Natural Selection and Evolution in Real Time

Evolution by Selection and Inheritance

Fitness: The Currency of Selection

Positive Selection: The Spread of Beneficial Mutations

BOX 5A Evolution by Selection on a Single Locus

• The rate of adaptation
• Chance and adaptation: The probability that a beneficial mutation spreads

Evolutionary Side Effects

• Hitchhiking: When one allele goes for a ride with another

When Selection Preserves Variation

• Overdominance
• Other forms of balancing selection

Selection That Favors the Most Common

• Underdominance: When heterozygotes suffer
• Positive frequency-dependent selection

The Evolution of a Population’s Mean Fitness

• The fundamental theorem of natural selection and the adaptive landscape

Deleterious Mutations

• A mutation-selection balance
• The mutation load