Relationship between sexual selection & human reproductive behaviour

Question 1

What is sexual selection?

Answer 1

Genes which are advantageous for survival are naturally selected. Genes that promote successful reproduction are selected.

Question 2

What is anisogamy?

Answer 2

Difference between male & female sex cells. Male cells (sperm) are plentiful & relatively “cheap”. Female cells (ova) are “expensive” - require more energy to produce them. Differences give rise to 2 different mating strategies.

Question 3

What is inter-sexual selection?

Answer 3

Strategies males use to select females or females to select males.

Question 4

What does Trivers say about inter-sexual selection?

Answer 4

Females make a greater investment of time, commitment & other resources during & after birth of offspring. Consequence of picking a wrong partner is more severe for females, so they are more selective.

Question 5

What is the optimum female mating strategy?

Answer 5

Select a genetically fit partner, who is able to provide resources.

Question 6

What is the runway processes?

Answer 6

Preferences of both sexes determine attributes that are based on. E.g. if height is considered an attractive male trait, it increases in the male population over generations because females choose the tallest males - trait becomes exaggerated. Over time this leads to taller & taller men being selected.

Question 7

What is Fisher’s sexy sons hypothesis?

Answer 7

A female who mates with a male, who has a certain characteristic, then her sons will inherit the “sexy” trait in the future. Preference for this “sexy” trait is perpetuated.

Question 8

What is intra-sexual selection?

Answer 8

Males compete with other males for mates. Males compete for access to females, as male sperm is plentiful but fertile females are a limited resource & are choosy.

Question 9

What traits are passed on to offspring?

Answer 9

“Winning” traits.

Question 10

What do females look for:

Answer 10

Tall, upside down triangle shape.

Question 11

What do males look for:

Answer 11

Waist to hip ratio, signs of youthfulness ( appear more fertile).

Question 12

What is dimorphism?

Answer 12

Males and females end up looking very different. E.g. males are tall and females are short.

Question 13

What bad things can be passed on?

Answer 13

Behavioural consequences - traits to help win competitions, e.g. deceitfulness, aggression

Question 14

Strength: Research support got inter-sexual selection

Answer 14

In Clark & Hatfield’s study students asked other students “I have been noticing you around campus. I find you very attractive. Would you go to bed with me tonight?” No female students agreed but 75% of males did. Supports view that females are choosier on partner preferences & males have evolved a different strategy to ensure reprodructive success.

Question 15

COUNTERPOINT: strength: Research support got inter-sexual selection

Answer 15

Buss & Schmitt claim sexual selection theory is simplistic because it suggests 1 strategy is adaptive for all males & another is adaptive for all females. Instead, both have similar preferences when seeking long-term relationships (e.g. loyalty, kindness).

Question 16

Strength: research support for intra-sexual selection

Answer 16

Buss surveyed over 10 000 adults in 33 countries asking about those attributes predicted to be important in partner preferences. Found females valued resource related characteristics, e.g. good financial prospects, more than wales did. Males seek signs of reproductive capacity (e.g. physical attractiveness & youth). Findings reflect consistent sex differences in preferences, supporting predictions from sexual selection theory.