Evolutionary explanations

• What is meant by sexual selection?

  The selection of characteristics increasing reproductive success
• What is the cycle of a relationship?

  Formation -> maintenance -> dissolution (end)
• Why and how do characteristics evolve?

  Characteristics evolve because they have been passed down from one generation to the next via genes.

  This requires the organism:

  • To live to reproductive age
  • To mate successfully
  • To ensure the offspring’s survival
• What is meant by natural selection?

  Process by which organisms are better adapted to their environment tend to survive and reproduce.
• What is meant by sexual selection?

  Ability to find/attract a mate and reproduce successfully. Attributes and behaviours that increase reproductive success are passed onto offspring
• Why is natural selection and sexual selection two different things?

  The characteristics that facilitate reproduction do not necessarily increase survival chances
• What is meant by Anisogamy?

  Difference between male and female sex cells (gametes)
• What is meant by inter-sexual selection?

  The preferences of one sex (usually female) for members of the opposite sex who possess certain qualities. This is referred to as mate choice. Inter-sexual determines intra-sexual
• What is meant by intra-sexual selection?

  Usually males compete with eachother for ,,access’’ to members of the opposite sex, victors mate and pass on their genes and traits to the next generation. This is referred to as mate competition
• What are the three main characteristics for mate choice?

  • good resources
  • Good genes
  • Good parents
• What was Singh (1993) study into what men want?

  • Men like women with a low waist to hip ratio - slimmest part of your waist  /  widest part of your hips
  • This could possibly be linked to fertility
• What is meant by sexual dimorphism?

  The differences in appearances between males and females of the same species, such as in colour shape and size.
• What was Trivers (1972) study into intrasexual and intersexual selection?

  • When one sex (F) invests significantly more than the other (M), members of the latter will compete against eachother to mate with members of the former - intrasexual selection
  • Thus women will be more discriminating than men in their choice of sex partner because the consequences of mating with an unsuitable partner are greater - intersexual selection
• What was Buss (1989) into cultural similarities of sexual selection?

  • Found that males prefer younger, more ,,fertile’’ women
  • Females prefer older men of higher status
  • Males ranked physical attractiveness higher
  • Females ranked ambition higher
  • Buss found that there are universal similarities/differences between the sexes - tethered to evolutionary mechanisms - reproductive traits
• What are some male strategies to increase sexual selection?

  • Courtship rituals
  • Size
  • Sperm competition
  • Mate guarding
  • Sneak copulation
• What are some female strategies to increase sexual selection?

  • Sexy sons hypothesis
  • Handicap hypothesis
  • Courtship
• What is the socio-biological explanation?

  A theory of relationships based on biological determinants
• Why are young women seen as more attractive to men?

  Men see younger woman as more attractive because they tend to be more fertile
• Why are females more attracted to older, higher status men?

  Females are more attracted to men, often older who have access to resources & kindness, as it indicates a willingness to share resources
• Why are symmetrical faces perceived as more attractive?

  Symmetry indicates good health in an individual.

  • As we develop and age, disease, infections and parasites cause imperfection in our appearance (asymmetry)
  • Therefore those that are more symmetrical are seen as having better/stronger immune systems capable of withstanding naturally occurring infections and parasites