Genetic diversity and natural selection

• What is genetic diversity in a population?

  Different alleles of genes
• Natural selection can only occur if there is genetic diversity
• What is the end result of natural selection?

  Evolution
• Evolution is the change in allele frequency over many generations.
• What is the example used to illustrate antibiotic resistance in bacteria?

  Change in allele frequency
• After natural selection, the proportion of resistant alleles in bacteria increases
• What is the term for structural adaptations in organisms?

  Anatomical
• Physiological adaptations involve chemical reactions within the body.
• Steps in the process of natural selection using the example of fur color in mice

  1️⃣ Genetic diversity exists in fur color due to different alleles.

  2️⃣ Mice with dark fur are less likely to be hunted.

  3️⃣ Dark fur mice survive and reproduce.

  4️⃣ The allele for dark fur becomes more common over generations.
• What is an example of a behavioral adaptation in penguins?

  Huddling together
• What causes new alleles to arise in a population?

  Random gene mutations
• Over many generations, advantageous alleles become more common
• An advantageous allele increases an individual's chances of survival in their environment.
• What is directional selection?

  Extreme trait advantage
• Directional selection occurs only when there is a change in the environment.
• Stabilizing selection maintains the modal trait by eliminating extremes
• What is an example of a trait influenced by stabilizing selection?

  Human birth weight
• Match the type of natural selection with its effect on allele frequency:

  Directional selection ↔️ One extreme trait becomes dominant

  Stabilizing selection ↔️ Modal trait remains most common
• In stabilizing selection, the range of alleles for a trait decreases over time.