Questions and Answers
What is the definition of evolution?
What does microevolution refer to?
Only the genetic component of variation in populations is relevant to natural selection.
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What should we look at to determine if a population is evolving?
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What is a genotype frequency?
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What is the definition of allele frequency?
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What produces genetic variation?
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What are the main causes of microevolution?
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What is gene flow?
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What is genetic drift?
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The bottleneck effect increases genetic variation in a population.
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What is the founder effect?
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Study Notes
Evolution and Microevolution
- Evolution entails changes in genetic characteristics of a population over time; individuals do not evolve.
- Microevolution refers to small-scale evolutionary changes and involves shifts in allele frequencies within a population across generations.
Population and Genetics
- A population consists of individuals of the same species coexisting in the same location and is the smallest biological unit able to evolve.
- Population genetics studies the genetic makeup and evolutionary dynamics of populations over time.
Genetic Variation
- Individual variation exists widely within populations, but not all variation is heritable; only genetic differences impact natural selection.
- To assess if a population is evolving, monitoring allele frequencies is essential.
Allele and Genotype Frequencies
- Genotype frequency indicates the proportion of specific genotypes (e.g., AA, Aa, aa) within a population.
- Allele frequency measures the occurrence of specific alleles (e.g., A or a) in a population.
Mechanisms of Microevolution
- Microevolution involves generation-to-generation shifts in allele frequencies, with variation among individuals, much of which is heritable.
- Genetic variation arises from mutations and sexual recombination, which alters allele arrangements during meiosis.
Causes of Microevolution
- Primary drivers of microevolution include gene flow, genetic drift, mutations, and natural selection.
Gene Flow and Genetic Drift
- Gene flow signifies genetic exchange between populations, reducing genetic diversity.
- Genetic drift represents stochastic changes in a small population's gene pool, influencing evolution through chance events.
Effects of Genetic Drift
- Genetic drift diminishes genetic variation in small populations, potentially leading to allele fixation more quickly than in larger groups.
- It can fix alleles that are neutral, harmful, or beneficial; natural selection is the only consistent mechanism for adaptive evolution.
Bottleneck and Founder Effect
- The bottleneck effect results from severe population size reduction, threatening survival and generally decreasing genetic variation.
- The founder effect describes genetic drift occurring when a small group establishes a new colony, influencing the genetic structure of that population.
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Description
Test your understanding of evolution and microevolution concepts. This quiz covers population genetics, genetic variation, allele frequencies, and the mechanisms driving evolutionary changes. Perfect for students learning about evolutionary biology and genetics.
