Unit 2 Mating and Parenting Chapter 10

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

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

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

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

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

Courtship Displays One 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

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

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

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