11.4

• Simpson's Biodiversity Index measures the diversity of a habitat considering both species richness and evenness
• Simpson's Biodiversity Index: $D=$$1-[E(n/N)2]$
• D = diversity, n = no. of individuals of one species, N = total no. of individuals of all species
• A High value of Simpson's Index means a diverse & rich biodiversity
• A low value of Simpson's Index means low biodiversity
• Positive biodiversity: Gene mutations, Interbreeding with other populations
• Negative biodiversity: selective breeding, captive breeding programmes, rare breeds, artificial cloning, natural selection, genetic bottlenecks, founder effect, genetic drift
• Genetic biodiversity is the sum of different alleles in a population
• Allele frequency is how often a particular allele occurs within a population
• Population Bottlenecks are ecological events that reduce population sizes dramatically and can lead to alleles being over-represented/eliminated from the surviving population
• The Founder effect is when a small group of individuals migrate and become isolated from the population, so may evolve differently with less genetic diversity & struggle with inbreeding
• A Polymorphic gene is a gene with more than two possible alleles
• A Monomorphic gene is a gene for which only one allele exists