Chapter 11: Sex: Causes and Consequences

Question 1

reproduction

Answer 1

the formation of new individual offspring

Question 2

twofold cost of sex

Answer 2

asexual lineages multiply faster than sexual lineages because all progeny are capable of producing offspringin sexual lineages, half the resulting offspring are males who cannot themselves produce offspring → this effectively halves the rate of replication of sexual species

Question 3

Muller’s ratchet

Answer 3

the process by which the genomes of an asexual population accumulate deleterious mutations in an irreversible manner

Question 4

genetic load

Answer 4

the burden imposed by the accumulation of deleterious mutations

Question 5

Red Queen hypothesis

Answer 5

for coevolving populations, to maintain relative fitness, each population must constantly adapt to the other; term refers specifically to biological arms races such as those between hosts and parasites

Question 6

sexual selection

Answer 6

differential reproductive success resulting from the competition for fertilization, which can occur through competition among the same sex (intrasexual selection) or through attraction to the opposite sex (intersexual selection)differential reproductive success is due to variation among individuals in obtaining mates

Question 7

Maynard Smith’s assumptions

Answer 7

1. mode of reproduction does not affect number of offspring female can produce2. mode of reproduction does not affect probability offspring will survive

Question 8

sexual dimorphism

Answer 8

when males and females of a species differ physically in size and appearance

Question 9

sperm competition

Answer 9

a form of sexual selection that arises after mating, when males compete for fertilization of a female’s eggs

Question 10

parental investment

Answer 10

whoever has more parental investment (typically female) is choosier in determining mate → females must spend more time/energy on offspring