistic tadpoles and salamanders Benefit

12. IV. Special case of Sociality True or Eusociality = 1. overlap in generations between parents and offspring 2. cooperative brood care 3. specialized castes of nonreproductive individuals

13. Haplodiploidy produces unusual coefficients of relationship

14. Haplo-diploidy and Sister-Sister relationship mother father r = ½ ½ 1 1 sister Sisters on average share ½ genes through mother & all of their genes through father (1/2 + 1)/2 = ¾ Or ¼ + ½ = 3/4

15. phylogeny of the hymenoptera Origins of complex nesting behaviour

16. In paper wasps, the success of female coalitions varies

17. Naked mole-rats have highly inbred colonies

18. Naked mole-rat queens preferentially shove nonrelatives

20. Masked boobies Blue-footed boobies V. Siblicide and Parent-Offspring Conflict Older sib always pushes sib from nest Older sib sometimes pushes sib from nest

22. Vampire bats This photo shows a group of vampire bats roosting in a hollow tree VI. Reciprocal Altruism Cooperative behavior among non kin

23. Also fed nest mates that had fed them

24. Conclusion Cooperative behaviors are widespread Inclusive fitness (B x r) – C > 0 Haplo-diploidy Siblicide Reciprocal altruism (Tit for Tat) Other interesting topics: P-O conflict, sex ratio evolution, greenbeard alleles

25. Weaning conflict VII. Parent-offspring conflict

27. Parent-offspring conflict results from changes in the costs and benefits of parental care and asymmetries in relationship Full Sib half-sib Parent should stop investing below 1, and offspring will stop harrassing parent at ½, or ¼, respectively

28. Bee-eaters recruit helpers who are younger and closely related