| intersexual selection | selection between sexes
preferred by females
quality > quantity |
| why do females prefer quality? | females produce fewer eggs in her lifetime than men produce sperm
women also use more energy to produce eggs than men |
| Fisher Sexy Sons hypothesis | - females mate with males with desirable characteristics
- their sons inherit the "sexy trait". this will increase chances of the sons producing offspring |
| Intrasexual selection | - most common strategy among men
- quantity > quality
- the 'winner' of the competition gets to pass characteristics that contributed to his victory by offspring |
| consequences of intrasexual selection | - dimorphism : obvious differences between males and females. larger males are likely to win physical competitions with other male, being a larger male is an advantage.
- males can also behave aggressively to 'protect' their fertile females from other men. |
| anisogamy | - male reproductive strategy to mate with as many fertile females as possible
- less energy needed to produce sperm and take care of offspring |
| changing of partner preferences | - women can be less cautious as there is higher availability of contraception
- women also do not have to worry about limited time given for fertility as medicine has advanced
- females are also more present in the workforce, so they do not have to be financially dependent on men |
| Singh tested the role of female hip to waist raito in influencing male preference | - 0.7 hip to waist ratio was the most preferred
- wider hips and smaller waist shows signs of fertility but not had kids yet |
