Relationships

Question 1

What is sexual selection?

Answer 1

Sexual selection is the view that any physical trait that enhances reproductive success that’ll be passed down overtime through evolution.

Question 2

What did Darwin propose?

Answer 2

That animals possess features that makes them attractive to members of the opposite sex and allow them to compete better with members of the same sex.

Question 3

What is anisogamy?

Answer 3

Anisogamy is the difference between female eggs and male sperm.

Biologically, males are different to females. Males can produce millions of male sperm with little physiological cost, whereas females can only produce one egg per month.

Question 4

What’s a consequence of anisogamy?

Answer 4

There’s no shortage of fertile males but a fertile female is rare.

Question 5

What are the two different types of sexual selection?

Answer 5

1) Intrasexual selection

2) Intersexual selection

Question 6

What is intersexual selection? Explain it fully according to FEMALES

Answer 6

• Sexual selection BETWEEN the sexes.
• It is the preferred strategy of the female as they prefer quality over quantity.
• The females mating strategy is to select a partner who’s genetically fit partner who’s able to provide resources (money, height, humour). This is because females are especially choosy of their partner because they make a greater investment in terms of time & commitment before and after birth. This leaves males competing for the opportunity to mate with the female.

Question 7

What is Ronald Fisher’s Sexy Son hypothesis?

Answer 7

A female mates with a male who has desirable characteristics (ie height). This characteristic is passed onto her son and increases the likelihood of females wanting to mate with her ‘sexy son’.

So with height, if that’s considered attractive, over generations height would increase in the population because females mate with tall males only and produce sons who are taller, and daughter who prefer tall men.

Question 8

What is intra-sexual selection? (12 marks)

Answer 8

• This is selection WITHIN the sexes.
• This is the preferred strategy of the male.
• The male’s mating strategy is to mate with as many fertile females as possible. This is because of the minimal energy required to produce sperm and the lack of responsibility the male has over the baby. Males are able to pass on his offspring and the characteristics that enabled him to be the desired male in the first place.

Question 9

What’s a consequence of intra-sexual selection?

Answer 9

A behavioural consequence of this competition is a preference for a fertile looking females ie hourglass bodies (wide hips = fertile)