microevolution and speciation Flashcards
(14 cards)
How is genetic variation stored?
In the gene pool
The gene pool refers to the complete set of genetic information within a population.
How do allele frequencies change in a population?
Through mechanisms like natural selection, genetic drift, mutation, and gene flow
Changes in allele frequencies can indicate evolutionary processes at work.
What are sources of variation within a population?
Mutation, gene flow, and sexual reproduction
Each of these sources contributes to the genetic diversity within a population.
How do you calculate allele frequencies?
By dividing the number of copies of a specific allele by the total number of alleles in the population
This calculation helps in understanding the genetic structure of a population.
What is the relationship between allele frequency and gene pool?
Allele frequency reflects the genetic diversity of the gene pool
A higher diversity in allele frequencies indicates a richer gene pool.
What are the three types of selection?
Directional selection, stabilizing selection, disruptive selection
Each type of selection affects allele frequencies in different ways.
What happens in directional selection?
One extreme phenotype is favored over others
This can lead to a shift in the population’s trait distribution.
What happens in stabilizing selection?
Intermediate phenotypes are favored
This type of selection reduces variation and maintains the status quo.
What happens in disruptive selection?
Both extreme phenotypes are favored over intermediate phenotypes
This can lead to speciation as it encourages divergence.
What is microevolution?
Small-scale evolutionary changes within a population
Microevolution focuses on changes in allele frequencies over time.
How can allele frequencies indicate microevolution?
By showing consistent changes in allele proportions over generations
Monitoring these changes can reveal evolutionary trends.
How can data on allele frequencies determine if natural selection has occurred?
By identifying consistent shifts towards advantageous alleles
Such shifts suggest that certain traits are being selected for due to environmental pressures.
What are mechanisms for evolution other than natural selection?
Genetic drift, mutation, gene flow
These mechanisms can also lead to changes in allele frequencies.
Describe two ways populations can become small enough to experience genetic drift.
Bottleneck effect and founder effect
Both scenarios can reduce genetic diversity and increase the impact of random genetic changes.
