Relationships- Evolutionary Explanations For Partner Preferences

Question 1

• human reproductive behaviour is driven

Answer 1

by the need to survive and reproduce. Both males and females need to ensure they have children and those children survive to adulthood.

Question 2

Sexual selection acts on

Answer 2

creatures’ ability to compete with others of the same sex (often males) for mates and to attract the opposite sex (often females).Therefore genes that provide a reproductive advantage will be selected for, increasing in the human gene pool.

Question 3

• Intersexual Selection:

Answer 3

AKA “mate choice” When members of one sex (typically females) choose mates of the other sex to reproduce with based on specific traits. In most animals, including humans, it generally is females who choose because females often invest more in offspring (time, energy, resources) than males do, making them more selective, picking the highest quality mate from the wide selection of mates available to them.

Question 4

• Intrasexual Selection:

Answer 4

AKA “mate competition” when members of the same sex (typically males) compete with each other to access and attract members of the opposite sex. This could be displays of physical power, social dominance, or resources. In most animals, including humans, males compete due to low investment costs and a lack of parental certainty; males compete for access to as many members of the other sex as possible.

Question 5

• Male-Female dimorphism:

Answer 5

enhanced secondary sexual characteristics are selected for by both genders, making these physical characteristics more common in the population.

Question 6

• Females look for:

Answer 6

Qualities that will help raise a child to adulthood: resources/money, physical characteristics linked to dominance (tall/healthy), V-shaped chest.

Question 7

• Males look for:

Answer 7

Qualities of fertility that indicate the production of healthy offspring: Large breasts, young (facial features, a body shape of 0.7 hip to waist ratio, indicates sexual maturity but not pregnant.

Question 8

The Evolutionary Approach

Answer 8

• According to Darwin’s (1859) theory of evolution, natural selection influences the way that species change over time and become increasingly better adapted to their environment
• Any characteristics that maximise an individual’s ability to survive and reproduce successfully are highly adaptive and likely to be ‘naturally selected’.
• Individuals with these genes go on to form successive generations

Question 9

Why do Characteristics evolve?

Answer 9

because they have been passed from one generation to the next via the genes

Question 10

This requires the organism:

Answer 10

• To live to a reproductive age
• To mate successfully
• To ensure the offspring’s survival

Question 11

Sexual selection

Answer 11

A view that competition for mates between individuals of the same sex affects the evolution of certain traits

Question 12

• If a characteristic increases the individual’s chances of reproduction, this characteristic will

Answer 12

be adaptive because that animal will have more offspring.

Question 13

Natural selection involves

Answer 13

Survival of the fittest

Question 14

Sexual selection involves

Answer 14

Survival of the sexiest

Question 15

Natural selection

Answer 15

• Ability to survive in a particular environment (fitness)

Question 16

• Sexual selection

Answer 16

• Ability to attract/find a mate and reproduce successfully

Question 17

Are natural and sexual selection separate processes?

Answer 17

• These are separate processes - the characteristics that facilitate reproduction do not necessarily increase survival chances

Question 18

Sexual dimorphism

Answer 18

In many species, males have characteristics le.g. brighter colouration, exaggerated tails) that serve to attract females
• Suggests that males are competing for the attention of females
• Suggests that, in many species, females do the choosing

Question 19

Darwin 1871

Answer 19

“Sexual Selection depends not on a struggle for existence in relation to other organic beings or external conditions, but a struggle between the individuals of one sex generally the males, for possession of the other sex”

Question 20

How many types of sexual selection are there ?

Answer 20

2
Inter sexual selection
Intra sexual selection

Question 21

Males produce sperm in thousands at relatively little physiological cost it’s quick and easy

Answer 21

Therefore, their best strategy is to mate with many females, because this should result in the maximum number of offspring

Question 22

Females produce eggs, each of which contains a store of food for the growing emoryo

Answer 22

This incurs some cost to the female and so eggs are not generally produced in thousands

Question 23

Evaluation Trivers (1972)

Answer 23

• According to Trivers (1972), when one sex (f) invests considerably more than the other (m), members of the latter (m) will compete among themselves to mate with members of the former (f). - Intrasexual Selection
• Thus, women will be more discriminating than men in their choice of sex partner because the consequences of mating with an unsuitable partner are greater.- Intersexual Selection

Question 24

Anisogamy

Answer 24

Refers to the differences between males and females - different sex/reproductive cells cells.
Because if anisogamy there is a difference in the level of investment in reproduction

Question 25

✅
Dunbar and Waynforth

Answer 25

Dunbar and Waynforth (1995) Used content analysis on 900 dating ads. Found 42% of males were looking for “youthful” mates compared to 25% of females. In their adverts, men were likelier to emphasise their economic status; women were likelier to emphasise their looks. This supports the Evolutionary theory’s explanation of females being more attracted to status and resources, with men advertising these and males looking for females capable of reproduction.

Question 26

✅
Clarke and heartfield (1989)

Answer 26

Male and female student researchers asked other students one of three questions. “will you go out with me tonight?”, “Will you go back to my house” or “Will you have sex with me”. Found 50% of both genders agreed to a date, 0% of females agreed to sex, compared to 75% of males. This supports the concepts of intra and inter-sexual selection that males will attempt to sleep with as many women as possible, while women will be more selective.

Question 27

✅
Cunningham (1986)

Answer 27

Research by Cunningham (1986) found men were most attracted to images of youthful faces (large eyes, small noses and chins, research by Singh (1993) shows a cross-cultural preference for a 0.7 hip-to-waist ratio.

Question 28

❌ double standard

Answer 28

The evolutionary approach could be criticised as legitimatising a gender double standard between men and women. Sexual differences may have been exaggerated, suggesting Alpha bias. Research in this area could be seen as socially sensitive.
Findings could be used as a justification for shaming women for their sexual behaviour.

Question 29

❌ homosexual

Answer 29

Evolutionary explanations for sexual selection can also be criticised for not explaining homosexual partner preferences.

Question 30

Zahavi (1997)

Answer 30

According to Zahavi’s (1997) hypothesis, a male adornment such as a long tail is a handicap. The argument is that a male bird that is able to survive despite having a significant handicap is likely to be genetically superior to other birds.
Thus, females who prefer handicapped males may be selecting those who tend to possess good genes for survival. Thus this theory is also called the ‘good genes’ theory. Consider this example. Suppose two men are running a race around a track at the same speed, one of them is carrying a heavy load. We would assume that the man handicapped by the load is stronger and fitter than the other man.
In human males the handicap is testosterone. Testosterone is responsible for masculine features like squarer face-shapes, stronger jaw lines and less prominent cheekbones. lestosterone is a handicap to the male because although it might give him masculine features it actually suppresses the immune system (which nelps protect us against illness and disease. so it a male can survive despite this handicap it indicates to the female he must be of a good genetic quality.

Question 31

The spice finch

Answer 31

The spice finch momomorphic