Population Genetics

• Population is the group of individuals who share a common set of genes or live in the same geographic are
• Gene pool is the set of all genes in any population and usually of a particular species
• Population genetics is about concerning genetic traits in large number of individuals
• Non random mating is an individuals of many species have a choice about which partners to mate with. It alters genotype frequency but not allele frequency in a population and it also increases the frequency of homozygous in a population and decreases the frequency of heterozygous.
• 2 types of non random mating: Disassortative & Assortative
• Allele frequencies is a frequency of occurrence or proportions of different alleles of a particular gene in a given population
• p means dominant
• q means recessive
• Genotype frequencies is a number of individuals with a given genotype divided by the total number of individuals in the population
• p2 means homozygous dominant
• q2 means homozygous recessive
• 2pq means heterozygous
• Hardy -Weinberg Principle: Godfrey Hardy & Wilhelm Weinber
• The key to Hardy-Weinberg problems lies in the homozygous recessive individuals
• Selection can be a major force driving allele frequency change and lead to adaption
• Mutation creates new alleles in a gene pool. Is the origin of new genetic capabilities in populations by means of spontaneous heritable changes in genes
• Migration is a gene flow from other populations can alter allele frequencies. A movement of organisms among subpopulations within a larger population
• Evolution changes in allele frequencies
• Genetic Drift causes random changes in allele frequency especially in small populations
• Natural Selection is resulting from the different abilities of organisms to survive and reproduce in their environment and a primary proves by which population of organisms become progressively better adapted to their environments.
• Random Genetic drift produces random change in allele frequencies, change to a population's gene pool by chance and can have a major impact in small populations
• States that allele and genotype frequencies in a population will remain constant form generation to generation in the absence of other evolutionary influences

  Hardy-Weinberg Principle