Unit 2 Mating and Parenting

1. Unit 2 Mating and Parenting Chapter 10

2. Sexual Conflict • Each parent has a diff investment in young • Males do fertilizing, as many as possible • Females raise young • Both want to max their reprod success • Genders behave diff

3. Sexual Selection • Used to max reprod potential • Sexual dimorphism- genders look and behave differently • Ex: elephant seals, primates, fish, hyenas, crayfish • It is more important to have reproduct. success than survival skills

4. Intrasexual Selection • Members of one sex compete for mate • Males compete w/each other for females • Hoarding, guarding, repelling • Being sneaky • Sperm competition- remove old sperm 1st

5. Intersexual Selection • Females choose which male they want • Males compete for female attention • Use sounds and displays • Ex: peacocks, bats, fish, kakapo, birds of paradise

6. Courtship RitualsBoth genders interact • Functions: • 1. Identification • 2. Reduction of aggression • 3. Fitness assessment • 4. Mating readiness assessment • 5. Bonding

7. Courtship DisplaysOne sex does this • Theories: • 1. Runaway evolution theory- originally the feature showed fitness, over generations it became more pronounced • 2. Good genes theory- those w/ handicap survive despite it, indicating fitness

8. Lek displays • Place where males congregate to attract females • Chorus- when males call for females

9. Alternative Reproductive Strategies • Hermaphrodites possess both male and female sex organs • Slow movers • Solitary lifestyles • Ex: worms, mollusks, certain fish, etc.

10. Sex change as reprod strategy • Protogynous hermaphrodites- starts off as a female and changes into male • Protandrous hermaphrodites- starts off as a male and changes into female