Genetic biodiversity can be measured by measuring polymorphism. Polymorphic genes have more than one allele.Most genes are not polymorphic. Most genes are monomorphic. This ensures that the basic structure and characteristic of species remains constant.A proportion of genes are polymorphic. The greater the proportion of polymorphism, the greater the genetic biodiversity within the population.Gel electrophoresis can be used to analyse the DNA. The DNA is cut into fragments using restriction enzymes and they are placed in a well between positive and negative electrodes.The DNA moves towards the positive electrode.Genetic biodiversity is measured using the proportion of polymorphic gene loci. A locus is polymorphic if it has two or more alleles and the most common allele has a frequency below a certain threshold (typically ≤ 95% or ≤ 99%).The formula used is:
| Number of polymorphic gene loci Total number of loci investigated |