5-6. Genetic Variation

From the Stage 2 SACE Biology course outline, this video discusses: - Mutation is a permanent change in the sequence of DNA nucleotides and is the ultimate source of genetic variation in a species. - In a species that reproduces sexually there are additional sources of genetic variation. • Explain the sources of genetic variation in a species that reproduces sexually. - A gene pool comprises all the genetic information in an interbreeding population. • Recognise that a large gene pool indicates considerable genetic diversity and is found in populations that are more likely to survive selection pressures. - Natural selection is a process in which organisms that are better adapted to their environment are more likely to survive and produce offspring. • Explain how natural selection results in evolution by causing a change in the frequency of alleles in a population. Evolutionary changes are affected by other factors besides selection, including: – sexual reproduction – genetic drift.