relationships

• sexual selection

  am evolutionary explanation of partner preference - attributes or behaviours that increase productive success are passed on and may become exaggerated over succeeding generations of offspring
• human reproductive behaviour

  refers to any behaviours which relate to opportunities to reproduce and thereby increase the survival chances of our genes
• anisogamy

  refers to difference between males and female sex cells
• what are the two different types of mating strategy?

  inter-sexual selection

  intra-sexual selection
• which mating strategy is the preferred strategy of the female?

  inter-sexual selection
• explain inter-sexual selection

  . preferred strategy of the female

  
  

  . quantity over quality

  
  

  . ova are rarer than sperm and require a greater energy to produce

  
  

  . Trivers (1972) says that the female makes a greater investment of time, commitment and other resources before, during and after the birth of her offspring

  
  

  . both sexes are choosy because both stand to loose if they invest resources in substandard partners - but the consequences of making a wrong choice of a partner are much more serious for the female than for the male - pays for her to be especially choosy

  
  

  . females optimum mating strategy is to select a genetically fit partner who is able and willing to provide resources - this leaves the men competing for the opportunity to mate with the fertile female

  
  

  . female preference for a fit male which determines which features are passed on to the offspring -eg. if height is considered an attractive trait, then over successive generation of females, it would increase in the male population because females would mate with tall males, and over time produce sons who are taller with each each generation and produce daughters who have a greater preference for taller partners. This is known as the runaway process
• explain intra-sexual selection

  . preferred strategy of the male

  
  

  . quantity over quality

  
  

  . it refers to competition between males (intra) to be able to mate with a female

  
  

  . the winner of the competition reproduces and gets to pass on to his offspring the characteristics that contributed to his victory