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.