Investigating Diversity

• INVESTIGATING GENETIC DIVERSITY:

  • COMPARING CHARACTERISTICS: the frequency of measurable and visible characteristics can be compared between individuals (eg the differences of heights in an age group or the differences in brain sizes between humans and chimpanzees)
• INVESTIGATING GENETIC DIVERSITY:

  • DNA BASE SEQUENCE; Can be compared between individuals. The greater differences, the more distantly related the 2 individuals are (eg an individual will have a similar base sequence compared to their parents vs a random member of the population)
• INVESTIGATING GENETIC DIVERSITY:

  • mRNA BASE SEQUENCE: The sequences of bases in mRNA can be compared between individuals. The greater the differences in the base sequences between the two individuals, the more distantly related the 2 individuals are
• INVESTIGATING GENETIC DIVERSITY:

  • AMINO ACID SEQUENCE: The sequence of amino acids in proteins can be compared between individuals. The greater the difference in amino acid sequence between 2 individuals. The more distantly related they are (eg Cytochrome C= an electron carrier protein that forms a part of the electron transport chain in respiration, there is a 33% difference for cytochrome C in the amino acid sequence between mammals and insects)
• GENE TECHNOLOGIES:

  • VISIBLE CHARACTERISTICS: The frequency of characteristics in a population was used as an indirect measure of diversity (e.g. the number of different coat colours of horses & the number of individuals of horses with each coat colour would indicate genetic diversity). It was limited as it was polygenic (coded for b more than one gene, not discrete from one another) and characteristics can be changed by the environment (eg height can be genetic but also influenced by diet). Used before gene technologies were invented.
• GENE TECHNOLOGIES:

  GENE TECHNOLOGIES: Allow the alleles in an individual to be directly measured & base sequence in DNA to be read (they cause genetic diversity). Gene technologies allow genetic diversity to be measured (e.g. number of different alleles for a single gene and the number of individuals with each allele directly shows genetic diversity). Different nucleotide bases are tagged with with dyes to produce a pattern of colours. mRNA= complementary to DNA, amino acid sequence= determined by mRNA so can also be used to measure genetic diversity.
• INTERSPECIFIC VARIATION: Variation between species

  INTRASPECIFIC VARIATION: Variation between organisms of the same species
• INVESTIGATING VARIATION:

  • RANDOM SAMPLING: Investigates the variation in a population without spending lots of time counting every individual. Ensures the sample accurately represents the total variation of the species, without human bias . Random sampling is applied by assigning individual numbers and randomly selecting the numbers (eg with a computer program)
  • RANDOM SAMPLING METHOD: 1)Divide the area into a grid of numbered lines 2) Using random numbers obtain coordinates 3) Take samples at the coordinates
• INVESTIGATING VARIATION:

  • HUMAN BIAS:eg sampling bias- may take samples in a dry rather than muddy area unintentionally. Chance- individuals chosen might be not representative of whole population
  • NORMAL DISTRIBUTION CURVE: Mean= max height of the curve, standard deviation= measure of the width of the curve
  • STANDARD DEVIATION; Shows how far away the values are from the mean: 
• INVESTIGATING VARIATION: