Chapter 6 Flashcards
What is a gene pool?
The collection of alleles from all individuals in a population
Gene pools are essential for understanding genetic diversity within a population.
Define alleles.
Different forms of a particular gene
Alleles can result in variations in traits among individuals.
What is a mutation?
A random change in the sequence of nucleotides in DNA
Mutations can affect gene function and contribute to genetic diversity.
What is genetic drift?
A process that occurs when genetic variation is lost due to random variation in mating, mortality, fecundity, and inheritance
Genetic drift can significantly impact small populations.
What does the bottleneck effect refer to?
A reduction of genetic diversity in a population due to a large reduction in population size
The bottleneck effect can lead to increased inbreeding and decreased adaptability.
What is the founder effect?
When a small number of individuals leave a large population to colonize a new area
The founder effect can limit genetic variation in the new population.
Define selection in the context of evolution.
The process by which certain phenotypes are favored to survive and reproduce over others
Selection is a key mechanism of evolution.
What is stabilizing selection?
When individuals with intermediate phenotypes have higher survival and reproductive success
Stabilizing selection reduces variation and maintains the status quo for a particular trait.
What is directional selection?
When individuals with an extreme phenotype experience higher fitness than the average phenotype
Directional selection can lead to significant changes in trait distributions over time.
Define microevolution.
The evolution of populations
Microevolution focuses on changes within a species or population over time.
What is artificial selection?
Selection in which humans decide which individuals will breed
Artificial selection is commonly used in agriculture and animal breeding.
What is macroevolution?
Evolution at higher levels of organization, including species, genera, families, orders, and phyla
Macroevolution encompasses major evolutionary changes over long time periods.
Define speciation.
The evolution of new species
Speciation can occur through various mechanisms, including geographic and reproductive isolation.
What are phylogenetic trees?
Hypothesized patterns of relatedness among different groups such as populations, species, or genera
Phylogenetic trees illustrate evolutionary relationships and history.
What is allopatric speciation?
The evolution of new species through the process of geographic isolation
Allopatric speciation often occurs when a population is divided by a physical barrier.
Define sympatric speciation.
The evolution of new species without geographic isolation
Sympatric speciation can occur through mechanisms like polyploidy or behavioral changes.
What does polyploid mean?
A species that contains three or more sets of chromosomes
Polyploidy is common in plants and can lead to speciation.
