Evolution of Sex

Question 1

Idea that genotypes are broken up each generation; each individiaul has a unique genotype

Answer 1

Sexual Recombination

Question 2

Costs of mating

Answer 2

ornamentation; pheromones; transportation; STD

Question 3

cost of recombination

Answer 3

breaking up successful genotypes; creating dangerous homozygosities

Question 4

cost of meiosis (cost of producing males)

Answer 4

pathenogensis: development of an embryo in the absence of fertilization

Question 5

benefits of recombination

Answer 5

• favorable mutant combinations occur faster
• deleterious mutatns eliminated faster

Question 6

Hypothesis that explains parasite-host co-evolution
- host evolve defenses, parasites evolve counter-defences, short life-spans + larger population = faster evolution

Answer 6

red queen hypothesis

Question 7

offspring have identical gene combinations

Answer 7

asexual reproduction

Question 8

offspring have unique gene combinations - more resistance to infection

Answer 8

sexual reproduction

Question 9

Why two sexes?

Answer 9

• intermediate gamete size: too large to produce in great quantity, to small to support embryogensis
• disruptive selection
• selection in sperm to pursue ova; less need for ova to become mobile

Question 10

Theory developed by Robert Trivers; the sex that makes the smaller obligatory investment competes for the sex that makes the larger investment; the sex that makes the larger obligatory investment will be choosier when selecting partners

Answer 10

parental investment theory