Sexual Selection Flashcards
Differential Reproduction
Critical to natural selection
Sexual Selection
selection arising from differences in mating success
Selection arising from competition between or within sexes in a single population
Adaptations
Features which enhance relative fitness and thus lead to greater reproductive success
Materials For Selection
Differences in phenotype that have consequences for survival and reproductive success
Copulation (reproductive model)
Individuals recognize and encounter conspecifics of the appropriate sex
Means of transmitting gametes
requires time and energy searching for mates
number of potential encounters may be limited so each copulation potentially limits future choices or opportunities
Spawning (reproductive model)
Coordination of members of population with respect to timing of spawning
typically prevents extensive parental care
concentration and density of gametes appropriate to environment
gamete recognition mechanisms
Polyandry
oldest and largest individual is a female, males compete for access
- better guarantee of successful reproduction
- promote competition among males and among their sperm –> more variation possible
- multiple males can procure more resources for the female
Polygyny
Oldest and largest individual is a male, maintains group of females
males maximize mating opportunities
intrasexual
sexual selection between members of one sex for access or opportunity
intersexual
preference by one sec for certain phenotypes in mates
what is assortative mating? what two types are there?
contrast to random mating
positive assortative mating and negative assortative mating
Positive assortative mating
preference for similar phenotype (possible inbreeding)
Negative assortative breeding
preference for different phenotype
may make it hard to maintain species boundaries
what are the components of reproductive fitness?
Viability Mating Success Fecundity segregation advantage gamete viability fertilization success
Who typically picks for mating
Females