Ppt ng mechanisms of evolution

• Artificial Selection


  Intentional breeding of plants or animals. People get to select which organisms to reproduce.
• Natural Selection


  Process through which populations of living organisms adapt and change. Heritable traits that help organisms survive and reproduce become more common in the population over a period of time.
• Genetic Drift


  Allelic drift/Sewall Wright Effect. Change in the frequency of a gene variant (allele) in a population due to random sampling of organisms. In contrast with Natural Selection.
• Mutation


  Change in the DNA
• Recombination


  Pieces of DNA are broken and recombined to produce new combinations of alleles. Crossing-over during Meiosis.
• All of these mechanisms can cause changes in the frequencies of genes in populations, and so all of them are mechanisms of evolutionary change. However, natural selection and genetic drift cannot operate unless there is genetic variation, that is, unless some individuals are genetically different from others.