Lecture 15

Question 1

Sexual Selection

Answer 1

differential reproductive success due to variation among individuals in success at getting mates

Question 2

Sexual selection introduces what as a third problem?

Answer 2

1. Survival
2. Reproduction
3. Securing a mate

Question 3

Reproductive Investment

Answer 3

Investment in gametes varies between sexes

One sex, usually the female, invests more than the other

Question 4

Bateman’s Principle

Answer 4

1. The sex with the greatest parental investment should be choosy (quality)
2. The sex with the least parental investment should be as promiscuous as possible and compete for mates (quantity)

Question 5

Difference on limitations for reproductive success

Answer 5

Females are limited by fecundity

Males are limited by number of mates they can obtain

Question 6

Behavioral Consequences of Asymmetric Parental Investement

Answer 6

Males should be competitive
Females should be choosy
Due to parental investment

Question 7

Operational Sex Ratio

Answer 7

Sexually competitive males that are ready to mate : sexually competitive females that are ready to mate.

Question 8

Intrasexual Selection

Answer 8

Male to male competition

Question 9

Armaments

Answer 9

weaponry used to out-compete other individuals

Question 10

Sperm Competition

Answer 10

Copulatory plugs
Sperm removal device
Large testicles
Sperm heteromorphism

Question 11

Intersexual Selection

Answer 11

Female Choice

Question 12

Ornaments

Answer 12

attractive traits that increase mating success

Question 13

Direct Benefits of Female Choice

Answer 13

Protection
Territories/nests
Food
Help Raising Young
Reduced risk

Question 14

Honest Signals

Answer 14

Costly ornaments can signal good genes

Question 15

Alternative Mating Strategies

Answer 15

Parentals (court females, defend nests, delay maturity)
Large Sneakers (mimic females, matures at intermediate age)
Small Satellite Sneakers (dart in and spray sperm, mature early)