Chapter 6- Evolutionary History

What is a gene pool?

The collection of alleles from all individuals in a population.

What are alleles?

Different forms of a particular gene.

What does gene frequency refer to?

How common an allele is in a population.

What is a mutation?

A random change in DNA sequence that can introduce new alleles into a population.

What is recombination?

The process of exchanging genetic material between chromosomes during meiosis.

What is random assortment?

The random distribution of alleles from different genes to gametes.

What is genetic drift?

The process where variation is lost due to random variation in mating, mortality, fecundity, and inheritance.

What is the bottleneck effect?

When a population’s size is severely reduced, leading to a loss of genetic diversity.

What is the founder effect?

When a small number of individuals leave a large population to colonize a new area, bringing a small amount of genetic variation.

How does selection contribute to evolution?

Certain organisms are more likely to survive and reproduce than others, leading to evolutionary change.

What is stabilizing selection?

A natural selection process that favors average traits over extreme traits.

What is directional selection?

A selection process where individuals with one extreme trait have a better chance of surviving and reproducing.

What is disruptive selection?

A natural selection process that favors organisms with extreme traits over those with intermediate traits.

What is microevolution?

The evolution of populations.

What is artificial selection?

Humans decide which individuals will breed based on desired traits.

What is industrial melanism?

Industrial activities cause habitats to become darker, favoring individuals with darker phenotypes.

What is macroevolution?

Evolution that occurs at higher levels of organization, including species, genera, families, orders, and phyla.

What is speciation?

The evolution of new species.

What is allopatric speciation?

The evolution of new species through geographic isolation.

What is sympatric speciation?

The evolution of new species without geographic isolation.

What is polyploidy?

A species that contains three or more sets of chromosomes.