3/2/2017 lecture: problem with sex II Flashcards Preview

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Flashcards in 3/2/2017 lecture: problem with sex II Deck (20):

conjugation in bacteria

genetic material is transfered from donor cell to reciepeint cell - tube grows donated DNA replaces same loci on chromosome of reciepient cell


problems in discussing evolution of sex

ecological problems, physiological problems


genetic represnetaiton in future generations



cost of producing males/son

sons absolutely worhtess except to produce sperm


cost of meiosis

cost only for sexually reproducing organisms - offspring produce sexually reproduce 2x genetic representation of sexually producing offspring; 2x payoff when reproucing asexually


mating promiscuity vdifference in white blood count

more sexual partners, more white blood cells in blood- you pick up more parasites


additional costs of sex

physiological costs, ecological costs


adaptive reasons for sexual reprodcution

asexual population - acceleretied rate of evolution, muller's ratchet, dna repair, repsonse to environemntal heterogeneity


asexual population - accelerated rate of evolution

asexual populations grow faster - fitter- as copared to sexual population - evolve slower bc it takes whole lineage in idnividual - accelerated rate of evolution


what is the issue with asexual population

group selection- altruistic traits evolve through group selection for "good of speiiceS" results in reproductive restraint and aid- giving behavior - adpatations/traits don't arise for purpose to help organisms - bad for population, good for individuals - VC Wynne Edwards; grow faster, adapt slower


muller's ratchet

mutations constatly arise can only go in one direction - mutation in one unlikely to occur in other- removal of deleterious mutations from pop - removal of deleterious mutations from pop.


muller's ratchet - the problem with this

mutational load doesn't go fast enough, not the entire answer


dna repair

repair mechanisms - like crossing over (in recombination), fix DNA, put back together, glue back, dna repair is important - otehrwise you die


problem with DNA repair

doesn't explain everything by self


response to environemtnal heterogeneity

environment changes in time , environemnt changes in space


environemnt changes in time is

temporal, environemnt changes


environemtn change in space is

spatial - dif environemtn, leave diff environemnt


rotifer example

homogeneous v heterogeonous environment
homogeonous- asexual
heterogeounous - sexually


tangled bank hypothesis

spatial heterogeneity like lottery, problem - not lot of evidence - only rotifier proves
ie - snails infect with trematodes


red queen hypothesis

benefit of sex is to recombat parasites and produce genetic diversity

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