Podcast
Play an AI-generated podcast conversation about this lesson
Questions and Answers
What is the definition of evolution?
What is the definition of evolution?
- Change in the genetic characteristics of individuals
- Change in the genetic characteristics of a population of organisms over time (correct)
- A process that only occurs in animals
- Change in the physical characteristics of organisms
What does microevolution refer to?
What does microevolution refer to?
- Large-scale evolutionary changes
- Evolutionary changes that occur only in animals
- Immediate changes in physical traits
- Changes in allele frequencies over time (correct)
Only the genetic component of variation in populations is relevant to natural selection.
Only the genetic component of variation in populations is relevant to natural selection.
True (A)
What should we look at to determine if a population is evolving?
What should we look at to determine if a population is evolving?
Signup and view all the answers
What is a genotype frequency?
What is a genotype frequency?
Signup and view all the answers
What is the definition of allele frequency?
What is the definition of allele frequency?
Signup and view all the answers
What produces genetic variation?
What produces genetic variation?
Signup and view all the answers
What are the main causes of microevolution?
What are the main causes of microevolution?
Signup and view all the answers
What is gene flow?
What is gene flow?
Signup and view all the answers
What is genetic drift?
What is genetic drift?
Signup and view all the answers
The bottleneck effect increases genetic variation in a population.
The bottleneck effect increases genetic variation in a population.
Signup and view all the answers
What is the founder effect?
What is the founder effect?
Signup and view all the answers
Flashcards are hidden until you start studying
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.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
