lecture 6 - reproductive strategies Flashcards
types of interactions
intraspecific - within species
interspecific - among species
intraspecific interactions
group living
competition
reproduction
sexual conflict
interspecific interactions
predation and herbivory
competition
mutualism
parasitism and disease
pollination
what’s the purpose of reproduction
increase fitness
getting genes to the next generation
challenges with reproducing
choosing/ finding a mate
ensuring fetilisation
survival of offspring
how marine animals reproduce
external fertilisation
mass spawning
no mate choice
releases eggs and sperm into water
how mating by choice is limited
by how many offspring the female can carry
types of mating systems
monogamy -humans birds
polygyny - insects mammals ( 1 male many females )
polyandry - some birds and fish (1 female many males )
promiscuity - chimps
how mates are chosen
females choose in monogamy and polygyny = intersexual selection
males choose in polygyny = intrasexual selection
how is sexual selection a form of natural selection
traits selected for sexual selection are those that directly influence mating success
what is intersexual selection
selection for traits that increase attractiveness to females - colours
what is intrasexual selection
selection for traits that increase success in fighting - antlers
how did mate choice evolve
the good gene hypothesis- don’t use mating signals but instead show how good they are at acquiring food etc
the sexy son hypothesis - traits of mate will be passed onto their son increasing likelihood of mating in the future
how can sexual selection drive speciation
by choosing 1 type of mate for a long period of time
how is fertilisation ensured
intromittent organs
aedeagus in insects
hemipenes in squadmates
penises in mammals
