Evolutionary explanations

• Anisogamy 


  is the difference male/female reproductive gametes.
• Female gametes 


  are eggs/ova - these take a lot of energy to produce, limited supply of eggs and must have high investment in the reproduction compared to the male.
• Male gametes 


  is sperm - these take little energy to produce, abundant supply which is quickly replenished and they invest little into reproductive.
• Inter-sexual selection:


  -Females are highly selective with who they reproduce/combine genes with who they reproduce/combine genes with.

  -The evolved preferences women look for in a man is strong, tall, muscular for survival of the offspring so they can protect the mother when older. If they can provide resources and have a symmetrical face which indicates good genes.
• Intra-sexual selection


  -Males must compete with other males for mating access to females.

  -Males have evolved to 'mate guarding' behaviours, protective and prevent 'cuckoldry' which is where males ward off other males who seek sexual activity.

  -Makes evolved preferences are neonate features: big eyes, small nose and full lips. Look younger which indicates fertility. If they have a 0.7 W:H ratio and a symmetrical face.