set 3

Question 1

sexual selection

Answer 1

• the natural selection of preference by one sex for certain characteristics in individuals of the other sex that allow you top reproduce
• most research focuses on things what get you noticed by a potential mate or how to keep a potential mate
• never-one-directional it is mutual

Question 2

ancestral dimorphism

Answer 2

• fossil record of other hominid species
• can look at sexual dimorphism in their physicality because it is difficult to find evidence of their behavioural dimorphisms
• in a variety of early hominid species there is much larger sexual dimorphism in the skeletons compared to modern day humans
• e.g. males used to have much more pronounced brow and chin/jaw bones
• many skulls are no longer identifiable as male or female just by looking at them

Question 3

modern dimorphism

Answer 3

• humans have minimal sexual dimorphism (physically and behaviourally) depending on what trait you are looking at (15% dimorphism)
• the largest differences tend to be reproductively relevant
• e.g. the reproductive process, attracting a mate, intersex and intrasex competition and signalling reproductive readiness

Question 4

reproductive speed

Answer 4

refers to how quickly can you go from one conception to the next

Question 5

reproductive speed in females

Answer 5

• slower reproductive speed than males (reproductive windows ranging from 2-5 years)
• in a modern environment women can get pregnant almost immediately after giving birth, given they have enough fat stores, making it a 10 month window between offspring

Question 6

reproductive speed of men

Answer 6

can be minutes and even hours theoretically

Question 7

reproductive potential

Answer 7

the inherent biological ability of an individual or species to reproduce

Question 8

reproductive potential of males

Answer 8

• a male’s reproductive potential is almost unlimited
• male fertility and sperm quality declines with age, but it is still potentially possible to impregnate someone
• they just need enough fertile mates making female choice, availability and willingness the limitation on male reproductive success

Question 9

reproductive potential of women

Answer 9

• a woman’s reproductive potential in limited and lower because it is impacted by age
• often peaking in the late teens to late 20s and declining after age 30, with a significant drop by the mid-30s and minimal natural fertility after 45

Question 10

reproductive opportunities and males

Answer 10

• it is a selective pressure for males to compete and want to capitalize on reproductive opportunities
• females are virtually guaranteed to reproduce in a healthy environment but the same is not for males because there is so much competition surrounding access to fertile females

Question 11

concealed ovulation

Answer 11

• just by looking at someone with ovaries you don’t know whether they are currently fertile or not
• females have cycling fertility
• women can get pregnant at any point in the cycle but are more likely at certain parts
• on average females don’t know about it either

Question 12

concealed conception

Answer 12

ability to sleep with multiple partners, where which led to the conception can be entirely unknown to both parties

Question 13

mate guarding

Answer 13

behaviours, practiced by males or females, that aim to maintain reproductive opportunities by preventing a current mate from defecting from the relationship and by warding off rivals

Question 14

intersex competition

Answer 14

competition between sexes

Question 15

intrasex competition

Answer 15

• competition within a sex
• related to being able to access viable mates and keep viable mates
• may be an aspect of stabilizing selection in that the largest or most aggressive is not always the one that gets selected but the ones that have enough size, strength and potentially some tendency toward aggression

Question 16

cues about fertility

Answer 16

• both sexes are interested in cues of fertility but males are more focussed then females
• the human body is sexually selected to displaying cues associating with fertility
• e.g. secondary sex characteristics: height, broad shoulders and jaw, wider hips/pelvis,

Question 17

hip to waist ratio - cues about fertility

Answer 17

• the waist to hip ratio is typically 0.6-0.8 in healthy females and is the ratio associated with fertility and higher male preferences
• in males the preferred ratio is 0.85-0.95 and is related to the greatest likelihood this person can impregnate another as well as female preference

Question 18

endocrine status in sexual selection

Answer 18

production of androgens, estrogen, testosterone, etc

Question 19

perceptual pressure to notice cues - sexual selection

Answer 19

being able to notice an attractive trait in someone is just as selected for as the display of said attractive trait

Question 20

sperm competition in sexual selection

Answer 20

• competitive process between sperm of two or more different males to fertilize the same egg during sexual reproduction
• humans have intermediate sperm swimming speed and testicle size

Question 21

last man advantage

Answer 21

a reproductive phenomenon where a female is more likely to be fertilized by the last male she engages with

Question 22

mixed mating strategy

Answer 22

• multiple mating strategies across species and individual people
• humans are flexible in terms of the ways we approach mate choice

Question 23

parental investment theory

Answer 23

• risk and reward associated with mate choice
• the amount of investment an individual has to put in to something, in this case reproduction, will dictate behaviours
• examined the biological component to psychological behaviours

Question 24

what guides sexual selection

Answer 24

1. differences in reproductive speed and potential
2. intersex and intrasex competition
3. cues about fertility
4. tied to endocrine status
5. perceptual pressure to notice cues
6. sperm competition