6d. Sexual Selection: human mating strategies

Question 1

What are the negative aspects of sexual reproduction from an evolutionary viewpoint?

Answer 1

It is costly and transfers only 50% of DNA to offspring

Question 2

Why bother with sexual reproduction?

Answer 2

The advantage of sex is increased VARIATION due to genetic recombination and mutation (asexual species don’t have this)

Question 3

TRUE OR FALSE: Asexual species are more able to adapt and more complex.

Answer 3

False: Asexual species are LESS able to adapt and LESS complex.

Question 4

Example of an asexual species and how it reproduces

Answer 4

Bacteria - a single cell splits into 2 daughter cells

Question 5

TRUE OR FALSE: Most species reproduce asexually.

Answer 5

False: Most species reproduce sexually

Question 6

How many mammal species are there?

Answer 6

4,300

Question 7

How do most mammals’ sexual activity differ from humans?

Answer 7

Most mammals do NOT pair-bond or have nuclear families
Most often meet only to copulate
In most mammal species, females mate only in oestrus (sex is NOT recreational)

Question 8

TRUE OR FALSE: Many animals only meet to mate and provide no paternal investment.

Answer 8

True

Question 9

Harem mating systems

Answer 9

Dominant males (high testosterone) have bigger harems (and more offspring)
Females are attracted to males with large territories

Question 10

In what percentage of mammals does obligate monogamy (‘marriage’) occur? And what species is it common in?

Answer 10

5% of mammals

Common in birds

Question 11

Why do humans have recreational sex?

Answer 11

May cement long-term pair bonds necessary for raising children
Concealed ovulation means a man does not know when his partner is not fertile

Question 12

TRUE OR FALSE: Mating strategies vary between AND within species.

Answer 12

True

Question 13

What is the difference between a ‘cad’ and a ‘dad’?

Answer 13

Cads have a large number of short term mating opportunities

Question 14

Are women monogamous? Research

Answer 14

50% of married men had extra-marital sex (an affair)

26% of marries women has extra-marital sex by their forties

Question 15

Little Kinsey

Answer 15

Britain, 1949
First UK nationwide sex survey
1/4 men admitted sex with a prositute
1/5 women admitted extra-marital sex
Findings considered so outrageous they were suppressed

Question 16

Polygamy has led to the evolution of…

Answer 16

jealousy (‘mate guarding’)

Question 17

TRUE OR FALSE: Men and women experience equal amounts of jealousy.

Answer 17

True

Question 18

What is different about the form jealousy takes in men and women?

Answer 18

Male jealousy - primed by their partner’s real/imagined SEXUAL infidelity
Female jealousy - primed by their partner’s real/imagined EMOTIONAL infidelity

Question 19

Sex differences in jealousy - research

Answer 19

Ps imagined (a) their partner having sex with someone else, or (b) their partner becoming emotionally involved with someone else
Men more distressed by sexual infidelity
Women more distressed by emotional infidelity

Question 20

Reason for sex differences in jealousy

Answer 20

Men - cuckoldry

Women - resources, parental investment

Question 21

Major problem with research into infidelity and jealousy

Answer 21

Much research is based on IMAGINED infidelity

Question 22

Jealousy triggers strategies of…

Answer 22

mate retention

Question 23

Emotions and cognitions associated with jealousy

Answer 23

Fear
Anger
Sexual arousal / passion

Question 24

Mate retention tactics include…

Answer 24

emotional manipulation
submission
physical signs of possession
threatening/attacking competitors
violence to partner
love and care

Question 25

TRUE OR FALSE: Fitness advantages of marriages are equally as obvious for men as for women.

Answer 25

False: Less obvious for men given high fitness variance

Question 26

Why do many men commit to one woman, instead of trying to increase quantity of offspring?

Answer 26

> Big brained human babies require lots of parental care
Provides exclusive sexual access to one woman
Reproductive success depends more on mating with many women… e.g. children with paternal investment likely to fare better

Question 27

Monogamy is common in _____ cultures

Answer 27

western

Question 28

What is serial monogamy?

Answer 28

Having a series of monogamous relationships

Question 29

What is polygyny?

Answer 29

1 male, more than 1 female

Question 30

Monogamy increases the likelihood of…

Answer 30

lower quality males finding mates, but compromises female choice

Question 31

Polygyny is not all bad for females

Answer 31

It may be more ‘suitable’ to be the 2nd wife of a successful male than the 1st to a poor one

Question 32

What is polyandry?

Answer 32

1 female, more than 1 male

Question 33

Why is polyandry much rarer than polygyny?

Answer 33

Tends to be in response to harsh environmental conditions

Question 34

Why is polygamy the most suitable mating strategy for parental investment, theoretically?

Answer 34

Males seek high QUANTITY of partners, females seek high QUALITY of partners

Question 35

TRUE OR FALSE: Monogamous species have less sexual dimorphism and difference among males.

Answer 35

True

Question 36

Humans approximately __% sexual dimorphism, compared with >__% in gorillas

Answer 36

15%

> 50%

Question 37

TRUE OR FALSE: Neither sex is entirely naturally monogamous.

Answer 37

True