Sexual Selection and Reproductive Behaviour

• What do traits that increase reproductive success (e.g. strength and height) confer?

  It confers an adaptive advantage. Individuals with these traits are more likely to survive and pass on these genes. It ensures survival of their gene pool
• What is intra-sexual selection?

  Intra-sexual selection is where traits increase the 'attractiveness' and/or induce members of the opposite sex to mate with them. For example, female mate choice- females are more choosy because parental investment is much higher, and unlike sperm, ova are limited (this is evolutionary, choice is not conscious)
• What is inter-sexual selection?

  Inter-sexual selection is where traits allow an individual to compete with members of the same sex for access to mating opportunities. For example male-male competition
• What is sexual dysmorphism?


  Sexual dysmorphism is how males are bigger than females
• What is anisogamy? 


  Anisogamy is where differences in male and female sex cells result in different strategies for reproductive success- sperm is potentially unlimited and ova are limited. This explains the female preference for a long courtship- to ensure resources keep coming so that offspring have the best chance of survival
• What supporting evidence did Clark and Hatfield find about female mating choice?

  Clark and Hatfield asked m/f students to approach members of the opposite sex on campus and ask questions, including 'would you go to bed with me?'. 75% of males agreed, but 0% of females suggesting because of limited ova, females need to be choosier with partner selection as the consequences of a poor quality mating would be higher, supporting the idea of inter-sexual selection
• How is anisogamy consistent with Buss' study?

  Buss' study of over 10,000 adults, which found females universally placed more importance on resource-based traits, and males preferred younger females (fertility)
• How does Kenrick's findings oppose the idea that males look for the highest level of fertility?

  Kenrick found that teenage males were most attracted to women who were 5 years older than them, which doesn't support the idea that males are looking for the highest level of fertility
• How does the evolutionary theory have problems with its temporal validity?

  It is not relevant to todays society- changes in social attitudes and expectations (women can work, pill means not all mating results in offspring) means the theory lacks temporal validity. Furthermore, evolutionary theory is hard to apply to non-heterosexual relationships and thus cant explain the behaviour of many people