Chapter 13

Key Concepts in Evolution

• Introduction to Evolution

  • WHO's 1960s malaria campaign used DDT.

  • Mosquito populations evolved resistance to DDT.

  • Chloroquine resistance in malaria parasites mirrors this pattern.

  • Evolution provides foundational knowledge across biology.

• Darwin's Theory of Evolution

  • Charles Darwin's work, "On the Origin of Species," introduced natural selection.

  • Evolution involves descent with modification, connecting species through common ancestry.

  • Darwin's theory generates hypotheses supported by significant evidence.

• Evidence from Fossils

  • Fossils document life forms, showing evolution and extinction patterns.

  • Transitional fossils demonstrate links between extinct and modern species.

• Homologies in Evolution

  • Homologies showcase structural similarities indicating common ancestry.

  • Vestigial structures exemplify remnants of past functions.

  • Evolutionary trees visualize descent patterns among species.

• Natural Selection

  • A key mechanism driving evolution.

  • Influenced by artificial selection – breeding traits within species.

  • Focuses on heritable traits and populations rather than individual organisms.

  • Natural selection impacts phenotype distribution (stabilizing, directional, disruptive).

• Microevolution Factors

  • Influenced by mutation, genetic drift, and gene flow.

  • Genetic drift effects: bottleneck and founder effects.

  • Natural selection leads to adaptive evolution while maintaining genetic diversity through mechanisms like heterozygote advantage.

• Challenges of Evolution

  • Evolution doesn't produce perfection. It acts on existing variations and historical constraints.

  • Examples include adaptations often being compromises rather than ideal functions.