Sexual Selection Flashcards
What is parthenogenesis?
Only female species.
What is the Bateman principle?
Females tend to limit male reproductive success.
What is the result of the bateman principle? Why?
More variability in male reproductive success than in female reproductive success due to male-male competition.
What is intersexual selection?
Selection for traits in one sex that attracts the other sex.
Is sexual selection greater in monogamous or polygamous species?
Polygamous species.
What is intrasexual selection?
Selection for the ability of one sex, often males, to compete with each other for access to the other sex, often females.
What are the two main categories of intrasexual selection behaviors?
Precopulation and postcopulation.
What are four examples of precopulation intrasexual selection?
- Aggression. 2. Dominance. 3. Interference. 4. Cuckoldry
What is an example of postcopulation intrasexual selection?
Sperm competition.
What are two types of alternative mating strategies?
- Conditional strategies. 2. Heritable strategies.
What is a conditional alternative mating strategy?
An inherited mechanism that gives an individual the ability to alter its behavior adaptively based on the conditions it encounters.
What is a heritable alternative mating strategy?
Variation in morphology and/or behavior is shaped by genetic differences.
What two types of strategies can a male adapt for postcopulatory sexual selection?
- Reduce the chances that a second male’s sperm is used (first male). 2. Reduce the chances that the first male’s sperm is used (second male adaptations).
What are three examples of a first male’s postcopulatory adaptation?
- Mate guarding. 2. Anti-aphrodisiacs. 3. Mating plugs.
What kind of adaptation is infanticide?
Indirect interference.
What is the bruce effect?
Spontaneous abortions when a new male is encountered.
What are three reasons why females would be choosy?
- Resources. 2. Parental care. 3. Genetic benefits.
What is the healthy mate hypothesis?
Females choose traits that show a healthy male in order to avoid contagions or parasites.
What is the MHC gene?
Gene associated with immune system variability.
What is the Runaway selection hypothesis?
“Sexy son hypothesis” Inherit traits that made them sexually attractive.
What is the Chase-away selection hypothesis?
Exploitative of pre-existing sensory biases - females derive no benefits by being choosy.
What is symmetry theory? What might it indicate?
Many organisms prefer the most symmetrical mates. Might indicate co-adapted gene complexes that work well together during development.
Those with fluctuating asymmetry show what?
Lack of genetic immunity from diseases during development.
When is sex role reversal more common (2)?
- In monogamous species. 2. Species where the male invests more in offspring.
What is plasticity in female choice?
Females are less choosy when predators are around.
