Causes of Genetic Variation

a) DNA Mutation:

• A mutation is a change in the DNA sequence.
• These variations in gene sequences can sometimes be advantageous to an organism.
• Most mutations that result in genetic variation produce traits that confer neither an advantage or disadvantage.

b) Gene Flow:

• Also called gene migration, gene flow introduces new genes into a population as organisms migrate into a new environment.
• New gene combinations are made possible by the availability of new alleles in the gene pool.

c) Sexual Reproduction:

• Sexual reproduction promotes genetic variation by producing different gene combinations.
• Meiosis is the process by which sex cells or gametes are created.
• Genetic variation occurs as alleles in gametes are separated and randomly united upon fertilization.
• The genetic recombination of genes also occurs during crossing over or the swapping of gene segments in homologous chromosomes during meiosis