Evolutionary Explanations - Anisogamy Flashcards
What is the part of sexual selection that anisogamy is responsible for?
Men and women not wanting the same thing.
What is anisogamy?
The differences between the number of sperm and eggs produced.
What does anisogamy cause?
Differences in sexual selection strategies between males and females.
What is the difference between males and females in terms of the number of sperm and eggs they have?
Sperm - Many.
Eggs - Relatively few.
What is the difference between males and females in terms of the energetic cost of having sperms or eggs?
Males - Energetically cheap.
Females - Energetically expensive.
What does natural selection favour men doing?
Maximising the number of potential pregnancies by having sex with as many females as possible.
Why does natural selection favour men maximising the number of potential pregnancies?
Because they cannot be sure of paternity.
To have a better chance at one good baby.
What does anisogamy give rise to in terms of partner preference?
Two different mating strategies.
What are the two different mating strategies that are given rise to by anisogamy?
Intrasexual selection.
Intersexual selection.
Is intrasexual selection a preferred strategy for men or women?
Men.
What is intrasexual selection (using men to describe)?
When males compete with other males to get access to better females.
How do traits get passed on with intrasexual selection?
The traits that lead to successful mating in these contests get passed on.
In intrasexual selection, what is one thing that will make a female ‘better’?
Youthfulness, they seem more fertile.
Is intersexual selection a preferred strategy for men or women?
Women.
What is intersexual selection?
The preference for certain traits in the opposite sex,
What causes the preferences for certain traits within intersexual selection?
Indications that they have ‘good genes’ meaning they would produce successful offspring and have the ability to support and protect the offspring.
Under which sexual selection does the ‘sexy sons hypothesis’ come?
Intersexual selection.
What does the sexy sons hypothesis claim?
Women do not sleep with attractive men because they find them attractive, its because they want attractive children, then others will find these children attractive in the future.
What is a slightly more technical explanation of the sexy sons hypothesis?
A female mates with a male who has a desirable characteristic, this ‘sexy’ trait is passed onto her son, this increases the likelihood that successful generations of females will mate with her offspring.
When choosing a long term partner, who will females be attracted to?
A male who will stick around, look after her and be attractive.
Why are women seeking long term partners that will stick around and be attractive?
Because of the output of parental investment (the cost of having a child and pregnancy).
When choosing a long term partner, who will males be attracted to?
Demonstrate fertility/
Why are men seeking long term partners that demonstrate fertility?
If a man is going to be stuck with one women (which they don’t want anyway) then it needs to be someone fertile so they can still have the chance to have lots of children.
