The Evolution of Populations

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Slide 39

Why Natural Selection Cannot Fashion Perfect Organisms

Selection can act only on existing variations.

Evolution is limited by historical constraints.

Adaptations are often compromises.

Chance, natural selection, and the environment interact.

Slide 40

You should now be able to:

Explain why the majority of point mutations are harmless.

Explain how sexual recombination generates genetic variability.

Define the terms population, species, gene pool, relative fitness, and neutral variation.

List the five conditions of Hardy-Weinberg equilibrium.

Slide 41

Apply the Hardy-Weinberg equation to a population genetics problem.

Explain why natural selection is the only mechanism that consistently produces adaptive change.

Explain the role of population size in genetic drift.

Slide 42

Distinguish among the following sets of terms: directional, disruptive, and stabilizing selection; intrasexual and intersexual selection.

List four reasons why natural selection cannot produce perfect organisms.