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Announcements

Announcements. Parental care Very costly behavior - time - energy - vulnerable to predation. emperor penguin. red shouldered hawk. earwig. tarantula hawk. Sibling conflict Sibling aggression and siblicide Occurs when resources are variable or in short supply?

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Announcements

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  1. Announcements

  2. Parental care Very costly behavior - time - energy - vulnerable to predation emperor penguin red shouldered hawk earwig tarantula hawk

  3. Sibling conflict Sibling aggression and siblicide Occurs when resources are variable or in short supply? Offspring compete for resources (they only share 50% of genes)

  4. Galapagos blue-footed booby have two eggs, often raise two young masked booby have two eggs, first hatched chick always kills second chick

  5. Parent offspring conflict (Trivers) Selection may act on parents and offspring differently. Some actions that increase fitness of offspring may reduce fitness of parents.

  6. Parental favoritism Likely occurs when resources are variable and adults have more young than they can raise (bet hedging) Females can invest in eggs differently (even choose sex in some species). Young can be fed preferentially. Seychelles warbler

  7. Parental favoritism Honest signals of quality in offspring? barn swallows

  8. Asynchrony in hatching (birth order) can promote or reduce sibling conflict and parental favoritism great egret

  9. Can parents control sex of offspring? Seychelles Warbler

  10. Can parents control sex of offspring? Haplo / diploid organisms (like ants, bees and wasps) fertilized egg = female ; un-fertilized egg = male Temperature Dependant Sex Determination (TSD) many reptiles

  11. Helpers at the nest In some animals, juveniles stay to help second nesting effort. More often female juveniles. Both direct and indirect benefits. Direct (learning about maternal care) Indirect (inclusive fitness by helping rear related offspring magpie jays voles

  12. Helpers at the nest Leads to overlapping generations Key step in the evolution of sociality?

  13. Genetics basis for mating systems / parental care. prairie voles Monogamous, male parental care meadow voles polygynous, no male parental care

  14. In male prairie voles, vasopressin and dopamine in the forebrain regulate affiliation between mates (bond formation). Vasopressin receptor is expressed at higher levels in monogamous species than polygynous species. Lim and colleagues, used a viral vector to transfer the vasopressin receptor gene from the monogamous species into the polygynous species. With this change in a single gene, the polygynous species essentially became monogamous.

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