expenditure on present offspring that increases that offsprings chance of survival at the expense of future offspring.
favors traits that affect the ability of members of the same sex to compete with each other for mates
(lots of competition) strong relationship to physical attributes and the number of matings they have. Defend mating sites, defend mates, ability to avoid damage
"bruce effect" pregnancy disruption in which exposure of female to a new male results in abortion
when female is with young she is not able to mate, so males will come and kill her young so she can mate.
rejection of members of wrong species, selection of partners with resources, selection of partners with good genes.
resources given to increase length of mating or decrease probability of female mating again
secondary sexual characteristics
physical or behavioral characteristic that appear in sexually mature animals, differentiate between the sexes without having direct reproductive function
fischer's runaway hypothesis
1. trait starts by conferring some advantage
2. preference for trait that confers advantage evolves
3. eventually the offspring of these matings with have genes for traint and genes for prefeering trait
4. leads to a runaway process- prefenece is given even though the exagerated trait no longer confers a fitness
signals are costly so they information conveyed is honest and shows males genetic quality (peacocks)