Podcast
Questions and Answers
What is microevolution primarily concerned with?
What is microevolution primarily concerned with?
Which force of evolution introduces new alleles into a population?
Which force of evolution introduces new alleles into a population?
What type of natural selection favors intermediate phenotypes and reduces genetic diversity?
What type of natural selection favors intermediate phenotypes and reduces genetic diversity?
Which statement accurately describes balancing selection?
Which statement accurately describes balancing selection?
Signup and view all the answers
In the context of fitness, what does absolute fitness refer to?
In the context of fitness, what does absolute fitness refer to?
Signup and view all the answers
What occurs when relative fitness w is greater than 1?
What occurs when relative fitness w is greater than 1?
Signup and view all the answers
Directional selection is characterized by which of the following?
Directional selection is characterized by which of the following?
Signup and view all the answers
Genetic drift is especially significant in which type of populations?
Genetic drift is especially significant in which type of populations?
Signup and view all the answers
Study Notes
Evolution
- A change in allele frequencies in a population over time.
- Microevolution involves small-scale changes within a species or population.
- Macroevolution involves large-scale changes leading to the formation of new species or taxonomic groups.
Four Forces of Evolution
- Mutation: Introduces new alleles that can be beneficial, detrimental, or neutral.
- Gene Flow (Migration): Movement of alleles between populations due to migration.
- Genetic Drift: Random changes in allele frequencies, especially significant in small populations.
- Natural Selection: The only evolutionary force consistently increasing adaptation. Favors traits that enhance survival and reproduction.
Natural Selection
- A process where certain phenotypes increase reproductive success, leading to changes in allele frequencies.
- Directional Selection: Favors one extreme phenotype, causing allele frequencies to shift in one direction (e.g., antibiotic resistance).
- Stabilizing Selection: Favors intermediate phenotypes and reduces genetic diversity (e.g., optimal birth weight).
- Disruptive Selection: Favors extreme phenotypes at both ends, potentially leading to speciation (e.g., beak size in seedcrackers).
- Balancing Selection: Maintains genetic diversity by favoring heterozygotes or rare alleles (e.g., heterozygote advantage in sickle-cell anemia).
Fitness
- Absolute Fitness: The total number of offspring an individual contributes to the next generation.
- Relative Fitness (w): The fitness of a genotype compared to the population average.
- If relative fitness w > 1, the allele increases in frequency.
- If w = 1, the allele changes randomly.
- If w < 1, the allele decreases in frequency.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Test your understanding of evolution, including microevolution and macroevolution. Explore the four forces of evolution, such as mutation and natural selection, and how they impact allele frequencies in populations. This quiz covers the fundamental concepts that drive evolutionary change.
