Sexual selection and human reproductive behaviour

  • Sexual selection and human reproductive behaviour:
  • AO1:
  • Sexual selection - Anisogamy - differences between male and female sex cells:
  • Male cells (sperm) are small, mobile and continuously produced from puberty to old age. Female cells (eggs) are larger, static and produced at intervals for a limited number of years. Consequences of anisogamy is that there are plenty of fertile males but fewer females. This gives rise to different mating strategies - inter-sexual and intra-sexual. 
  • Inter-sexual selection:
  • Selection of mates between sexes (females selecting males or males selecting females).
  • Females make a greater investment of time, commintment and other resources before, during and after birth. Females need to be choosier than males so seek a male who will provde healthy offspring and support them with resources. Preferences of both sexes determine attributes that are passed on - e.g. if height is a genuine marker of fitness in males, the females who choose the tallest mates will have greater reproductive success and innate preferences are passed on. Over time this leads to taller and taller men being selected (runaway process). 
  • Intra-sexual selection:
  • Selection of mates within sexes (e.g. males competing with other males for mates). 
  • Males do best if they reproduce as frequently as possible. Competition is necessary as females are a limited reource and are choosy. Males who compete


No comments have yet been made