Lecture 14 Flashcards
What are conspicuous ornaments
Differences between male and female appearances such that males have elaborate patterns while females typically look the same
What are conspicuous behaviours
Males performing dances/trying to make themselves look larger to attract females
Define armament
Weapons on an animal used for competition (ex. Antlers)
What is a trade off? Explain using a peacock as an example
A condition that has both advantages and disadvantages (ex. peacock plumage attracts mates but also predators)
Define ansiogamy
Describe the characteristics of the egg and sperm
The inequality in gamete size
Egg: large, few, resource rich
Sperm: small, many, inexpensive
What is the Parental Investment Theory (Robert Trivers)? (3)
Sexes differ in their reproductive investment
Every offspring has a mother and father
Members of the sex that invests little must compete among themselves to mate w the members of the sex that invests more in the offspring
What are the two methods of sexual selection?
Intrasexual selection: competition amongst males (male-male) for a mate
Intersexual selection: selection bw males and females where females choose a mate among the males
What limits males and females in reproductive success?
Males: access to fertilisable gametes
Females: access to resources (how many eggs they can make to hold offspring)
What are the axes of the Bateman Curve? What do their respective male and female trend lines display?
Independent: number of mates
Dependent: total number of offspring
Male trend: giving males more access to females increases their reproductive rate
Female trend: giving female one male is enough to fertilize all her offspring
Forms of intrasexual selection (2)
Pre-copulatives (# of copulations): fighting behaviour, territoriality, social status
Post-copulatives (success of copulations): sperm competition
Relationship bw social status and mating success
Walruses determine a dominance hierarchy as dominant males get more compilations
Relationship bw territoriality and mating success
Elephant seals fight to get access to/defend their territories as females choose the best beach to lay eggs
Sperm competition (
Male guarding Sleep removal Copulation duration Sperm plugs Traumatic insemination Anti-aphrodisiacs
As an alternative reproductive patten comes the arrival of new forms
Bluegill sunfish: parental male, satellite male, sneaker male
As an alternative reproductive strategy the side-blotched lizard shows that selection was what?
Frequency dependent
