Chapter 17

Question 1

Two types of sexual selection?

Answer 1

Intersexual and Intrasexual

Question 2

Intersexual selection?

Answer 2

Individuals of one sex select among individuals of the other sex as mates

choosier ones tend to be females

Question 3

Intrasexual selection

Answer 3

Members of one sex, most often males, compete with each other for mating access to the other sex

Question 4

Three types of mating systems?

Answer 4

• monogamous
• polygamous
• promiscuous

Question 5

Monogamous

Answer 5

Male and female mater with each other and only each other during a given breeding system (can be lifetime or seasonal)
think of humans

Question 6

Polygamous

Answer 6

Either males or females have more than one mate during a given breeding season or cycle

can be polygyny or polyandry

Question 7

Polygyny

Answer 7

Males mate with more than one female per breeding season

Question 8

Polyandry

Answer 8

Females mate with more than one male per breeding season

Question 9

Promiscuous

Answer 9

Both polyandry and polygyny, occurring at the same time

Question 10

Polygynandry

Answer 10

Several males form pair bonds with several females simultaneously

Question 11

What is the limiting resource for selective processes?

Answer 11

Eggs are limiting resource, so males should compete for access
&
Females should be choosier sex because eggs are expensive

Question 12

What is the difference between males being chosen by multiple or few to no females?

Answer 12

Multiple= high reproductive success

few or none= low reproductive success

Question 13

Amplexus

Answer 13

Pre-mating ritual in which males and females are joined together often with one individual on the back of the other

Question 14

Good genes

Answer 14

genes that code for some suite of favorable traits

Question 15

What are the two types of parasites & define them:

Answer 15

Ectoparasites: live on OUTSIDE of organism
Endoparasites: live on INSIDE of organism

Question 16

Hamilton-Zuk hypothesis

Answer 16

Body coloration is a good proxy of parasite overload. Healthy males tend to be colorful, while diseased males are duller.

Question 17

Runaway sexual selection

Answer 17

A gene that codes for a particular trait in males that over time becomes associated with a gene that codes for a particular behavioral mating preference in females.

(linkage disequilibrium arises between alleles for male phenotype and female preference)

Question 18

Sensory exploitation model

Answer 18

Females initially prefer a certain male trait but not because of any mating benefit that is associated with that male trait.

(female’s nervous system responds to trait because that’s how they’re “wired”).

Question 19

Sexual conflict

Answer 19

When differences in selection on males and females is great, traits that evolve in one sex may be detrimental to individuals in the other sex