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ch 10 reproductive strats - Coggle Diagram
ch 10 reproductive strats
sexual or asexual
sexual=dna from two parents by union of two gametes
asexual=dna from single parent
vegetative=from tissues of parent(walking fern) clones or binary fission
parthenogenesis=producing embreo without feralization
costs of sexual reprod
considerable energy in production or corting
cost of miosis=50% loss of heratable genes
lost in hermaphodites and when both parents contribute
benefits of sexual repro
purging mutations
gard against enviromental change
defence against parasites and pathogens
red queen hypothesis=sexual reproduction pathogin resistance is faster than pathogens counter evoluation
sexual reprod organisms can evolve seperate sexes or hermaph
simultanious hermaphodite=make and female structures function at the same time
perfect flowe=both make and female parts in same flower
monoecious=male flowers and female flowers in samr plant
dioecious only male OR female flowers
sequential hermaphodite switches between sex use
comparing strats depends on overall fitness gained
selfing vs outcrossing pf hermaphodites
selection should favor indaviduals that do not use selfing but reach oth to others when possable (sequential hermaphodites (magnolia)
mixed strats
self fert or mix stick bugs
sex ratios of offspring are balanced but can be modifyed
mechanisms
genetic sex determination=inharatance of cromosomes xx or xy average 50/50 m&f or ants in the presence of cromosomes makes females and none makes males
enviromental
tempriture dertmines sex
living longer to grow from small female to large male
sex ratios commonlu determended by the female by choosing which cromosome fertalizes
selective abortion depending on energy expendature more cost for males
frequency dependent selction=rarer phenotype in a pop is selected by natural selcest (fishing salmon)
highly skewed ratios fig wasps 90%female males only used for reproduction
can cause local mate competition or when compatition for mates takes place in a limited area and only a few males are needed
mating systems describe pattern of mating between m&f
mating systems=number of mates and indvid has and the performance of the relationships
promiscuity=indavids mate with multable partners and no social bond (most common) plants
poligamy= single indavid of one sex forms long term social bond and mates with more than one of the opposite sex.
polygyny male and more than 1 female humans
polyandry female and more than one male bees(superior sperm)
monogomy=one male and one female through the period of reering sometimes till one dies and sometimes may not take another mate (males contribute)
extra pair copulation=female with one male but breeds with other males(birds) greater repod sucess
mate garding =one partner prevents the other partner from participating in extra pair copulations many times preventing others from breeding the female
sexual selection favors traits that favilitate reproduction
sexual selection = natural selection fot sex specific traits related to reproduction
sexual dimorphism=phenotype difference in sexes of same species
primary sexual characteristics=traits related to fertalization
secondary sexual characteristics=size, color, courtship
contest between males(bigger males) or female choice(bigger female)
honest signals=traits that are accurate respresentations of an animals performance
evolution of female choice
female preference of male traits are tied to features that would approve her fitness
material benefits=physical items males can provide,site for raising offspring,good terratory or abundent food.
non material benefits such as being pretty
good genes hypothesis=prettyor non material action=superior genotype
runaway slection=when selection for prefernce of sexual trait and selection for that trait continue to reinforce eachother(continue unitll males run out of variation or untill firness is costed by extreme trait
handicap principal=greater the handicap an indavidual carries the greater the ability to offset it
parasites and pathogens effect male shoeyniss