post copulatory sexual selection- T.Birkhead, T.Pizzari Flashcards
what is a sexually antagonistic gene?
expression benefits one sex but is harmful to the other
what is cryptic female choice?
ability to bias fertilisation effect of males that copulate and inseminate
what can post copulatory sexual selection affect?
gene freq over generations
genetic diversity of pop
fate of additive genetic variation
what does the fact that the maternal genome in offspring mixing with genomes of many males result in?
rapid molecular evolution
high intersexual specialisation
pop divergence
what does a spread of sexually antagonistic genes result in?
sex limitation of expression
sex biased transmission control
what are 4 direct benefits of polyandry?
- nutrient acquisistion
- fertility benefits
- can obtain better partners
- reduced sexual harassment
3 indirect benefits of polyandry?
- offspring diversity
- offspring attractiveness
- offspring viability
what is anisogamy?
male and female gametes different sizes
in drosophila what do the phohormones, peptides, ACPs and enzymes released by males do?
act as anti aphrodisiac
deactivate sperm already in reproductive tract
what does Acp26Aa stimulate?
female ovulation
what can a high number of eggs do to male and female reproductive success?
can increase males
if beyond optimum can decreases females
what can coevolution between sexes result in?
rapid evolution of extreme traits
so pop divergence, reproductive isolation, speciation
what is intersexual coevolution?
evolution of sexual traits in one sex triggers a response in the other
what is a clade?
lineage of organisms/ alleles comprising an ancestor and all descendants
if sperm competition intensity high why may a male invest fewer sperm in ejaculate?
prob. of fertilisation reduced
do poly or mono insects produce more live sperm?
poly
how may lower status sheep in a flock be able to inseminate?
when later in the season and the dominant males become sperm depleted
what can promote fertilising efficiency?
seminal fluids
when is female choice at post insemination level favourable?
- when choice of partners costly
- when choice is based on phenotype and gene compatibility
what kind of males do females favour fertilisation from?
genetically similar
compatible genotypes
those with attractive alleles
what is the catalyst when pre and post insemination operate in unison?
sexual promiscuity
how can unattractive males compensate?
by having competitive ejaculates
what may post insemination selection be fundamental for?
for maintaining genetic polyphenism
what is it thought that promiscuous females sons will be like?
will be more able to fertilise
when will male efficiency traits not aid female fitness?
if inherited eternally
what can divergence in reproductive interests trigger?
can trigger rapid intersexual coevolution based on antagonism
what is mtDNA responsible for in males?
infertility
what is non directional cryptic female choice driven by?
genetic incompatibility
what is the -ve correlation between male and female fitness?
higher reproductive success of males= lower fitness of females
where is it predicted that the genes should accumulate?
on the sex linked regions of the genome
where do D.Melanogaster male fertility genes accumulate?
on Y chromosome
how can sperm efficiency be inherited?
through maternally transmitted mitochondrial genes
what may affect phenotypic variance of sexually selected traits?
environmental effects
what id the quantitative trait locus?
genetic locus identified by statistical analysis of complex traits
what 5 things do predictions of evolutionary response by post insemination sexual selection need info on:
- intensity of the selection
- selective mechanisms
- cooperation and conflict between male and female driven processes
- efficiency of post insemination mechanisms
- selection potential and mode of gene transmission
